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Company Culture ꄲ Analytical Inst. ꄲ Mettler Toledo InPro4260i/SG/425 ISM Digital pH/ORP Electrode | Order No. 52005407

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Mettler Toledo InPro4260i/SG/425 ISM Digital pH/ORP Electrode | Order No. 52005407

Mettler Toledo InPro4260i/SG/425 (Order No. 52005407) ISM digital in-line combination pH/ORP electrode, HA glass membrane, pH 0-14, 0-130°C, Xerolyt Extra polymer open junction, Argenthal silver trap, platinum solution ground, plug and measure, K8S connector, 425mm, explosion-proof. Order available.

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Product Details

1. Product Overview

The Mettler Toledo InPro4260i/SG/425 (Order No. 52005407) is an ISM digital in-line combination pH/ORP electrode from the InPro4260(i) series, with built-in temperature sensor, specifically designed for highly demanding chemical applications, providing ISM predictive diagnostics to optimize maintenance decisions and electrode lifetime.

This model adopts ISM (Intelligent Sensor Management) digital technology. Unlike traditional analog pH electrodes, the electrode has integrated analog-to-digital conversion circuitry and digital communication chip inside. pH measurement signals, temperature signals, and electrode diagnostic information are all transmitted in digital form through K8S cable to the ISM transmitter, ensuring 100% signal integrity and stability, completely eliminating electromagnetic interference, signal attenuation, and ground loop problems that analog signals suffer during long-distance transmission.

The pH-sensitive part adopts a Highly Alkali Resistant (HA) glass membrane for Tough Conditions, a special pH-sensitive glass membrane developed specifically for harsh conditions and highly alkaline media. It maintains excellent response performance and measurement accuracy across the full pH 0-14 range, effectively overcoming the "sodium error/alkaline error" problem of ordinary glass membranes at high pH values, especially suitable for strongly alkaline media, high temperature and pressure, and highly corrosive conditions in chemical processes.

The reference system is the core advantage of the InPro4260i, featuring triple advanced design:

Xerolyt Extra patented polymer reference electrolyte: A solid polymer reference electrolyte, different from traditional liquid KCl electrolyte and gel electrolyte. Xerolyt Extra is insensitive to flow variations, especially suitable for low ionic strength media and organic solvents, insensitive to anionic salts such as nitrate, sulfate, carbonate, significantly extends lifetime in the presence of organic solvents, strong acids and alkalis, and requires no electrolyte refilling — completely maintenance-free.
Open Junction: Adopts open junction design, reference electrolyte in direct contact with measured medium, no traditional ceramic/PTFE diaphragm, fundamentally solving the diaphragm clogging problem. It still measures stably in media with suspended solids, emulsions, proteins, sulfides, oils and other high-fouling substances, especially suitable for chemical, wastewater treatment and other harsh media.
Argenthal silver-ion trap: The reference system has a built-in Argenthal silver ion capture device, effectively capturing free silver ions in the reference system, preventing silver ions from reacting with sulfides, proteins etc. in the medium to form black silver sulfide precipitate that would contaminate/poison the reference system, greatly extending reference system lifetime, with obvious advantages in sulfide-containing and protein-containing media.

Solution Ground (SG) uses platinum material with dual functions: ① As solution ground electrode, eliminates ground loop interference, improves measurement stability, supports ISM advanced sensor diagnostics; ② Also serves as ORP (Oxidation-Reduction Potential) measurement electrode, allowing one electrode to measure both pH and ORP simultaneously. The platinum-plated surface of InPro4260i enables ORP measurement (typical range -1500 to +1500mV).

ISM (Intelligent Sensor Management) is the core technology highlight of the InPro4260i, providing the following functions:

Plug and Measure: The electrode can be pre-calibrated in a safe area away from the process (e.g., laboratory, maintenance room), calibration data stored in the electrode's built-in chip, and directly installed and used on site without calibration in hazardous environments, improving maintenance personnel safety and reducing downtime.
Dynamic Lifetime Indicator (DLI): Real-time monitoring of electrode aging status, dynamically calculating remaining electrode lifetime based on actual usage conditions (temperature, pH, medium, calibration history, etc.), providing early warning for replacement time, enabling predictive maintenance.
Adaptive Calibration Timer: Intelligently determines next calibration due time based on actual electrode usage and performance changes, rather than fixed-period calibration, extending calibration intervals while ensuring measurement quality, reducing maintenance workload.
Advanced sensor self-diagnostics: Continuously monitors glass membrane impedance, reference system status, solution ground status, temperature sensor status, etc., timely detecting electrode faults and performance degradation.
Electronic Data Sheet (EDS): The electrode's built-in chip stores all information including model, serial number, calibration history, maintenance records, diagnostic data, etc., enabling digital documentation management of the measurement system, meeting traceability requirements of GMP, ISO and other quality management systems.

