pH Sensor - Suitable for NH₃/brine leakage detection

Technical data: HBPH-MK2-LT

HBPH-MK2-LT is a pH sensor designed for the extreme requirements of industrial refrigeration. It is used to measure the pH value of brine in case of an ammonia leak in a heat exchanger. Brine has a pH value of 7, and even for small leaks, the pH will rise to 9-10. The sensor is designed with differential measurement technology that ensures a minimum lifetime of 2 years for the sensor element.

The latest version HBPH-MK2-LT has an improved and protected universal flat-faced glass process electrode specially designed for tough applications.

The HBPH-MK2-LT -sensor can be used together with our “NH3/Brine leakage Display” type HBPH-C1 which is a controller used to calibrate and set up the alarm limit for the HBPH-MK2-LT sensor.

The HBPH-MK2-LT sensor comes with 3-pack salt bridge replacement kit.

HBPH-C1 can be found here.

Product features

  Simple wiring with 2-wire measurement technology.
Measurement range: 0..14 pH - 4...20 mA.
Accurate measurement - Resolution +/-0.01Ph
Differential measurement technology with replaceable salt bridge.

Low maintenance costs.

Designed with "Semi-flush" design so as to minimise the build-up of dirt on the probe.


chiller med pH sensor web.jpg



Connection diagram



Factory Calibration:

A standard factory calibration would guaranty the accuracy of 88% or better (usually in mid 90's) and the offset of 0.85pH of fewer for a brand new sensor.

This means that the sensor have to calibrated if you need a precise and accurate output. If you like to use the sensor for detecting ammonia leakage into fresh water of mixtures between water and ethanol/methanol/glycol a calibration is normally not needed. If you like to use the sensor in other brines with a higher pH value or in NaCl brines, we strongly recommend a calibration. The reason is that an ammonia leakage will not impact the pH value as much in these fluids, because they act as a buffer.

Using 4mA = 0pH and 20mA = 14pH, the worst case scenario (88% accuracy and max allowed offset) may equate to roughly speaking ±1.0 pH assuming no calibration is done at the installation site.



Power supply
Cable4.5 m
Power supply20...28 V DC
Output4...20 mA, not calibrated
Max load450 ohm
Max cable lengthDepends on cable size
Environmental conditions
Ambient temperature-15...+50°C
Liquid temperature-15...+95°C (+5...+203℉)*
Measurement range0...14 pH
Resolution±0.01 pH
Max pressure6.9 bar @ 65°C & 2.75 bar @ 95°C
Protection degreeIP65
FlowrateMax 3.0 m/s
VibrationsIEC 68-2-6 (4g)
Mechanical specifications
Thread connection1" NPT
MaterialRyton, ceramic, titanium, glass, viton
EMC testEN 61000-2
3-pack salt bridge replacement kit HBPH-2W-9-MK2-KIT
Controller for pH Sensor HBPH-C1
Controller for pH Sensor HBPH-C1-ENC

Ordering code

Measurement area pHThread typeOrdering code
0...141" NPTHBPH-2W-9-MK2-LT

3-pack salt bridge replacement kitHBPH-2W-9-MK2-KIT
Controller for pH SensorHBPH-C1
Controller for pH SensorHBPH-C1-ENC


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