Siemens ULTRAMAT 23 - Area of Application

Supplement 1 for Operating Instructions C79000-G52xx-C216-03
2 A5E02769382-03, 03/2012
Product information / technical updates
Description
Area of application
This device is designed to measure H
2
S.
Application areas include
● Biogas plants
● Sewage plants
● Drinking water treatment
● Feeding of biogas into the natural gas grid
Function
Measuring principle
The hydrogen sulfide enters through the diffusion barrier (gas diaphragm) into the sensor and is oxidized at the working
electrode. A reaction, the reduction of atmospheric oxygen, takes place on the counter electrode. A current which is directly
proportional to gas concentration results on the connector pins due to the electron transfer.
+6
+6
+
6
+
6
+
62
:RUNLQJHOHFWURGH
&RXQWHUHOHFWURGH
5HIHUHQFHHOHFWURGH
&RQQHFWLRQSLQV
*DVGLDSKUDJP
HOHFWURO\WH
Figure 1 Operating principle of the H
2
S sensor
Calibration of the measured value drift
The deflection signal of the sensor is subject to drift. This drift can be detected only through regular review and corrected as
needed. This involves using a calibration gas with a defined concentration of hydrogen sulfide. We recommend monthly
calibration (re-adjustment) with one of the following calibration gases (depending on the measuring range) to keep potential
measurement uncertainty within strict limits:
● 4 ... 40 vpm H
2
S
● 2 500 ... 3 000 vpm H
2
S