The electrode shaft is made of glass, diameter 12mm, this model length 425mm (InPro4260i series available lengths 120mm, 225mm, 425mm), process connection Pg 13.5 thread, cable connector K8S (ISM digital dedicated connector, different from VP6 connector for analog).

Operating temperature range 0°C to 130°C, operating pressure 0 to 15 barg at 25°C, 0 to 7 barg at 130°C, capable of long-term reliable operation in high-temperature high-pressure chemical processes. Not sterilizable/autoclavable, not refillable (Xerolyt Extra polymer, maintenance-free).

Comprehensive explosion-proof certifications: CE, Mettler Toledo Quality Certificate, FM certification (IS Cl. I, II, III, Div 1, GR ABCDEFG / T6), ATEX/IECEx certification (Ex ia IIC T6 / T5 / T4 / T3 Ga / Gb), PED (Pressure Equipment Directive). Intrinsically safe design allows safe use in explosive gas hazardous areas.

The InPro4260i is Mettler Toledo's flagship digital pH/ORP electrode specifically designed for chemical processes and other highly demanding applications. It has been widely applied globally in chemical, petrochemical, pharmaceutical, metallurgy, pulp & paper industries, known for long lifetime, low maintenance, high reliability, and intelligent diagnostics — a high-end choice for online pH/ORP measurement in harsh industrial conditions.

2. Specifications

表格

Parameter	Value
Brand	Mettler Toledo (Switzerland)
Model	InPro4260i/SG/425
Order No. / Material No.	52005407
Product Series	InPro4260(i) series
Product Type	ISM digital in-line combination pH/ORP electrode (built-in temperature sensor)
Signal Type	ISM (Digital), not analog
Measurement Parameter	pH + ORP (redox, platinum SG dual-use)
pH Sensing Technology	Highly Alkali Resistant (HA) glass membrane for Tough Conditions
pH Range	0 ~ 14
ORP Range (using SG)	-1500 ~ +1500 mV (typical)
Reference System	Xerolyt Extra patented polymer electrolyte + open double junction + Argenthal silver-ion trap
Electrolyte Type	Xerolyt Extra solid polymer electrolyte (patented)
Refillable Electrolyte	No (maintenance-free)
Junction Type	Open Junction (no diaphragm, direct media contact)
Reference Element	Argenthal (Ag/AgCl with silver-ion trap)
Solution Ground / ORP Metal	Platinum
Temperature Sensor	Digital signal (ISM built-in, not PT100/PT1000 analog)
Automatic Temperature Compensation	Yes (digital, with ISM transmitter)
Operating Temperature	0 °C ~ +130 °C (32 ~ 266 °F)
Operating Pressure	0 ~ 15 barg @ 25°C; 0 ~ 7 barg @ 130°C
Shaft Material	Glass
Shaft Diameter	12 mm
Electrode Length	425 mm (optional 120/225/425mm)
Process Connection	Pg 13.5 thread
Cable Connector	K8S (ISM digital dedicated connector)
Compatible Cable	AK9 series K8S cable (ordered separately: 1m/3m/5m/10m/20m)
Compatible Transmitter	Mettler Toledo M300 ISM/M400 ISM/M700/M800 etc. ISM transmitters (ordered separately)
Sterilizable / Autoclavable	No
ISM Plug and Measure	Yes
ISM Dynamic Lifetime Indicator (DLI)	Yes
ISM Adaptive Calibration Timer	Yes
ISM Advanced Self-diagnostics	Yes
ISM Electronic Data Sheet (EDS)	Yes
Explosion-proof Certifications	FM: IS Cl. I, II, III, Div 1, GR ABCDEFG / T6; ATEX/IECEx: Ex ia IIC T6/T5/T4/T3 Ga/Gb; PED
Other Certifications	CE, Mettler Toledo Quality Certificate
Main Application	Chemical processes (highly demanding chemical applications)
Hygienic / Biocompatibility Certification	No
Response Time	To be confirmed (reference t90 < 10s, new electrode, 25°C)
Measurement Accuracy	To be confirmed (reference ±0.01pH, with ISM transmitter)
Calibration Method	Two-point calibration (ISM pre-calibration, buffers pH 4.01/7.00/9.21)
Storage Conditions	To be confirmed (reference moisturized storage, 0-50°C)
Service Life	To be confirmed (reference 6-24 months, depending on conditions, Xerolyt Extra longer lifetime)
Weight	To be confirmed (reference approx. 100-150g)
Country of Origin	To be confirmed (Mettler Toledo global manufacturing)
HS Code	To be confirmed (reference 90271000)
Stock Status	Order available
Warranty	12 months

