Turck NI50-CP80-FZ3X2 Inductive Proximity Sensor | Ident no. 13406 | Increased Switching Distance 50mm | Non-flush Mounting | Rectangular 80×80×41mm | 2-wire AC/DC Universal | 20-250VAC | 10-300VDC |

1. Product Overview

The Turck NI50-CP80-FZ3X2 (Ident no. 13406) Inductive Proximity Sensor is an increased switching distance rectangular proximity switch from Turck's NI50 series, specifically designed for non-contact detection of metallic objects in industrial automation. It can accurately detect the presence, position, and motion state of metallic objects without physical contact, widely applied in position detection, limit protection, counting, speed measurement, position confirmation and other industrial automation scenarios.

The working principle of inductive proximity sensors is based on electromagnetic induction (eddy current effect): the internal LC oscillator circuit generates a high-frequency alternating electromagnetic field at the sensor sensing face. When a metallic object enters this electromagnetic field, eddy currents are induced inside the metal object, consuming energy from the oscillator circuit and causing oscillation amplitude attenuation or even stoppage. The internal detection circuit recognizes the change in oscillation amplitude and converts it into a switching signal output. Based on the electromagnetic induction principle, inductive sensors can only detect metallic objects (iron, stainless steel, copper, aluminum, etc.), and cannot detect non-metallic objects (such as plastic, wood, glass, water, etc.). The detection distance varies for different metal materials (ferromagnetic metals have the longest detection distance, non-ferromagnetic metals have shorter detection distance).

A significant feature of the NI50-CP80-FZ3X2 is its increased switching distance design. Conventional 80mm rectangular inductive sensors typically have a rated detection distance of 20-25mm, while this product, through optimized oscillator circuit design and coil structure, increases the rated switching distance (Sn) to 50mm, more than twice that of standard sensors of the same size. Increased switching distance brings the following advantages: ① Can detect metallic objects at a greater distance, reducing the risk of collision between the sensor and the detected object, protecting the sensor; ② Can accommodate larger installation tolerances and detected object position deviations, reducing installation and commissioning difficulty; ③ Can detect smaller metallic objects or detect through larger gaps; ④ Has irreplaceable advantages in special applications (such as detection through thick walls, long-distance limit detection).

The product adopts non-flush mounting. Non-flush mounting means the sensor sensing face cannot be surrounded by metal; the sensor needs to protrude a certain distance from the mounting surface (usually 1-2 times the sensor side length), and a certain non-metallic space needs to be left around it. Non-flush mounted sensors have larger detection distance compared to flush mounted sensors, because surrounding metal in flush mounting weakens the electromagnetic field and reduces detection distance. The 50mm rated detection distance of this product is calibrated under non-flush mounting conditions. During installation, attention should be paid to the distance of metallic objects around the sensor to avoid surrounding metal affecting detection distance and switching point.

In terms of electrical performance, the NI50-CP80-FZ3X2 adopts 2-wire output, AC/DC universal, with a very wide operating voltage range: AC 20…250 VAC, DC 10…300 VDC. This wide voltage design allows the sensor to directly adapt to various industrial control power supplies, whether traditional 220VAC relay control systems, 24VDC PLC control systems, or 110VAC/DC control systems, all can be used directly without additional power conversion modules, greatly improving sensor versatility and convenience. 2-wire sensors have only two wires (power line and output line shared), simple wiring, saving cable cost, but note that 2-wire sensors have a certain leakage current in the off state (usually a few milliamps), when driving low-power relays or PLC inputs, need to confirm that leakage current does not cause false operation.

Connection programmable output is another practical feature of this product. The sensor output can be selected as normally open (NO) or normally closed (NC) via wiring method: when no metal is detected, the output is open (NO) or closed (NC); when metal is detected, the output state flips. This programmable design allows one model to adapt to two output logic requirements, reducing spare part types, facilitating field replacement and commissioning. Users only need to follow the wiring diagram in the product manual and select the corresponding wiring method to set the output logic, no additional programming tools or software required.

In terms of mechanical structure, the product adopts a rectangular housing with dimensions of 80mm×80mm×41mm (CP80 specification), a commonly used rectangular sensor size in industrial automation. Rectangular housing has the following advantages compared to cylindrical sensors: ① Large mounting surface, stable installation, strong vibration resistance; ② Large sensing face area, wide detection range, high tolerance for detected object position deviation; ③ Position and angle can be flexibly adjusted via mounting brackets; ④ Suitable for surface mounting, rail mounting and other scenarios. The housing material is PBT-GF30-V0, i.e., PBT (Polybutylene Terephthalate) engineering plastic reinforced with 30% glass fiber, flame retardant grade UL94 V0. This material has high strength, impact resistance, corrosion resistance, temperature resistance, flame retardant and other characteristics, suitable for long-term use in harsh industrial environments.

Electrical connection adopts terminal chamber method. The sensor tail has a removable terminal chamber cover with internal wiring terminals. Users can directly connect cables to the terminals without special connectors. Advantages of terminal chamber method: ① Flexible field wiring, any cable specification can be used (as long as wire diameter fits terminals); ② No need to purchase special connector cables, reducing cost; ③ Large space inside terminal chamber, convenient wiring operation; ④ Suitable for use in control cabinets or protected environments. The terminal chamber cover is usually fixed by screws, protection class IP67, ensuring dust and water protection at the wiring part.

Product protection class is IP67 (IEC 60529 standard), where "6" means complete protection against dust ingress (dust-tight), "7" means can be briefly immersed in 1 meter deep water at normal temperature and pressure without water ingress. IP67 protection class allows the sensor to operate reliably in dusty, humid, water-splash or even short-time immersion industrial environments, such as wash-down environments in food & beverage industry, outdoor equipment, car wash equipment, water treatment equipment. Note that IP67 does not guarantee long-term use under high-pressure water jet (IP69K) or high-temperature high-humidity environments, special environments require higher protection class products.

In terms of environmental adaptability, product operating temperature range is -25…+70°C, can be used in cold regions and high-temperature industrial environments. Temperature drift is 10% (i.e., within operating temperature range, maximum deviation of detection distance due to temperature change is 10%), a typical characteristic of inductive sensors. In high-precision applications, temperature compensation or re-calibration of switching point under actual operating conditions should be considered. Repeat accuracy ≤2% full scale, meaning under the same conditions, repeated detection of the same object has repeat deviation of switching point no more than 2%, ensuring detection consistency and reliability. Hysteresis is 3…15%, i.e., there is a certain difference between switching action point and reset point, to prevent output chattering when the detected object vibrates near the switching point, hysteresis design improves switching stability.

