Siemens SIPROCESS GA700, Operating Instructions Manual, Page: 185 / 224

8.3.4 Reference gas from the gas cylinder
For a sufficient measuring ability, the reference gas pressure must be at least 2 000 hPa +/-
150 hPa above the sample gas pressure.
1. Use a reference gas line with the following characteristics at measuring spans of < 2%:
– Small cross-section, e.g., pipe diameter 1/16"
– 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/
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.
8.3.5 Checking the reference gas flow
1. Close the sample gas inlet.
2. Lay a hose with an internal diameter of 4 mm from the sample gas outlet into a beaker filled
with water.
3. Apply reference gas to the analyzer module.
The reference gas must exit slowly with 1 to 2 bubbles per second through the water filling (at
versions with flow-type compensation circuit, 2 to 4 bubbles per second). The reference gas
flow rate is then sufficient.
8.3.6 Sample gas inlet conditions
Prevent condensation of the sample gas in the gas path by using suitable measures.
Commissioning
8.3 OXYMAT 7
Field device
Operating Instructions, 05/2015, A5E35640463-02
73