3. Key Features

ISM Digital Technology, 100% Signal Integrity Anti-interference — Adopts ISM (Intelligent Sensor Management) digital technology, electrode built-in ADC and digital communication chip, pH/temperature/diagnostic signals all digitally transmitted, completely eliminating electromagnetic interference, signal attenuation and ground loop problems of analog signals during long-distance transmission, ensuring 100% signal integrity and stability, especially suitable for chemical sites with strong EMI near inverters, motors.
Plug and Measure, Safe and Fast Reduced Downtime — Electrode can be pre-calibrated in safe area away from process (lab/maintenance room), calibration data stored in electrode built-in chip, directly installed on site and ready to use, no need for calibration in hazardous/high-temperature/high-altitude field environments, improving maintenance personnel safety, significantly reducing downtime and maintenance workload, electrode replacement in just minutes.
Dynamic Lifetime Indicator (DLI) + Adaptive Calibration, Predictive Maintenance — ISM Dynamic Lifetime Indicator real-time monitors electrode aging, dynamically calculates remaining lifetime based on actual usage (temperature, pH, medium, calibration history), provides early replacement warning; Adaptive Calibration Timer intelligently determines next calibration time based on actual electrode performance rather than fixed period, extends calibration intervals while ensuring measurement quality, enabling predictive maintenance, reducing total lifecycle cost.
Xerolyt Extra Patented Polymer Electrolyte, Long Lifetime Maintenance-free — Adopts Xerolyt Extra patented solid polymer reference electrolyte, insensitive to flow variations, especially suitable for low ionic strength media and organic solvents, insensitive to nitrate/sulfate/carbonate anionic salts, significantly extends lifetime in organic solvents, strong acids and alkalis; no electrolyte refilling needed, completely maintenance-free, no liquid electrolyte leakage or frequent refilling issues.
Open Junction No Diaphragm, Fundamentally Solves Clogging — Adopts Open Junction design, reference electrolyte in direct contact with medium, no traditional ceramic/PTFE diaphragm, fundamentally solving diaphragm clogging problem. Still measures stably and reliably in high-fouling media with suspended solids, emulsions, proteins, sulfides, oils, high viscosity, especially suitable for chemical, wastewater treatment and other harsh media, reducing cleaning maintenance frequency.
Argenthal Silver-ion Trap, Prevents Reference Poisoning Long Lifetime — Reference system built-in Argenthal silver ion capture device, effectively captures free silver ions, prevents silver ions from reacting with sulfides/proteins in medium to form black silver sulfide precipitate that contaminates/ poisons reference system, greatly extends reference system lifetime, obvious advantages in sulfide-containing, protein-containing media, ideal choice for chemical, pharmaceutical, food industries.
High Alkali Resistant HA Glass Membrane, pH 0-14 Full Range High Accuracy — Adopts HA glass membrane developed specifically for harsh conditions and highly alkaline media, effectively overcoming "sodium error/alkaline error" of ordinary glass membranes at high pH, maintains excellent response performance and measurement accuracy across full pH 0-14 range, especially suitable for chemical strong alkali reactions, chlor-alkali, pulp & paper, alkaline cleaning and other high-pH applications, with good mechanical strength and chemical resistance.
Platinum Solution Ground (SG), pH+ORP Dual Measurement + Ground Elimination — Built-in platinum Solution Ground (SG) electrode with triple functions: ① Eliminates ground loop interference, improves measurement stability; ② Supports ISM advanced sensor diagnostics; ③ Also measures ORP/redox (typical -1500 to +1500mV), one electrode measures both pH and ORP, reducing installation points and spare part types, lowering system cost.
Wide Temp/Pressure + Explosion-proof Certifications, Safe Use in Hazardous Areas — Operating temperature 0 to 130°C, operating pressure 0 to 15bar@25°C / 0 to 7bar@130°C, adapts to high-temperature high-pressure chemical processes; comprehensive explosion-proof certifications: FM (IS Cl.I-II-III Div1 GR ABCDEFG/T6), ATEX/IECEx (Ex ia IIC T6/T5/T4/T3 Ga/Gb), PED, CE, intrinsically safe design for safe use in explosive gas Zone 0/1/2, meeting petrochemical, pharmaceutical explosion-proof requirements.
K8S Digital Connector + Pg13.5 Connection, Standard Interface Easy Installation — Adopts K8S (ISM digital dedicated) cable connector and Pg 13.5 standard process connection, easy installation, good interchangeability; compatible with AK9 series K8S cables (1m/3m/5m/10m/20m optional) and M300 ISM/M400 ISM/M700/M800 transmitters, forming complete ISM digital pH/ORP measurement system, flexible system integration, powerful diagnostic functions.