As Turck's classic increased-distance rectangular inductive sensor, the NI50-CP80-FZ3X2 has numerous successful application cases in various industries worldwide, with product quality and performance widely verified by industry. Turck is a globally leading industrial automation brand with decades of R&D and manufacturing experience in inductive sensors, products known for high reliability, high protection class, wide temperature range, long life, a preferred brand for sensors in industrial automation.

2. Specifications

表格

Parameter	Value
Brand	Turck (Germany)
Model	NI50-CP80-FZ3X2
Ident no. / Order no.	13406
Product Type	Inductive Proximity Sensor
Series	NI50 series (Increased Switching Distance)
Rated Switching Distance Sn	50 mm
Mounting Conditions	Non-flush
Guaranteed Operating Distance	≤ 0.81 × Sn = ≤ 40.5 mm
Repeat Accuracy	≤ 2% of full scale
Temperature Drift	10%
Hysteresis	3…15%
Switching Frequency	20 Hz (0.020 kHz)
Design / Shape	Rectangular
Dimensions (L×W×H)	80 mm × 80 mm × 41 mm (CP80)
Housing Material	Plastic PBT-GF30-V0 (glass-fiber reinforced PBT, UL94 V0 flame retardant)
Sensing Face Material	Plastic (same as housing)
Electrical Connection	Terminal chamber
Operating Voltage (AC)	20…250 VAC (2-wire AC)
Operating Voltage (DC)	10…300 VDC (2-wire DC)
Output Type	2-wire, AC/DC universal
Output Function	Connection programmable, NO or NC selectable
Switching Capacity	To be confirmed (reference 3-400mA AC / 3-300mA DC)
Leakage Current	To be confirmed (2-wire off-state leakage, reference ≤1.5mA)
Voltage Drop	To be confirmed (reference ≤5V @ rated current)
Short-Circuit Protection	To be confirmed (2-wire usually no built-in short-circuit protection, external protection required)
Reverse Polarity Protection	To be confirmed
Overload Protection	To be confirmed
Indicator	To be confirmed (usually with LED status indicator, yellow/orange)
Correction Factor (St37 steel)	1 (standard calibration material)
Correction Factor (stainless steel)	0.7
Correction Factor (brass)	0.4
Correction Factor (aluminum)	0.3
Minimum Object Size	To be confirmed (reference ≥80×80mm steel for rated distance)
Ambient Temperature	-25…+70 °C
Storage Temperature	To be confirmed (reference -40…+85°C)
Humidity	To be confirmed (reference ≤95% RH non-condensing)
Protection Class	IP67 (IEC 60529)
Vibration Resistance	To be confirmed (reference IEC 60068-2-6)
Shock Resistance	To be confirmed (reference IEC 60068-2-27)
Certification	To be confirmed (reference CE, UL, cULus)
Weight	To be confirmed (reference approx. 150-200g)
Country of Origin	To be confirmed (Turck global manufacturing, incl. Tianjin China)
HS Code	To be confirmed (reference 85365090)
Accessories	Mounting bracket (ordered separately)
Stock Status	Order available
Warranty Period	12 months

3. Key Features

1. Increased Switching Distance 50mm, Longer Range Safer Detection — The NI50-CP80-FZ3X2 adopts increased switching distance design, rated switching distance Sn up to 50mm, more than twice that of standard 80mm rectangular inductive sensors. Increased distance can detect metallic objects at greater distance, significantly reducing collision risk between sensor and moving objects, protecting sensor from mechanical damage; accommodates larger installation tolerances and object position deviations, reducing installation difficulty; has irreplaceable advantages in special applications such as thick-wall detection, long-distance limit, small object detection.
2. 2-wire AC/DC Universal, Wide Voltage Compatibility — Adopts 2-wire output, AC/DC universal, extremely wide operating voltage range: AC 20…250VAC, DC 10…300VDC. This wide voltage design allows direct adaptation to various industrial control power supplies, whether traditional 220VAC relay systems, 110VAC systems, or 24VDC/48VDC PLC systems, all can be used directly without additional power conversion modules, greatly improving versatility and convenience, reducing spare part types. 2-wire wiring is simple, only two wires needed, saving cable cost and wiring time.
3. Connection Programmable NO/NC, One Model Two Logic — Output state connection programmable, selectable normally open (NO) or normally closed (NC) output logic via wiring method. When no metal detected, output open (NO) or closed (NC); when metal detected, output flips. This programmable design allows one model to adapt to two output logic requirements, reducing spare part types, facilitating field replacement and commissioning, no additional programming tools or software needed, just select corresponding wiring per wiring diagram to set output logic, flexibly adapting to different control systems and application needs.
4. Rectangular 80×80×41mm, Stable Mounting Wide Detection — Adopts rectangular housing design, dimensions 80mm×80mm×41mm (CP80 specification), a commonly used rectangular sensor size in industrial automation. Rectangular housing has larger mounting surface, more stable installation, stronger vibration resistance than cylindrical sensors; large sensing face area (80×80mm), wide detection range, high tolerance for object position deviation and tilt, reducing alignment requirements; position and angle flexibly adjustable via mounting brackets, suitable for surface mounting, rail mounting, frame mounting and other scenarios.
5. PBT-GF30-V0 Flame Retardant Housing, Industrial-Grade Robust — Housing material PBT-GF30-V0, PBT engineering plastic reinforced with 30% glass fiber, flame retardant grade UL94 V0. This material has high strength, impact resistance, corrosion resistance, temperature resistance, flame retardant and other excellent characteristics, mechanical strength much higher than ordinary plastic, can withstand vibration, shock, collision in industrial environments without damage; good corrosion resistance, can be used in oily, chemical, humid environments; V0 flame retardant ensures no flame spread in case of electrical fault or fire, improving equipment safety, suitable for long-term reliable operation in various harsh industrial environments.
6. Terminal Chamber Connection, Flexible Convenient Field Wiring — Electrical connection via terminal chamber, sensor tail with removable terminal chamber cover, internal screw wiring terminals. Users can directly connect any cable specification (wire diameter fitting terminals) to terminals, no special connectors or prefabricated cables needed, flexible convenient field wiring, reducing accessory cost. Large space inside terminal chamber, convenient wiring operation, suitable for use in control cabinets or protected environments. Terminal chamber cover fixed by screws, with sealing gasket achieving IP67 protection, ensuring dust and water protection at wiring part.
7. IP67 High Protection, Adaptable to Harsh Industrial Environments — Protection class IP67 (IEC 60529), complete dust ingress protection (dust-tight), and can be briefly immersed in 1m deep water at normal temperature and pressure without water ingress. IP67 allows reliable operation in dusty, humid, water-splash or even short-time immersion industrial environments, such as food & beverage wash-down, outdoor equipment, car wash, water treatment, building materials production, mining equipment. Both sensor electrical part and wiring part are sealed, ensuring long-term stable operation in harsh environments, reducing failures and maintenance cost due to environmental factors.
8. High Repeat Accuracy Low Hysteresis, Stable Reliable Detection — Repeat accuracy ≤2% full scale, under same conditions repeated detection of same object has switching point repeat deviation no more than 2%, ensuring detection consistency and reliability, suitable for counting, positioning, indexing and other high-precision applications. Hysteresis 3…15%, reasonable difference between switching action point and reset point, effectively preventing output chattering when object vibrates near switching point, improving output stability. Switching frequency 20Hz, meets most industrial position detection and low-speed counting application needs.
9. Multi-Metal Detection Correction Factors, Wide Application Range — Can detect various metallic objects, detection distance correction factors for different metals: St37 steel=1 (standard calibration material, longest distance), stainless steel=0.7, brass=0.4, aluminum=0.3. Users can convert actual detection distance according to detected object material and correction factor in practical applications, ensuring reliable detection for different metals. Ferromagnetic metals (steel, iron) have longest distance, non-ferromagnetic metals (stainless steel, copper, aluminum) shorter, a basic characteristic of inductive sensors. 50mm rated distance (steel) still has 15mm effective distance even when detecting aluminum, much larger than ordinary sensors.
10. Turck Quality, Globally Widely Industrial Verified — Turck is a globally leading industrial automation brand with decades of R&D and manufacturing experience in inductive sensors, products known for high reliability, high protection class, wide temperature range, long life. As Turck's classic increased-distance rectangular inductive sensor, the NI50-CP80-FZ3X2 has numerous successful application cases in various industries worldwide, widely applied in machine tools, automated production lines, conveyors, packaging machinery, food & beverage, pharmaceutical, automotive manufacturing, logistics & warehousing, elevators, lifting equipment, etc., product quality and performance widely verified by industry, a reliable choice for industrial automation position detection.

