Glass-lined pH Probes

Long-lasting and low-maintenance

pH probe type 40

The pH sensor type 40 changes the nature of pH measurement by eliminating the need for internal electrolyte solutions and reference junctions. This design virtually eliminates the problems caused by ageing and pollution of the reference sensor. This pH-measurement principle is called relative pH-measurement.

The probes design and the rugged Pfaudler Glasteel™ surface allows them to be directly installed into the process (product flow), thus detecting the pH immediately and directly, without a protective cage.

The pH probe type 40 is available in a rod and a ring design. Alternatively, the smaller pH probe type 18 can be used.


Find more probes in the Pfaudler Product Selection Guide

Technical data – Product overview

Type pH 40 / Rod & Ring
Measuring range +3 to +12 pH *
Operating temp. 0 to +140 °C ***
Operating pressure -1 to +40 bar ***
Ex. protection II 1/2 G EEx ia IIB T6 or
II 2G EEx ia IIC T6
Dimensions (mm) Rod probe
L = 300 – 3,200 **
DN = 50 – 200 **
Ring probe:
DN50 / DN80 **
Product benefits – Heavy-Duty Design
– Highly resistant glass layer
– Maintenance-free
– No diaphragm
– No ageing / No drift
– No electrolyte required
– CIP/SIP-compliant
– Self-cleaning

* Depends on temperature
** Other dimensions on request
*** Higher pressure/temperature on request