5. Model Explanation

Product Model: InPro4260i/SG/425

Order No.: 52005407

Product Description: InPro4260i series ISM digital in-line combination pH/ORP electrode, with platinum Solution Ground (SG), 425mm length, HA glass membrane, Xerolyt Extra polymer electrolyte open junction, Argenthal silver-ion trap, K8S digital connector, Pg13.5 process connection, 0-130°C, explosion-proof certified

Model Code Breakdown InPro4260i/SG/425:

表格

Code Segment	Meaning	Description
InPro4260	Product Series	InPro4260 series highly demanding chemical application combination pH/ORP electrode
i	ISM Digital	Intelligent Sensor Management digital technology (without i = analog)
SG	Solution Ground	Platinum auxiliary electrode, eliminates ground loops, supports diagnostics, also measures ORP
425	Electrode Length	425mm (optional 120/225/425mm)

InPro4260i/SG Series Common Models Comparison:

表格

Model	Order No.	Length	Description
InPro4260i/SG/120	52005381	120mm	Short version, ISM digital, with SG
InPro4260i/SG/225	52005407 (reference, confirm with mt.com)	225mm	Medium version, ISM digital, with SG
InPro4260i/SG/425	52005407	425mm	This product, long version, ISM digital, with SG

Note: Order numbers for different lengths should be confirmed with the latest Mettler Toledo official website. This product 425mm corresponding to order no. 52005407 has been confirmed by the official website.

InPro4260 Series Digital vs Analog Difference:

表格

Comparison	InPro4260i (Digital, this product)	InPro4260 (Analog)
Signal Type	ISM Digital	Analog
Cable Connector	K8S	VP6
Temperature Sensor	Digital signal	PT100 or PT1000
Plug and Measure	Yes	No
Dynamic Lifetime Indicator DLI	Yes	No
Adaptive Calibration Timer	Yes	No
Advanced Self-diagnostics	Yes	Limited
Electronic Data Sheet EDS	Yes	No
Anti-interference	Strong (digital)	Good (analog, 注意 grounding)
Cable Length	Longer (digital, up to 100m)	Limited (usually <30m)
Price	Higher	Lower
Application	High reliability, predictive maintenance, complex systems	Budget-limited, existing analog systems, simple applications

Other models in the same series:

InPro4262i/SG: pH 1-14, different glass membrane formulation variant
InPro4281i/SG: Titanium shaft, more robust impact resistant, stainless steel thread
InPro4260 (without i): Analog version, PT100/PT1000 temperature sensor, VP6 connector

Key Parameters Summary:

表格

Parameter	Value
Product Type	ISM digital in-line combination pH/ORP electrode
pH Range	0-14
Temperature Range	0 to 130°C
Pressure Range	0 to 15bar@25°C, 0 to 7bar@130°C
Glass Membrane	Highly Alkali Resistant HA
Reference System	Xerolyt Extra polymer + open junction + Argenthal silver trap
Solution Ground SG	Platinum, also measures ORP
Temperature Sensor	Digital signal (ISM built-in)
Electrode Length	425mm
Shaft Material	Glass, 12mm diameter
Process Connection	Pg 13.5
Cable Connector	K8S (ISM digital)
Explosion-proof	ATEX/IECEx/FM/PED/CE
ISM Functions	Plug and Measure, DLI, Adaptive Calibration, Self-diagnostics, EDS

Related Products (ordered separately):

Transmitters: Mettler Toledo M300 ISM, M400 ISM, M700, M800 and other ISM-capable transmitters
Cables: AK9 series K8S cables, e.g., AK9/1m (59902167), AK9/3m (59902193), AK9/5m (59902213), AK9/10m (59902230), AK9/20m (52300204)
Mounting Wells/Brackets: InFit series mounting wells (e.g., InFit 761e/762e), immersion brackets, flow assemblies
Calibration Buffers: Mettler Toledo standard buffers (pH 4.01, 7.00, 9.21 etc.)
Storage Cap: moisturized storage cap
Cleaning Device: EasyClean series automatic cleaning systems

Official Documentation Reference:

Datasheet pH-Electrode InPro4260 for Demanding Process Conditions
InPro4260(i) / InPro4281i Technical Data
ISM (Intelligent Sensor Management) Product Documentation
ATEX Certificate: pH Sensor InPro 2XXX, InPro 3XXX, InPro 4XXX, InPro X1

6. Why Choose Us

Professional Procurement Channel, Quality Guaranteed — All Mettler Toledo products obtained through professional procurement channels, ensuring genuine Mettler Toledo original products with product identification, calibration certificate and quality documents, 12-month quality warranty. Appearance inspection, model confirmation, order number verification, K8S connector check and packaging check performed before shipment, ensuring delivered products intact and model-accurate.
Worldwide Delivery, Professional Instrument Logistics — Supports DHL, FedEx, UPS and other international couriers, global delivery available. Precision analytical instruments use shock-proof moisture-proof anti-static professional packaging, ensuring safe transport of fragile components such as pH glass membranes. Expedited logistics and customs clearance services available per project requirements, delivery to 200+ countries worldwide.
Professional Technical Support, Full-process Service from Selection to Calibration — Provides pH electrode selection consultation (confirming measuring range, temperature/pressure, medium characteristics, installation method, reference system matching, SG and explosion-proof requirements, analog vs ISM digital selection), transmitter and cable matching (M300 ISM/M400 ISM/M700/M800 transmitters, AK9 series K8S cables), ISM function configuration guidance (Plug and Measure, DLI lifetime indicator, adaptive calibration timer setup), calibration support (buffer selection, two-point calibration, pre-calibration process), fault diagnosis (reading abnormality/drift/calibration failure/ISM diagnostic alarm cause analysis) and lifetime assessment, helping users correctly select, install and maintain.
Flexible Procurement, Instrument Spare Parts Packages and Framework Agreements — Supports single electrode procurement and bulk project orders, tiered pricing discounts with quantity. Can provide liquid analysis instrument spare parts packages for chemical/petrochemical/pharmaceutical/water treatment/power industries (pH electrode + ORP electrode + conductivity electrode + dissolved oxygen electrode + transmitter + cable + calibration solution combination) and annual spare parts framework agreements, helping users optimize spare parts inventory and procurement cost.
Pre-shipment Verification, Test Report Available — Appearance inspection, packaging verification, model confirmation, order number check performed before shipment; electrode internal resistance test, glass membrane integrity check, ISM chip communication test and calibration data reading report available if necessary, ensuring delivered electrode model-accurate, in good condition, performance-qualified, ISM functions normal.