4. Typical Applications

• Machine Tool Limit & Homing Detection: On CNC lathes, milling machines, machining centers, grinders and other machine tool axes, for travel limit (positive/negative hard limit) and reference point (homing) detection, when metal stopper passes sensor outputs switching signal, notifying control system axis has reached limit or reference point, preventing overtravel collision, ensuring machine coordinate accuracy
• Automated Production Line Station Detection: On assembly lines, welding lines, painting lines, final assembly lines and other automated production lines, for workpiece in-position detection, station occupancy detection, process completion confirmation, workpiece type identification (via different size metal parts), ensuring production line runs automatically per cycle, preventing workpiece misalignment or missing process
• Conveyor Material Detection: On belt conveyors, roller conveyors, chain conveyors, elevators and other conveying equipment, for metal workpiece/material presence detection, counting, congestion detection, drop confirmation, full material detection, achieving automated monitoring and management of material conveying, preventing material accumulation or idling
• Packaging Machinery Position Detection: On packaging machines, filling machines, carton sealers, labeling machines, palletizers and other packaging equipment, for packaging material in-position detection, box/bottle detection, sealing position detection, label detection, pusher cylinder in-position detection, palletizing layer detection, ensuring packaging process accuracy and continuity
• Food & Beverage Equipment Detection: On food processing equipment, beverage filling lines, sterilization equipment, cleaning equipment (CIP/SIP), conveyors and other food & beverage equipment, for metal can/cap detection, equipment component position detection, cylinder in-position detection, guard door detection. IP67 protection suitable for humid and wash-down food & beverage environments, PBT-GF30-V0 material meets food equipment material requirements
• Pharmaceutical Machinery Detection: On tablet presses, capsule filling machines, packaging lines, sterilizers, powder handling equipment and other pharmaceutical machinery, for metal component position detection, die in-position detection, tablet position detection, guard door detection, cylinder in-position detection, ensuring precise operation and safety protection of pharmaceutical equipment, complying with GMP requirements
• Automotive Manufacturing Detection: On automotive body welding lines, painting lines, final assembly lines, engine production lines, transmission production lines and other automotive manufacturing equipment, for body in-position detection, fixture clamping confirmation, welding gun position detection, conveyor skid detection, workpiece positioning detection, bolt tightening in-position detection, basic detection elements for automotive automated production lines
• Logistics & Warehousing Detection: On automated storage & retrieval systems (AS/RS), AGVs (Automated Guided Vehicles), shuttles, sorters, stackers, conveyors and other logistics & warehousing equipment, for cargo in-position detection, shelf position detection, AGV station detection, sorting position detection, stacker positioning, cargo size detection (metal pallets), achieving precise position control in logistics automation
• Elevator & Escalator Detection: In elevator, escalator, moving walkway control systems, for car position detection, leveling detection, up/down final limit, deceleration switch, escalator entrance detection, step missing detection, handrail speed detection (metal components), ensuring safe operation and precise leveling of elevators and escalators
• Lifting Equipment Detection: On overhead cranes, gantry cranes, tower cranes, electric hoists and other lifting equipment, for bridge/trolley travel limit, hoisting height limit, overload detection (with metal components), hook position detection, buffer position detection, windproof rail clamp status detection, preventing overtravel and overload, ensuring lifting operation safety
• Woodworking Machinery Detection: On panel saws, edge banders, multi-boring machines, engraving machines, planers and other woodworking machinery, for worktable position detection, saw blade/tool position detection, workpiece in-position detection, hold-down cylinder status detection, safety guard detection, feed position detection, ensuring precise machining and operation safety of woodworking machinery
• Rubber & Plastic Machinery Detection: On injection molding machines, extruders, blow molding machines, vulcanizing machines, mixers and other rubber & plastic equipment, for mold open/close position detection, ejector in-position detection, injection position detection, extruder material detection (metal detection), safety door detection, manipulator position detection, ensuring precise operation and safety protection of rubber & plastic equipment
• Metal Processing & Detection: On metal cutting machines, stamping presses, bending machines, welding equipment, for metal sheet in-position detection, stamping position detection, bending angle detection (metal components), weld tracking (metal detection), workpiece counting, die position detection, basic detection elements for metal processing automation
• Textile Machinery Detection: On spinning machines, looms, knitting machines, dyeing machines, finishing machines and other textile equipment, for metal component position detection, beam in-position detection, fabric roll detection, spindle position detection, cylinder status detection, guard door detection, ensuring continuous operation and product quality of textile equipment
• Building Materials Production Detection: On cement plants, glass factories, ceramic factories, brick & tile factories and other building materials production lines, for metal equipment component position detection, kiln position detection, crusher status detection, conveyor material detection (metal liners/chains), valve position detection, adapting to dusty, high-temperature, vibrating harsh environments in building materials industry
• Water Treatment & Environmental Equipment Detection: On sewage treatment plants, water purification plants, desulfurization & denitrification equipment, dust removal equipment and other water treatment & environmental equipment, for valve position detection, gate opening detection (metal components), scraper position detection, filter bag frame detection, cylinder status detection, IP67 protection suitable for humid water treatment environments
• Energy & Power Equipment Detection: On wind turbines, solar tracking systems, hydropower stations, substations and other energy & power equipment, for blade position detection (metal components), tracking angle detection, hydro turbine guide vane position detection, circuit breaker status detection, disconnector position detection, transformer component detection, ensuring safe operation of energy equipment
• Equipment Retrofit & Safety Upgrade: For automation retrofit of older equipment, adding position detection, limit protection, counting functions to traditional equipment, improving automation level and safety; also for equipment safety protection upgrade, adding safety door detection, position limit and other safety functions to hazardous areas, meeting safety standard requirements
• Spare Part Replacement & System Maintenance: As inductive sensor spare parts for in-service automation equipment, for faulty sensor replacement and system maintenance, ensuring continuous effective equipment detection function, reducing downtime. Turck sensors have high model standardization, good interchangeability within same series, convenient spare part management and replacement

