Siemens 7MB3000 Series Operating Instructions Manual page 93

Note
Shutting off the sample gas inlet and outlet
If you shut off the sample gas inlet and outlet, make sure that the reference gas can escape, for
example, by a 2-way valve at the sample gas outlet. Alternatively, the connection of an
overpressure valve is possible. The trigger pressure must then lie approx. 0.1 MPa above the
selected sample gas pressure.
Otherwise, excessive reference gas pressure can build up in the analyzer unit. The result could
be destruction of the internal pressure sensor or its connection to the analyzer unit.
Do not switch off the reference gas! Corrosive sample gases can destroy the microflow sensor.
Ensure that the reference gas flowing via the sample gas outlet is discharged in an
environmentally friendly manner.
Note
Avoiding pressure fluctuations in the sample gas outlet
When the sample gas is conducted into a collective exhaust gas line, the exhaust gas line must
be free of "rapid" pressure fluctuations. If such pressure fluctuations are present, implement the
following remedial measures:
• Install a special exhaust line.
• Alternatively: Install a damping vessel (> 1 l) with a downstream restrictor between the
device and the exhaust line (pneumatic low pass).
• To avoid steam condensation in the exhaust gas line, lay the exhaust gas line as vertically as
possible.
Note
Unstable measured value display due to pressure surges
Pressure surges can result in unstable measured value displays when the sample gas flow is
superimposed by fast pressure fluctuations or a sample gas pump delivers sample gas into the
device. To protect the device from pressure surges, we recommend that:
• Install the supplied sample gas restrictors into the gas path.
• Use a pneumatic low-pass filter (restrictor and damping vessel), if necessary.
Wall-mounted device
Operating Instructions, 07/2023, A5E31930403-AB
Connecting the device
8.1 Gas connections
93