7. Frequently Asked Questions (FAQ)

Q1: What is InPro4260i/SG/425? What is the difference from InPro4800/SG? What does "i" mean?

A: The InPro4260i/SG/425 (Order No. 52005407) is an ISM digital in-line combination pH/ORP electrode from Mettler Toledo's InPro4260(i) series, specifically designed for highly demanding chemical applications, with built-in temperature sensor and platinum Solution Ground (SG), supporting ISM Intelligent Sensor Management.

Basic Information:

Brand: Mettler Toledo (Switzerland)
Model: InPro4260i/SG/425
Order No.: 52005407
Series: InPro4260(i)
Type: ISM digital in-line combination pH/ORP electrode
pH Range: 0-14
Temperature Range: 0 to 130°C
Pressure Range: 0 to 15bar@25°C, 0 to 7bar@130°C
Length: 425mm
Connector: K8S (digital)

What does "i" mean?

i = ISM (Intelligent Sensor Management), indicating this is a digital electrode, different from analog electrodes without "i".

Digital electrodes with "i" have integrated ADC and digital communication chip inside. pH signals, temperature signals, and diagnostic information are all digitized and transmitted through K8S cable to ISM transmitter. Analog electrodes without "i" directly output pH millivolt analog signal and PT100/PT1000 temperature signal, transmitted through VP6 cable.

Difference from InPro4800/SG:

表格

Comparison	InPro4260i/SG/425 (this product)	InPro4800/SG/225/PT1000
Signal Type	ISM Digital	Analog
Cable Connector	K8S	VP6
Temperature Sensor	Digital signal (ISM built-in)	PT1000 (analog RTD)
Reference Electrolyte	Xerolyt Extra polymer (solid, patented)	Gel electrolyte
Junction	Open junction (no diaphragm, no clogging)	PTFE annular diaphragm
Silver Trap	Argenthal silver-ion trap	No (standard Ag/AgCl double chamber)
Plug and Measure	Yes	No
Dynamic Lifetime Indicator DLI	Yes	No
Adaptive Calibration Timer	Yes	No
Electronic Data Sheet EDS	Yes	No
pH Glass Membrane	HA glass membrane	HA glass membrane
Solution Ground SG	Platinum, also measures ORP	Platinum auxiliary, also measures ORP
Temperature Range	0 to 130°C	-5 to 130°C
Pressure Range	0 to 15bar@25°C	0 to 12bar@130°C
Shaft	Glass, 12mm diameter	Glass, approx. 12mm diameter
Process Connection	Pg13.5	Pg13.5
Explosion-proof	ATEX/IECEx/FM/PED/CE	ATEX/IECEx/FM/PED/CE
Positioning	Highly demanding chemical, flagship digital	Harsh conditions general purpose, analog
Price	Higher	Medium

Simply put: The InPro4260i is a digital ISM electrode with more powerful functions (Plug and Measure, lifetime prediction, intelligent diagnostics), more advanced reference system (Xerolyt Extra polymer + open junction + Argenthal silver trap, anti-fouling anti-poisoning longer lifetime), suitable for highly demanding chemical applications and users pursuing predictive maintenance; The InPro4800 is an analog electrode with good cost-effectiveness, suitable for users with existing analog transmitter systems or limited budgets.

Q2: How to choose between ISM digital and analog? Are K8S and VP6 connectors interchangeable? What transmitters and cables are needed?

A: The choice between ISM digital and analog depends on your existing system, budget, and maintenance needs. K8S and VP6 connectors are NOT interchangeable.

ISM Digital vs Analog Selection Advice:

表格

Choose ISM Digital (InPro4260i) when	Choose Analog (InPro4260/InPro4800) when
New system, pursuing high reliability and predictive maintenance	Existing Mettler Toledo analog transmitter system (M300/M400 analog)
Need Plug and Measure, reduce field calibration and downtime	Limited budget, pursuing cost-effectiveness
Strong EMI environment (near inverters, motors)	Simple application, few measuring points, low maintenance frequency
Need electrode lifetime prediction and intelligent diagnostics	Existing VP6 cable wiring, do not want to rewire
Need digital documentation (GMP/ISO traceability)	Third-party transmitter/PLC analog pH card system
Sensor to transmitter distance far (>30m)	Short distance (<30m), low interference
Multi-sensor system, unified management	Single point, simple monitoring

Are K8S and VP6 connectors interchangeable?