5. Model Explanation

Product Model: NI50-CP80-FZ3X2

Ident no. / Order no.: 13406

Product Description: Inductive Sensor, Increased Switching Distance, 50mm, Non-flush, Rectangular 80×80×41mm, 2-wire AC/DC, 20-250VAC / 10-300VDC, Connection Programmable NO/NC, Terminal Chamber, IP67

Model Code Breakdown NI50-CP80-FZ3X2:

表格

Code Segment	Meaning	Description
NI	Product Series	NI series inductive proximity sensor
50	Rated Detection Distance	50mm (increased switching distance type)
CP80	Dimensions	CP = Compact Plastic, 80 = 80×80mm cross-section, height 41mm
F	Output Type	F = 2-wire AC/DC
Z3	Output Function	Z3 = Connection programmable (NO/NC selectable)
X2	Connection Method	X2 = Terminal chamber

Ident no. Explanation:

• 13406 is Turck standard ident number (order no.)
• Used for procurement and order tracking, one-to-one correspondence with model

Key Parameters Summary:

表格

Parameter	Value
Product Type	Inductive proximity sensor
Rated Detection Distance Sn	50mm
Mounting	Non-flush
Dimensions	80×80×41mm (rectangular)
Housing Material	PBT-GF30-V0
Operating Voltage	20-250VAC / 10-300VDC
Output Type	2-wire, AC/DC universal
Output Function	Programmable NO/NC
Connection	Terminal chamber
Switching Frequency	20Hz
Repeat Accuracy	≤2%
Protection Class	IP67
Operating Temperature	-25…+70°C

NI50-CP80 Series Common Models Comparison:

表格

Model	Ident no.	Output Type	Operating Voltage	Connection	Features
NI50-CP80-FZ3X2	13406	2-wire AC/DC	20-250VAC/10-300VDC	Terminal chamber	This product, programmable NO/NC
NI50-CP80-FZ3X2/S10	13416	2-wire AC/DC	20-250VAC/10-300VDC	Terminal chamber + 1/2NPT base	Special version with threaded mounting base
NI50-CP80-VP4X2	15696	4-wire DC PNP	10-65VDC	Terminal chamber	PNP output, NO+NC
NI50-CP80-VN4X2	-	4-wire DC NPN	10-65VDC	Terminal chamber	NPN output, NO+NC
NI50-CP80-AP6X2	-	2-wire DC	10-65VDC	M12 connector	DC 2-wire, M12 connector
NI50-CP80-FDZ30X2	-	2-wire AC/DC	20-250VAC/10-300VDC	Terminal chamber	High temperature type (-25…+100°C)

Compatible Accessories (ordered separately):

• Mounting bracket: for fixing sensor to equipment
• Reflector / standard target: for calibration and testing
• Cables (if using connector version)

Brand: Turck, German industrial automation brand, globally leading supplier of sensors, fieldbus and interface technology

Official Documentation:

• NI50-CP80-FZ3X2 Datasheet
• NI50-CP80-FZ3X2 Operating Instructions
• Turck Inductive Sensors Catalog
• Conformity Declaration

6. Installation & Usage Instructions

Pre-Installation Preparation:

• Confirm product model (NI50-CP80-FZ3X2) and ident no. (13406) match design requirements
• Confirm detected object is metallic (steel, stainless steel, copper, aluminum, etc.), inductive sensors cannot detect non-metals
• Convert actual detection distance according to detected object material and size using correction factors, confirm sensor detection distance meets application requirements
• Confirm operating voltage (20-250VAC or 10-300VDC) matches field control power supply
• Confirm output logic requirement (NO or NC), prepare to wire per corresponding method
• Prepare installation tools (screwdriver, wrench, drill, multimeter, etc.)
• Prepare mounting brackets (if needed) and fixing screws
• Prepare control cables (select appropriate cross-section according to voltage and current, recommended 0.5-1.5mm²)
• Read product installation instructions and safety precautions
• Confirm installation location and environment: avoid strong magnetic fields, strong vibration, high temperature, corrosive gases

Installation Notes:

• Installation and wiring must be performed in de-energized state, ensuring personal and equipment safety
• Non-flush mounting requirements: sensor sensing face cannot be surrounded by metal, sensor must protrude from mounting surface, sufficient non-metallic space must be left around
  • Distance between sensor side and surrounding metal objects recommended ≥20mm (specific per product manual installation drawing)
  • Distance between metal mounting plate behind sensor sensing face recommended ≥10mm
  • When multiple sensors installed side by side, distance between sensors recommended ≥80mm (center-to-center), avoid mutual interference
• Installation position should ensure detected object passes perpendicular to sensor sensing face, through sensing face center area, to obtain maximum detection distance
• Detected object size should be sufficiently large (recommended ≥80×80mm steel for rated 50mm distance), small objects have shorter detection distance
• Sensor should be firmly installed, using mounting brackets or screws, avoid loosening in vibrating environments
• Avoid installing sensor near strong magnetic fields (such as large motors, transformers, electromagnets), strong magnetic fields may interfere with sensor oscillator circuit, causing false operation
• Avoid installing sensor in strong vibration and strong impact positions, long-term strong vibration may damage internal circuits
• Sensor cables should be routed separately from power cables, avoid parallel routing, reduce electromagnetic interference
• Terminal chamber cover must be tightened, sealing gasket intact, ensuring IP67 protection
• Before first power-on, check all wiring, confirm voltage polarity (DC positive/negative), no short circuit

Wiring Instructions:

2-wire Wiring Basic Principle:

• 2-wire sensor has only two wires: one to power positive (L+/+), one to load (relay coil / PLC input), other end of load to power negative (N/-)
• Sensor and load are connected in series in circuit, when sensor conducts current flows through load, load operates (e.g., relay pulls in)
• 2-wire sensor has tiny leakage current in off state, need to confirm leakage current does not cause low-sensitivity load false operation

