7
Installation
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gas-lab
Q1
As an option, a bypass for the process gas flow may be installed to speed up
the sampling. With a flow meter and a needle valve, it is possible to adjust the
gas flow in the vent gas line. The gas flow in the bypass can be separately
measured and adjusted. The mounting plate must be earthed at the installation
site.
7.3.2 Installation site
The installation site of the sensor system has to offer protection against direct
solar radiation and rain and has to comply with protection class IP 54 of the
sensor system.
An ambient temperature from 5 to 40°C is permissible; a temperature drop to
0°C or a rise to 45
°C will result in increasing measurement errors, but it won’t
damage the device.
The ex-protection class of the sensor system is: II 2G EEx d IIB T4. The Q1
evaluation computer, however, must be installed in a non-hazardous room.
For official approved applications the installaion side must according to local
metrological approval. For example German PTB-A 7.62. The room temperature
has to be monitored for example in the limits from 5 °C to 40 °C.
7.3.3 Gas injection line
The pipes for the process and calibration gases (methane) are connected to the
respective low-pressure regulators (Elster M2R); usually these are stainless
steel pipes with a 6-mm diameter. The inlet pressure must range between 1 to 5
bars overpressure. The outlet pressure has been preset by the manufacturer,
amounts to about 80 mbars and is indicated at the pressure gauge. Each low-
pressure regulator is equipped with a safety shut-off valve that is protected by a
safety relief valve. The regulators have a joint venting pipe, which must be
conducted to the outside separately from the other vent gas pipes by means of a
stainless steel pipe with a diameter of 10 mm.
The process gas and calibration gas flows can be shut off on the mounting plate
by means of valves. When gas is injected, these valves must be closed at first
and then opened very slowly to prevent the safety shut off valve from tripping
and the pressure gauge from getting overloaded. Should the safety shut-off
valve have been triggered nevertheless, it can be released by strongly pulling at
the release button.