No. K8S and VP6 are two completely different connectors:

表格

Comparison	K8S (for ISM digital)	VP6 (for analog)
Applicable Electrodes	ISM digital electrodes (with i)	Analog electrodes (without i)
Signal Type	Digital signal	Analog signal (pH mV + PT100/PT1000)
Pin Definition	Digital communication dedicated	6-core analog (black/red/grey/blue/white/green)
Cable	AK9 series K8S cable	VP6-ST/VP6-HT series cable
Protection Rating	IP68	IP68
Interchangeability	Only K8S cable and ISM transmitter	Only VP6 cable and analog transmitter

If you buy an ISM digital electrode (K8S connector), you must use AK9 series K8S cable and ISM-capable transmitter; VP6 cable cannot be used. And vice versa.

What transmitters are needed?

The ISM digital InPro4260i must be paired with Mettler Toledo ISM-capable transmitters:

M300 ISM series (single/multi-channel, compact)
M400 ISM series (single/multi-channel, standard)
M700 series (multi-parameter transmitter)
M800 series (multi-channel multi-parameter, high-end)
Other Mettler Toledo ISM-capable transmitters

Notes:

Third-party transmitters do not support ISM digital communication, cannot directly connect to InPro4260i
If you use a third-party PLC/DCS system, you can choose a Mettler Toledo ISM transmitter, then output to PLC/DCS via 4-20mA/HART/Modbus/Profibus etc.
Analog transmitters (e.g., M300/M400 analog version) cannot connect to ISM digital electrodes

What cables are needed?

The InPro4260i (K8S connector) uses AK9 series K8S cables:

表格

Model	Order No.	Length
AK9/1m	59902167	1m
AK9/3m	59902193	3m
AK9/5m	59902213	5m
AK9/10m	59902230	10m
AK9/20m	52300204	20m

AK9 cable has K8S plug at one end (to electrode) and open end/pins at the other (to transmitter terminals), standard temperature range -30 to 80°C.

Selection advice:

If it's a new system → choose InPro4260i (ISM digital) + M300/M400 ISM transmitter + AK9 cable, fullest functions, most convenient maintenance
If you already have M300/M400 analog transmitter and VP6 cable → choose analog InPro4260/InPro4800, directly compatible, no need to replace transmitter and cable
If you are unsure about your existing transmitter type → provide the transmitter model, we will help confirm compatible electrode type

Q3: What is the difference between open junction and PTFE diaphragm? What is Xerolyt Extra electrolyte? Does it need refilling?

A: The InPro4260i uses Open Junction + Xerolyt Extra polymer electrolyte, which is a completely different reference system design from the InPro4800's PTFE annular diaphragm + gel electrolyte, each with its own advantages.

Open Junction vs PTFE Diaphragm:

表格

Comparison	Open Junction (InPro4260i, this product)	PTFE Annular Diaphragm (InPro4800)
Structure	Reference electrolyte in direct contact with medium, no diaphragm	PTFE material annular diaphragm, separates reference chamber and medium
Clogging Risk	None (no diaphragm, no clogging problem)	Low (PTFE anti-fouling, but extreme fouling may still clog)
Anti-fouling	Excellent (open type, for high-fouling/suspension/emulsion/protein media)	Strong (PTFE low surface energy, anti-fouling)
Electrolyte Loss	Slow (Xerolyt Extra polymer, solid)	None (gel sealed, no loss)
Response Speed	Good	Good
Suitable Media	High-fouling, suspended solids, emulsion, protein, sulfide, oils	General industrial media, moderate fouling
Maintenance	Maintenance-free, no refilling	Maintenance-free, no refilling
Price	Higher	Medium

Advantages of Open Junction:

Traditional diaphragms (ceramic/PTFE) are easily clogged by contaminants in media with suspended solids, proteins, sulfides, oils, high viscosity, leading to unstable reference potential, slow response, inaccurate measurement
Open junction has no diaphragm; reference electrolyte (Xerolyt Extra polymer) directly contacts the medium, fundamentally eliminating clogging
Especially suitable for chemical reaction solutions, wastewater, pulp, emulsions, protein solutions, sulfide-containing media and other high-fouling conditions
Xerolyt Extra is solid polymer, does not rapidly lose like liquid electrolyte, long lifetime

What is Xerolyt Extra electrolyte?

Xerolyt Extra is Mettler Toledo's patented solid polymer reference electrolyte, a special polymer material that replaces traditional liquid KCl electrolyte and gel electrolyte.