Output Logic Selection (Programmable NO/NC):

• Product selects normally open (NO) or normally closed (NC) output via wiring method, specific wiring per product manual wiring diagram
• Normally Open (NO): when no metal detected output open (load not operate), when metal detected output closed (load operates)
• Normally Closed (NC): when no metal detected output closed (load operates), when metal detected output open (load not operate)
• Safety-related applications (such as limit protection) usually recommend NC output, because wire break or fault causes output open, triggering safety stop (fail-safe principle)

AC Wiring Example (220VAC):

• L (live) → sensor power terminal (brown wire / terminal 1)
• Sensor output terminal (black wire / terminal 2) → relay coil A1
• Relay coil A2 → N (neutral)
• Relay contacts → control circuit

DC Wiring Example (24VDC):

• +24V → sensor power terminal (brown wire / terminal 1)
• Sensor output terminal (black wire / terminal 2) → PLC digital input module input
• PLC input common → 0V
• Note: when 2-wire sensor connects to PLC input, confirm PLC input type (source/sink) matches sensor, and leakage current does not cause PLC input false trigger

Terminal Chamber Wiring:

• Open terminal chamber cover (loosen fixing screws)
• Pass cable through cable entry, reserve sufficient wiring length
• Strip wire end insulation (approx. 5-7mm)
• Connect wire to corresponding terminal, tighten terminal screw
• Gently pull wire, confirm wiring firm and not loose
• Confirm cable gland (or cable seal) tightened, ensuring protection rating
• Seal unused cable entries with blind plugs
• Close terminal chamber cover, tighten fixing screws

Notes:

• 2-wire sensor has no separate power and output wires, power and output share two wires, pay attention to distinction during wiring
• In DC applications pay attention to power positive/negative, reversed connection may cause sensor not work or damage
• Load (relay/PLC input) rated voltage and current should be within sensor switching capacity
• Inductive loads (such as relay coils) recommend parallel flyback diode (DC) or RC absorber (AC), protecting sensor output
• When multiple sensors in parallel, pay attention to total leakage current and load matching
• After wiring completion measure power supply voltage with multimeter, confirm within operating range

Configuration & Commissioning:

1. Confirm sensor installed in place, firmly fixed, sensing face facing detected object movement direction
2. Confirm wiring correct, output logic (NO/NC) meets application requirement
3. Power on, observe sensor status indicator (if any):
   • No metal detected: indicator off (NO) or on (NC)
   • Metal detected: indicator on (NO) or off (NC)
4. Static detection test:
   • Slowly move standard metal target (e.g., 80×80mm steel) toward sensor sensing face
   • Observe sensor output state flip position (action point), record detection distance
   • Slowly move metal away, observe output reset position (reset point), confirm hysteresis normal
   • Repeat multiple times, confirm switching point stable, no chattering
5. Dynamic detection test:
   • Let detected object pass sensor detection area at actual working speed
   • Observe sensor output waveform with oscilloscope or PLC monitor
   • Confirm each pass reliably detected, no false detection, no missed detection
   • Confirm output pulse width meets control system requirement (switching frequency 20Hz, i.e., fastest 50ms per cycle)
6. Actual operating condition test:
   • Test sensor detection reliability under equipment actual operating conditions
   • Test detection effect at different positions, different speeds, different temperatures
   • Confirm reliable detection under worst conditions (maximum distance deviation, highest speed, highest/lowest temperature)
7. Adjust installation position:
   • If detection distance insufficient, adjust sensor position, reduce distance to detected object
   • If false detection (detecting surrounding metal), adjust sensor position or add non-metallic isolation
   • If missed detection, check detected object size/material, detection distance, installation alignment
8. Fix sensor, record installation position, wiring method, output logic, detection distance and other parameters, include in project documentation
9. Recommend performing detection function verification during equipment commissioning and regular maintenance

Usage Notes:

• Inductive sensors can only detect metallic objects, cannot detect non-metals (plastic, wood, glass, water, human body, paper, etc.), confirm application scenario suitable
• Different metals have different detection distances: steel/iron longest, stainless steel medium, copper/aluminum shorter, convert per correction factors
• Smaller detected object size means shorter detection distance, confirm object size meets detection distance requirement
• Non-flush mounted sensors cannot have metal surrounding them, otherwise detection distance reduces significantly or even stops working
• Multiple sensors installed close together may interfere, maintain sufficient spacing (recommended ≥80mm center-to-center)
• Avoid use in strong magnetic field environments, strong magnetic fields may interfere with sensor
• 2-wire sensors have leakage current in off state, when driving low-power relays or PLC inputs pay attention to confirm no false operation
• Sensor output contact capacity is limited, do not directly drive high-power loads, should switch via intermediate relay
• Inductive loads should have parallel protection elements (flyback diode / RC absorber), protecting sensor
• Regularly clean sensor sensing face, avoid metal debris, oil, dust accumulation affecting detection
• Regularly check mounting screws for looseness, cables for damage
• Sensor is solid-state electronic device, no moving parts, long life, but should still regularly check function
• Avoid scratching sensing face with sharp objects, avoid heavy impact on sensor
• Product housing is plastic, avoid contact with organic solvents, strong acids, strong alkalis and other corrosive substances
• Discarded sensors should be disposed of per e-waste regulations

Maintenance Recommendations:

• Daily inspection: Check sensor appearance for damage, indicator status normal, installation firm
• Monthly check: Clean sensing face, check cables and wiring, check mounting screws, test detection function
• Quarterly maintenance: Thoroughly clean sensor and surrounding area, check terminal chamber seal, test detection distance and repeat accuracy, check surrounding metal objects for changes
• Annual calibration: Perform complete detection function test (action point, reset point, hysteresis, repeat accuracy, different material detection distances), record data, compare with initial values to evaluate aging status, replace if necessary
• Spare parts: Recommend stocking appropriate quantity of same model sensors as spare parts for quick replacement in case of failure
• When replacing sensor use same model, after replacement re-perform detection function verification and position adjustment

Safety Notes:

• Installation and maintenance must be performed in de-energized state, confirm equipment stopped and no residual motion
• When sensor used in safety-related applications (such as limit protection, safety door detection), safety assessment should be performed, confirm sensor safety integrity level (SIL/PL) meets application requirements; high safety level applications should use dedicated safety sensors or redundant configuration
• Do not short-circuit or bypass sensor output, this may cause safety function failure
• When 2-wire sensor wire breaks output opens (equivalent to NC state flip), in safety applications should utilize this characteristic for fail-safe
• Sensor failure (non-operation or false operation) may cause equipment out of control, critical applications should have redundant detection or other safety measures
• When installing and commissioning sensors near moving equipment, pay attention to prevent being hit or squeezed by moving parts
• Avoid outdoor sensor installation and maintenance during thunderstorms
• Discarded sensors contain electronic components and metals, should be disposed of per environmental regulations, not 随意 discarded

