Introduction Of Reference Gas; Reference Gas From The Gas Cylinder - Siemens SIPROCESS GA700 Operating Instructions Manual

Information on interference gas correction is available in the following operating manuals:
● Operating with the Local User Interface Table A-3 References 1 - Operating Manuals LUI
(Page 141)
● Operation with SIMATIC PDM Table A-4 References 2 - Operating Manuals PDM
(Page 141)
See also
References (Page 141)
9.3.4

Introduction of reference gas

Note
Composition of the reference gas
Using an unsuitable reference gas can cause the reference gas throttle (capillary tube) to be
closed. The device is then no longer capable of measuring.
THerefore always use dust-free reference gas as far as possible (particle size < 10 μm).
● Always introduce the reference gas before beginning the measurements.
● In the case of temporary interruption of the measurements, reference gas should also
always flow. This prevents the sample gas remaining in the measuring chamber from
diffusing to the microflow sensors and possibly destroying them.
9.3.5

Reference gas from the gas cylinder

The reference gas pressure must be 2 000 hPa above the sample gas pressure for sufficient
measuring ability.
1. Use a reference gas line with the following characteristics at measuring spans of < 2%
oxygen:
– Small cross-section, e.g. pipe diameter 2 mm
– Made of metal, e.g., stainless steel
2. Flush the reference gas line thoroughly with reference gas before commissioning.
3. Check the reference gas line for leaks to avoid unnecessary losses:
– Close the valve at the gas cylinder.
– If the pressure display on the pressure reducer does not drop by more than 1 000 hPa/
Rack-mounted device
Operating Instructions, 05/2015, A5E31874006-03
min, the gas connection is sufficiently tight.
In the case of two-stage pressure reducers, the inlet pressure must not drop by more
than 1 000 hPa/min.
Commissioning
9.3 OXYMAT 7
107