Xerolyt Extra features and advantages:

Insensitive to flow variations: Traditional liquid/gel electrolytes experience potential fluctuations (flow potential) at the junction when medium flow rate changes, causing unstable measurement. Xerolyt Extra polymer electrolyte is insensitive to flow variations, measuring more stably in pipelines and open channels with fluctuating flow rates.
Especially suitable for low ionic strength media: In pure water, low ionic strength solutions, traditional liquid electrolyte junction potential is unstable with large measurement errors. Xerolyt Extra maintains stable reference potential in low ionic strength media, suitable for pure water, boiler feedwater, ultrapure water and other low ionic media.
Organic solvent resistant: Xerolyt Extra polymer does not dissolve or deteriorate in organic solvents (alcohols, ketones, esters, hydrocarbons, etc.), reference potential stable, long lifetime in chemical processes with organic solvents. Traditional liquid KCl electrolyte may be extracted/diluted in organic solvents, causing reference system failure.
Insensitive to anionic salts: Insensitive to nitrate, sulfate, carbonate and other anionic salts, stable reference potential in media containing these ions, no significant junction potential changes.
Strong acid and alkali resistant: Good chemical stability in strong acid and alkali media, not damaged by acids and alkalis, extends electrode lifetime.
Solid maintenance-free: Xerolyt Extra is solid polymer, sealed in reference chamber, no electrolyte refilling needed, completely maintenance-free, no liquid electrolyte leakage, frequent refilling, air bubble introduction from refilling etc.
Patented product: Xerolyt Extra is Mettler Toledo patented technology, only used in high-end series such as InPro4260(i)/InPro4281i.

Does it need refilling?

No. The Xerolyt Extra in the InPro4260i is solid polymer electrolyte, sealed inside the electrode; users cannot and do not need to refill. Replace the electrode directly when lifetime is reached.

Difference from gel electrolyte:

表格

Comparison	Xerolyt Extra polymer (InPro4260i)	Gel electrolyte (InPro4800)
State	Solid polymer	Semi-solid gel
Flowability	None (completely solid)	Very low (semi-solid)
Organic solvent resistance	Excellent	Fair (some organic solvents may affect)
Low ionic strength	Excellent	Good
Flow sensitivity	Very low	Low
Lifetime	Longer (patented formulation)	Medium
Refilling	Not needed	Not needed
Price	Higher	Medium

Simply put: Open junction + Xerolyt Extra polymer is the core advantage of the InPro4260i, fundamentally solving diaphragm clogging, with longer lifetime and more stable measurement in harsh media such as high-fouling, low ionic, organic solvent, strong acid and alkali, completely maintenance-free no refilling — the ideal choice for highly demanding chemical applications.

Q4: How to use ISM Plug and Measure? What are Dynamic Lifetime Indicator and Adaptive Calibration?

A: ISM (Intelligent Sensor Management) is Mettler Toledo's digital sensor technology. As an ISM electrode, the InPro4260i provides Plug and Measure, Dynamic Lifetime Indicator, Adaptive Calibration Timer, advanced self-diagnostics, Electronic Data Sheet and other functions.

1. How to use Plug and Measure?

Plug and Measure is one of the most practical ISM functions, allowing you to pre-calibrate electrodes in a safe area and then directly install and use them on site.

Operation process:

Pre-calibrate in safe area: Take the new or 待校准 electrode to a safe area such as laboratory, maintenance room, connect to ISM transmitter or portable ISM calibrator (e.g., Mettler Toledo M300 portable)
Perform two-point calibration: Use standard buffers (pH 4.01 and 7.00, or 7.00 and 9.21) for two-point calibration, same method as ordinary pH electrode calibration
Calibration data automatically stored: After calibration, calibration data (zero point, slope, calibration date, buffer lot number, etc.) is automatically written and stored in the electrode's built-in ISM chip
Field installation: Take the pre-calibrated electrode to the site, install at the measuring point (reactor, pipeline, open channel, etc.), connect K8S cable to field ISM transmitter
Plug and Measure: The transmitter automatically recognizes the electrode, reads calibration data stored in the electrode, immediately starts normal measurement, no need to recalibrate on site

Advantages of Plug and Measure:

Safety: Avoids calibration operations in hazardous environments (high temperature, high pressure, toxic, explosion-proof areas, high altitude), protects maintenance personnel safety
Fast: Electrode replacement in just minutes, no waiting for field calibration, significantly reduces downtime
Accurate: Calibration in good laboratory/maintenance room environment is more accurate than field harsh environments (temperature fluctuations, medium interference, limited space)
Traceable: Calibration data stored in electrode chip, readable anytime, meeting GMP/ISO quality management requirements

Notes:

Plug and Measure requires ISM transmitter support (M300 ISM/M400 ISM/M700/M800 etc.)
Pre-calibrated electrodes should be installed and used within a reasonable time (recommended within weeks, avoid long-term storage causing performance changes)
After installation, it is recommended to verify the measurement value with process medium to ensure reasonableness

2. What is Dynamic Lifetime Indicator (DLI)?

The Dynamic Lifetime Indicator is ISM's predictive maintenance function, real-time monitoring electrode aging status and predicting remaining lifetime.