7. Why Choose Us

1. Professional Procurement Channel, Quality Guaranteed — All products obtained through professional procurement channels, ensuring genuine Turck original products, with product identification and quality documents, provides 12-month quality warranty. Appearance check, model confirmation, ident number verification, and packaging verification performed before shipment, ensuring delivered products are intact and model-accurate.
2. Worldwide Delivery — Supports DHL, FedEx, UPS and other international couriers. Can also ship via your designated freight forwarder to 200+ countries, can arrange project site delivery and port delivery. Industrial sensors use shock-proof, moisture-proof, anti-static professional packaging, ensuring transportation safety.
3. Professional Technical Support — Provides selection consultation (confirming detection distance, mounting method, output type, operating voltage, connection method, detected object material matching), installation guidance (non-flush mounting spacing requirements, terminal chamber wiring method, NO/NC output logic selection), commissioning support (detection distance calibration, repeat accuracy testing, anti-interference optimization), fault diagnosis (false/missed detection cause analysis, surrounding metal interference troubleshooting, wiring problem troubleshooting) and spare part replacement suggestions, helping you correctly select and successfully commission.
4. Flexible Procurement — Supports single sensor procurement and bulk project orders, tiered pricing discounts with quantity. Can provide whole-station sensor spare part packages (inductive + photoelectric + capacitive + proximity switch combination) and annual spare part framework agreements. For automation project overall needs, can provide sensor selection list and bulk supply support.
5. Pre-shipment Inspection — Appearance check, packaging verification, model confirmation, ident number verification performed before shipment. Power-on function test report (detection distance, output logic, indicator status) can be provided if necessary, ensuring delivered products have accurate models and qualified performance.

8. Frequently Asked Questions (FAQ)

Q1: What is this NI50-CP80-FZ3X2 sensor? What can it detect? How far is the detection distance?

A: The NI50-CP80-FZ3X2 is a Turck inductive proximity sensor, ident no. 13406, an industrial sensor for non-contact detection of metallic objects.

Working principle:

• Sensor internal LC oscillator circuit generates high-frequency alternating electromagnetic field at sensing face
• When metallic object enters electromagnetic field, eddy currents induced inside metal, consuming oscillator energy, causing oscillation attenuation or stoppage
• Detection circuit recognizes oscillation change, outputs switching signal
• Can only detect metallic objects (steel, iron, stainless steel, copper, aluminum, brass, etc.), cannot detect non-metals (plastic, wood, glass, water, human body, paper, etc.)

Key parameters:

• Rated switching distance Sn: 50mm (increased distance type, more than 2x standard type)
• Mounting: Non-flush (sensing face cannot be surrounded by metal)
• Guaranteed operating distance: ≤0.81×Sn = ≤40.5mm
• Dimensions: 80×80×41mm (rectangular)
• Operating voltage: 20-250VAC / 10-300VDC (2-wire AC/DC universal)
• Output: 2-wire, connection programmable NO/NC
• Connection: Terminal chamber
• Protection class: IP67
• Operating temperature: -25…+70°C
• Switching frequency: 20Hz

Actual detection distance for different metals (correction factors):

表格

Metal Material	Correction Factor	Actual Distance at 50mm Rated
St37 steel / iron	1.0	50mm (standard calibration material)
Stainless steel	0.7	approx. 35mm
Brass	0.4	approx. 20mm
Aluminum	0.3	approx. 15mm

Simply put: This is a "metal detector", rectangular box shape (8cm×8cm), can detect presence of metallic objects within up to 5cm (steel) distance, when detected outputs a switching signal (can be set NO or NC). Both AC and DC power work (20-250V AC or 10-300V DC), terminal chamber wiring, dust-proof and water-proof (IP67), used on industrial equipment to detect metal part position, limit, counting, etc. Note: only detects metal, cannot detect plastic, wood, water and other non-metallic things.

Q2: What does non-flush mounting mean? What is the difference from flush mounting? What to 注意 during installation?

A: Flush and non-flush are two installation methods for inductive sensors, main difference is whether sensor sensing face can be surrounded by metal, and detection distance size.

Flush Mounting (Flush / Embeddable):

• Sensor sensing face can be flush with surrounding metal mounting surface (embedded in metal), surrounding metal does not affect detection
• Sensor housing usually has metal shielding layer, confining electromagnetic field directly in front of sensing face
• Advantage: can be embedded in metal installation, aesthetically pleasing, not afraid of surrounding metal influence
• Disadvantage: shorter detection distance (because electromagnetic field is shielded and confined)

Non-flush Mounting (Non-flush / Non-embeddable):

• Sensor sensing face cannot be surrounded by metal, must protrude from mounting surface, non-metallic space left around
• Electromagnetic field diffuses to front and sides of sensing face, larger detection distance
• Advantage: large detection distance (this product 50mm is calibrated non-flush)
• Disadvantage: surrounding cannot have metal during installation, needs protruding installation, requirements for installation space

This product NI50-CP80-FZ3X2 is non-flush mounting, must pay attention during installation:

1. Sensor must protrude from mounting surface:
   • Sensor sensing face should protrude at least certain distance from metal mounting plate surface (recommended ≥10-20mm, specific per product manual installation drawing)
   • Cannot completely embed sensor in metal hole flush with metal surface, otherwise detection distance significantly reduces or even stops working
2. Non-metallic space must be left around sensor sides:
   • Distance between sensor side and surrounding metal objects (mounting plate, frame, other metal components) recommended ≥20mm
   • No fixed metallic objects in detection area directly in front of sensing face (unless detected object)
   • Distance between metal mounting plate behind sensor (terminal chamber side) recommended ≥10mm
3. Maintain spacing when multiple sensors installed side by side:
   • Center-to-center distance between two sensors recommended ≥80mm (i.e., at least one sensor width)
   • Too close may cause electromagnetic field mutual interference between sensors, causing false operation or reduced detection distance
   • If must install close, can stagger arrangement or add metal shielding partition between sensors
4. Detected object passing method:
   • Detected object should approach perpendicular to sensing face direction, through sensing face center area, to obtain maximum detection distance
   • When object sweeps laterally across sensing face, detection distance may shorten
   • Detected object size recommended ≥80×80mm (steel) for rated 50mm distance, small objects have shorter distance
5. Installation fixing:
   • Firmly fix sensor using mounting bracket or screws, avoid position shift due to vibration
   • Mounting bracket recommended non-metallic material (such as plastic, aluminum), reducing influence on electromagnetic field
   • If must use metal bracket, pay attention to distance between bracket and sensor sensing face and sides
6. Post-installation verification:
   • After installation, actually test detection distance with standard metal target, confirm meets application requirements
   • If detection distance significantly lower than expected, check if surrounding metal objects too close, adjust installation position

Simple summary: Non-flush mounting means sensor should be installed "protruding", no metal 贴着 around, this way can achieve 50mm long detection distance. If embedded flush in metal, detection distance greatly reduced or even not work. During installation remember three key points: "protruding installation, leave space around, maintain spacing between sensors".

