pH value: Sensors

Appropriate sensor is fundamental to any measurement setup. Variety of different types and variants are available, depending on the measured quantities, sensor dimensions, as well as usage workflow, environment, and installation method. The vast majority of sensors listed below are just components of a larger measurement setup, and can therefore be satisfactorily used only with a compatible analyzer. Sensors for in-technology measurements should be installed inside our probes, ensuring their fixing and protection, and these connect to a terminal block. Variants for laboratory and portable usage are terminated with the appropriate connector. Sensors generally have the shortest lifetime of the entire setup, due to direct contact with the measured medium.

pH sensors


Glass sensors for measuring pH integrate both the pH electrode and the required reference electrode in one unit.

Individual variants differ depending on the purpose of the sensor, mainly in terms of length, shaping of the active part and method of attachment. Sensor cables for laboratory use are terminated with a connector according to the type of instrument used.

Glass electrodes cannot be used in the presence of fluoride ions. In this case, antimony electrodes (available on request) are used. The alternative designations listed below apply to previously supplied sensors.

TypeSuitable forDimensionsAlternative designation
01-29GInstallation with SPO41, SPO42, SPR42, SVK42, PE G3/4DØ12.2 x 115 mmpH 21PT
01-30GInstallation with SPO41ME, SPR41MEØ12.2 x 115 mmpH 21PTC
01-29GKInstallation with PB42V, PB43V, SPO41K, PE G3/4KØ12.2 x 57 mmpH 21PTK
01-30GKInstallation with SPO41MEK, SPR41MEKØ12.2 x 57 mmpH 21PTCK
521-BNCInstallation with SHI63Ø12.2 x 59 / 117 mm-
PH21SMFD79, MFD80 (with transport cover)-
on requestLaboratory measurements (multiple options)typ. Ø12.2 / Ø18 x 115 mm-

Reference electrodes


For sensors that do not have an integrated reference electrode, separate reference electrodes are required – this is often the case with ion-selective electrodes. Since a pair of separate electrodes is then used, industrial applications will need a suitable probe or flow-through unit that allows at least two sensors to be installed.

Commonly supplied sensors for measuring pH and ORP have the required reference electrodes already integrated, so there is no need to supplement them with additional electrodes.

TypeSuitable forDimensions
RAE111Installation with SPO42, SPR42Ø12.2 x 115 mm
RAE111KInstallation with PB42V, PB43VØ12.2 x 57 mm
on requestLaboratory measurements (multiple options)typ. Ø12.2 (Ø18) x 115 (145) mm

Temperature sensor TTK21


Separate temperature sensors are primarily used to compensate for the temperature dependence of sensors not equipped with built-in temperature sensing. This improves the accuracy of the measurement. The measured temperature reading is usually also available as an output for the user.

TypeSuitable forDimensionsCase material
TTK21PLIndustrial probesØ14 x 115 mmStainless steel
TTK21PMIndustrial probesØ14 x 94 mmStainless steel
TTK21PSIndustrial probesØ14 x 60 mmStainless steel
TTK21PXIndustrial probesØ10 x 40 mmStainless steel
TTK21LLaboratory useØ12 (Ø14.5) x 115 (145) mmGlass
Sensor typeNTC thermistor
Measurement range-5 to +105 °C
CompatibilityMFD79, MFD80, MFD88
Resistance at 25 °C3000 Ω

Temperature sensors TNiK21, TNiK115


Separate temperature sensors with nickel-type sensing element are only compatible with some older types of our devices. Pay attention to the data in the table.

TypeSuitable forDimensionsCase material
TNiK21Industrial probessimilar to TTK21 (multiple options)Stainless steel
TNiK115Laboratory useØ12 (Ø14.5) x 115 (145) mmGlass
Sensor typeNickel
Measurement range-5 to +105 °C
CompatibilityMFD77, MPH77, MPI77, MFD77PHK, MSV77 (MPH66, MFD66, MFD66PHK, MPI66, MPH66L, MPH44P, MPH44L, MPH44LN, MPH44LT, MPH44, MPH44E)
Resistance at 0 °C2000 Ω