Analytical sensors with a transmitter in the sensor head

By W Babel, Krohne


Published in:

Electricity+Control, July 2014 (pages 26-27)

Enquiries: Krohne South Africa. Tel. 011 314 1391 or email


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Measuring pH value is the most important analytical measurement when it comes to determining the quality and controlling processes. Approximately 50 % of all measuring points in analytical measuring are pH measurements. Every year more than 1 million pH sensors are manufactured for process instrumentation.

With so many measuring points, it pays to take a look at the factors influencing the safety of a pH measurement and what actions manufacturers of analytical measuring technology have taken to reduce risks:


o Safety factor 1: Signal transmission

o Safety factor 2: Calibration

o Safety factor 3: Transmitter


Little about these safety factors changed with the birth of the digital pH measurement sensor in 2006. The idea of inductive data and energy transfer between sensor head and data coupling solves the problem of high resistance. It was only in the years that followed that the revolutionary options of digital analytical sensors in terms of offline calibration were recognised.

This meant that the lifetime of the pH measurement sensors was extended many times and that by calibrating in the laboratory the error risk during calibration was reduced. Thanks to digital analytical sensor technology, starting in 2006 many customers had the increasing desire to omit the transmitter and integrate the entire electronics in the sensor head of the electrode. For economic and technological reasons this remained a wish – until today.


Take note

  • Digital analytical sensors with integrated transmitter technology make external transmitters superfluous.
  • Integrated transmitter technology is designing sources of error out of modern sensors.
  • About half of all analytical measurement is pH measurement.