Q3: What does 2-wire AC/DC universal mean? How to wire? How to select NO/NC programmable? Does leakage current matter?

A: 2-wire AC/DC universal means sensor adopts 2-wire output, and both AC and DC power can be used (AC/DC universal), a very common output form in industrial sensors.

What does 2-wire mean?

• Sensor has only two wires: one to power supply, one to load (relay coil or PLC input)
• Sensor and load connected in series in circuit
• When sensor conducts, current flows through load, load operates (e.g., relay pulls in)
• When sensor is off, only tiny leakage current in circuit, load does not operate
• Compared to 3-wire/4-wire sensors, 2-wire wiring is simpler, lower cable cost

What does AC/DC universal mean?

• Sensor internal circuit designed to work on both AC and DC power
• Operating voltage range: AC 20…250VAC, DC 10…300VDC
• This means same sensor can be used in 220VAC relay systems, 110VAC systems, 24VDC PLC systems, 48VDC systems and various power environments
• No need to purchase different models based on power type, reducing spare part types

Wiring method:

AC wiring (220VAC example):

L (live) → sensor terminal 1 (power)
Sensor terminal 2 (output) → relay coil A1
Relay coil A2 → N (neutral)
Relay contacts → control circuit

DC wiring (24VDC example):

+24V → sensor terminal 1 (power+, usually brown wire)
Sensor terminal 2 (output, usually black wire) → PLC digital input module input
PLC input common → 0V

• Note: do not reverse positive/negative in DC wiring

How to select NO/NC programmable (Connection Programmable)?

• Sensor output logic can be selected as normally open (NO) or normally closed (NC) via wiring method
• Normally Open (NO):
  • No metal detected: output open (relay not pull in / PLC input no signal)
  • Metal detected: output closed (relay pulls in / PLC input has signal)
  • Suitable for: object in-position detection, counting, position confirmation and other applications where normally no signal
• Normally Closed (NC):
  • No metal detected: output closed (relay pulls in / PLC input has signal)
  • Metal detected: output open (relay releases / PLC input no signal)
  • Suitable for: limit protection, safety door detection and other safety-related applications (fail-safe principle: wire break/fault causes output open, triggering stop)
• How to select: specific NO/NC wiring method per product manual wiring diagram, usually by connecting load to different terminal positions, or via jumper/terminal selection in terminal chamber
• Safety applications recommend NC: because when 2-wire sensor wire breaks output opens, NC configuration triggers safety stop (fail-safe), while NO configuration may be misinterpreted as "no object detected", potential safety hazard

Does leakage current matter?

• 2-wire sensor in off state (output open), internal circuit still needs power, so tiny leakage current flows through load
• Leakage current magnitude: usually around 1-3mA (specific per product datasheet, this product to be confirmed, reference ≤1.5mA)
• Leakage current effects:
  • Driving relay/contactor coils: relay coil has certain operating power, few mA leakage current usually not enough to pull in relay, generally no effect
  • Driving PLC digital input: PLC input has turn-on threshold (usually ≥3mA or ≥5V), if leakage current close to threshold, may cause PLC input false trigger (misinterpreted as signal)
  • Driving low-power indicator/LED: small-power LED may light up at few mA, causing indicator dim light (false indication)
• How to avoid leakage current effects:
  1. Confirm load operating current/voltage much greater than current/voltage corresponding to leakage current
  2. PLC input select model with sufficient turn-on threshold, or parallel bleeder resistor (e.g., 10kΩ) across PLC input to consume leakage current
  3. When driving low-power LED, parallel resistor or use relay switching
  4. If leakage current problem serious, can select 3-wire/4-wire sensor (no leakage current when off)
• Generally: in most industrial applications (driving intermediate relays, PLC inputs), 2-wire sensor leakage current does not cause problems, as long as pay attention to load matching. This product wide voltage design, leakage current controlled within reasonable range.

Q4: Can this sensor detect stainless steel/aluminum/copper? Is detection distance the same? Can small objects be detected?

A: Yes, but detection distance differs for different metal materials, small objects also have shorter detection distance.

Detection distance for different metals (correction factors):

Inductive sensor detection distance is related to conductivity and permeability of detected metal material. Ferromagnetic metals (steel, iron) have high permeability, strong eddy current effect, longest detection distance; non-ferromagnetic metals (stainless steel, copper, aluminum) have low permeability, relatively weak eddy current effect, shorter detection distance.

表格

Metal Material	Correction Factor	Actual Distance at 50mm (steel) Rated
St37 steel / mild steel / iron	1.0	50mm (standard calibration material, longest)
Stainless steel (304/316 etc.)	0.7	approx. 35mm
Brass (copper-zinc alloy)	0.4	approx. 20mm
Aluminum / aluminum alloy	0.3	approx. 15mm
Copper (pure copper/red copper)	approx. 0.3-0.4	approx. 15-20mm

Notes:

• Correction factor means ratio of this metal's detection distance to standard steel (St37) detection distance
• For example when detecting aluminum, actual detection distance = 50mm × 0.3 = 15mm
• Different stainless steel grades have slightly different correction factors, austenitic stainless steel (304/316) approx. 0.6-0.7, martensitic/ferritic stainless steel close to steel
• Above are typical reference values, in practical applications recommend testing and calibrating with actual detected object

Can small objects be detected?