Working principle:

The ISM electrode continuously monitors multiple parameters: glass membrane impedance, reference system status, calibration history (zero/slope change trend), operating temperature, pH range, medium conditions, etc.
Based on these actual usage data, the ISM algorithm dynamically calculates electrode aging degree and remaining service lifetime
Displays electrode remaining lifetime graphically on the transmitter screen (e.g., percentage, progress bar, remaining days/weeks)

DLI advantages:

Predictive maintenance: Early warning before electrode failure, schedule planned replacement, avoid unplanned downtime
Maximize electrode lifetime: Judge lifetime based on actual usage conditions rather than fixed-time replacement, replace only when truly needed, reduce spare parts cost
Reduce unexpected failures: Avoid measurement interruption, product quality issues, environmental exceedance caused by sudden electrode failure
Maintenance planning optimization: Based on DLI status of multiple electrodes, uniformly arrange maintenance plans, optimize maintenance resources

DLI display example: Transmitter screen shows "Electrode remaining lifetime: 65%", "Recommended replacement time: approx. 8 weeks", and sends warning alarm when remaining lifetime below threshold (e.g., 10%).

3. What is Adaptive Calibration Timer?

The Adaptive Calibration Timer intelligently determines next calibration due time, rather than fixed-period calibration.

Working principle:

Traditional method: Fixed calibration period (e.g., monthly, quarterly), calibrate on time regardless of actual electrode status
ISM adaptive calibration: Based on actual electrode usage (temperature, pH, medium, DLI lifetime status, performance change trend since last calibration), intelligently calculates when electrode performance will decline to the point needing calibration
When electrode performance is stable and conditions are good, automatically extends calibration interval
When electrode aging accelerates or conditions are harsh, automatically shortens calibration interval

Adaptive calibration advantages:

Reduce unnecessary calibration: Extend calibration interval when electrode status good, reduce maintenance workload and downtime
Ensure measurement quality: Timely remind calibration when electrode performance declines, avoid measurement out-of-tolerance
Reduce calibration cost: Reduce buffer consumption, maintenance labor, downtime
Data-driven: Based on actual data rather than empirical judgment, more scientific and reasonable

4. Other ISM functions:

Advanced sensor self-diagnostics: Continuously monitors glass membrane impedance (judges glass membrane aging/damage), reference system impedance (judges reference poisoning/diaphragm status), solution ground status, temperature sensor status, cable connection status, etc., timely detects faults and alarms
Electronic Data Sheet (EDS): Electrode built-in chip stores all information: model, order number, serial number, production date, calibration history (zero/slope/date/buffer for each calibration), maintenance records, diagnostic data, operating hours, etc., enabling digital documentation management, meeting GMP/ISO/FDA traceability requirements, no manual recording needed
100% signal integrity: Digital signal transmission, not affected by electromagnetic interference, signal attenuation, ground loops, maintains high accuracy even over long distances

Simply put: ISM technology transforms pH electrodes from "passive measurement tools" into "intelligent sensors". Plug and Measure makes maintenance safer and faster, Dynamic Lifetime Indicator enables predictive maintenance, Adaptive Calibration reduces unnecessary maintenance, Electronic Data Sheet meets traceability requirements — overall reducing electrode total lifecycle cost, the development trend for highly demanding industrial applications.

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

A: This model is currently in Order Available status. The InPro4260i series is Mettler Toledo's high-end ISM digital pH electrode for highly demanding chemical applications; specific inventory fluctuates with market.

Lead time: Standard lead time 4-8 weeks (ordered through professional procurement channels or allocated from global inventory). ISM digital electrodes have relatively less stock than analog ones. Some common lengths (120mm/225mm) may be in stock; the 425mm long version has relatively less stock, specific subject to formal quotation confirmation.
Price: Specific price subject to our formal quotation, depends on purchase quantity, supply channel, whether includes calibration certificate and technical service. As a high-end ISM digital electrode, the InPro4260i is priced higher than analog electrodes; bulk procurement enjoys tiered discounts.
Expedited service: For urgent needs (e.g., process fault emergency repair, environmental discharge online monitoring emergency replacement, project commissioning emergency), we can try to coordinate global stock inventory or expedited ordering, specific please contact sales team.
Please indicate required quantity, application industry, measured medium, temperature/pressure, compatible transmitter model, explosion-proof requirements, desired delivery time and destination when inquiring; we will coordinate fastest delivery solution and optimal price.
If you need to purchase matching Mettler Toledo ISM transmitters (M300 ISM/M400 ISM/M700/M800), AK9 series K8S cables (1m/3m/5m/10m/20m), mounting wells (InFit series), calibration buffers, storage caps and other accessories simultaneously, we can provide complete ISM digital pH/ORP measurement system combined quotation with more favorable prices.

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