• Yes, but detection distance shortens. Inductive sensor detection distance is calibrated under standard detected object (usually square steel sheet with thickness ≥1mm, side length equal to sensor sensing face diameter/side length)
• This product 80×80mm rectangular sensing face, standard calibration object usually 80×80mm×1mm steel sheet
• When detected object size smaller than standard object, detection distance shortens, reduction degree depends on ratio of object size to sensing face:
  • Object size ≥ sensing face size (≥80×80mm): detection distance reaches rated value (50mm steel)
  • Object size 1/2 of sensing face (approx. 40×40mm): detection distance approx. 70-80% of rated value
  • Object size 1/4 of sensing face (approx. 20×20mm): detection distance approx. 40-60% of rated value
  • Smaller objects (such as M8 screw, small steel ball): detection distance may only a few millimeters, even not detected
• Object thickness also matters: steel sheet thickness <0.5mm, eddy current loss increases, detection distance shortens; thickness ≥1mm basically no effect
• Object shape also matters: solid metal sheet has longest detection distance, annular, mesh, hollow objects have shorter distance

Practical application suggestions:

1. First confirm detected object material and size, estimate detection distance per correction factor and size reduction
2. Actual test calibration: test with actual detected object at actual installation position, confirm reliable detection distance, do not completely rely on theoretical values
3. Leave sufficient margin: when designing installation position, actual detection distance should leave 30-50% margin, avoid missed detection due to temperature drift, voltage fluctuation, object position deviation
4. Small object detection: if detected object very small (<20mm), recommend selecting smaller size sensor (such as M18, M30 cylindrical), small sensors have relatively higher detection sensitivity for small objects, or install sensor closer to detected object
5. Non-ferromagnetic metal detection: if detected object is aluminum, copper etc., detection distance shorter, should install sensor closer, or select larger detection distance model
6. Multi-material mixed detection: if production line has different material metal objects, design installation position per shortest detection distance material, ensure all materials reliably detected

Simple summary: Steel/iron detection farthest (50mm), stainless steel approx. 35mm, copper/aluminum approx. 15-20mm. Smaller object means shorter detection distance, large metal sheet above 80mm can reach rated distance, small screws small parts may only a few millimeters. In actual use better test with real object, leave sufficient margin, don't use at limit distance.

Q5: Is this product in stock? What is the lead time? What is the price?

A: This model is currently in order available status, standard lead time 4-8 weeks (ordered through professional procurement channels or allocated from global inventory). The NI50-CP80-FZ3X2 is a commonly used Turck inductive sensor model with large usage, but specific inventory situation fluctuates with market.

• Price: Specific price subject to our formal quotation, price depends on purchase quantity, supply channel, whether includes technical service and other factors. Turck inductive sensors are standard industrial automation products, moderate price, bulk procurement can enjoy tiered discounts.
• Expedited service: If you have urgent needs (such as equipment fault emergency repair, urgent project commissioning, tight schedule), we can try to coordinate global stock inventory or expedited ordering, specific please contact our sales team.
• Please indicate required quantity, operating voltage (confirm AC/DC), output logic (NO/NC), application scenario, desired delivery time, and destination when inquiring, we will do our best to coordinate the fastest delivery solution and optimal price.
• If you need to purchase compatible mounting brackets, cables, other types of sensors (photoelectric, capacitive, encoders, etc.) simultaneously, we can provide whole-station sensor product package combined quotation with more favorable prices.

Q6: What to do if sensor false/missed detection? How to judge good or bad? What to 注意 when replacing?

A: Common faults and troubleshooting methods for inductive sensors:

Common faults and causes:

1. False detection (outputs signal even without metal):
   • Surrounding metal objects too close (non-flush mounting surrounding metal interference)
   • Multiple sensors too close, mutual interference
   • Strong magnetic field interference (nearby large motors, transformers, electromagnets)
   • Power supply voltage fluctuation or excessive power ripple
   • Cable routed parallel with power cable, electromagnetic interference
   • Sensor internal circuit fault (oscillator circuit abnormal)
   • 2-wire leakage current causing low-sensitivity load false operation
2. Missed detection (no output signal when metal present):
   • Detection distance too far (exceeds actual detection distance)
   • Detected object is non-metallic (inductive cannot detect non-metals)
   • Detected object is non-ferromagnetic metal such as aluminum/copper, short detection distance
   • Detected object size too small
   • Detected object does not pass through sensing face effective area (misaligned)
   • Installation method error (non-flush sensor surrounded by metal, detection distance greatly reduced)
   • Power supply voltage too low or wiring error
   • Sensor internal circuit fault (oscillator stopped, output transistor damaged)
   • Output logic setting error (NO/NC reversed, causing signal state opposite to expected)
3. Output chattering (signal on/off intermittently):
   • Detected object vibrating near switching point
   • Hysteresis too small (normal hysteresis 3-15%, if abnormally small may chatter)
   • Installation not firm, sensor vibrating
   • Power supply poor contact
   • Sensor internal circuit fault

Good/bad judgment methods:

1. Appearance inspection:
   • Housing any cracks, damage, deformation
   • Sensing face any scratches, burns, metal debris adhesion
   • Cable (if any) any damage, terminal chamber any water ingress
   • Indicator (if any) normal
2. Power-on test (simplest method):
   • Power on per correct wiring method (pay attention to voltage range and polarity)
   • Move a metal piece (such as wrench, steel sheet) close to sensing face:
     • Normal: indicator state flips (on↔off), output signal flips
     • Abnormal: indicator no change, or always on/always off
   • Remove metal piece, output should reset
   • Repeat multiple times, confirm reliable detection each time
3. Multimeter measurement:
   • Measure power supply voltage, confirm within 20-250VAC/10-300VDC range
   • 2-wire sensor: measure voltage across sensor, should have obvious change between with metal and without metal (conducting voltage drop approx. few volts, off state close to power supply voltage)
   • If sensor voltage always equals power supply voltage (not conducting), may internal open circuit
   • If sensor voltage always close to 0 (always conducting), may internal short circuit
4. Replacement method:
   • Replace with a confirmed normal same model sensor, if fault disappears indicates original sensor damaged
   • This is the fastest and most effective judgment method on site

Replacement notes:

1. Before replacement:
   • Power off, confirm equipment stopped
   • Record original sensor installation position, wiring method, output logic (NO/NC)
   • Confirm new sensor model exactly same (NI50-CP80-FZ3X2, ident no. 13406)
   • Check new sensor appearance intact
2. During replacement:
   • Remove old sensor, pay attention to save mounting washers/brackets (if any)
   • Clean mounting surface, check mounting bracket for deformation
   • Install new sensor, fix per original position and angle, ensure firm installation
   • Wire per original wiring method, confirm NO/NC logic same as original
   • Tighten terminal chamber cover, ensure seal
3. After replacement (must re-test!):
   • Power on, confirm indicator normal
   • Test detection function with metal piece, confirm output normal flip
   • Actual operating condition test: let detected object pass, confirm reliable detection, no false/missed detection
   • Confirm detection distance meets application requirement, fine-tune installation position if necessary
   • Confirm control system receives correct signal
   • Record replacement date and new sensor information, include in equipment maintenance file

Daily maintenance suggestions:

• Regularly clean sensing face (metal debris, oil, dust affect detection)
• Regularly check mounting screws for looseness
• Regularly check cables and terminal chamber seal
• Regularly verify detection function with standard metal piece
• Stock appropriate quantity of same model spare parts for convenient quick replacement

Important note: When sensor used in safety-related applications (such as limit protection), after replacement must perform complete safety function verification, confirm safety protection function normal before putting into operation.