Instruction Manual Dräger P7-TDX
18
The actual operating pressure must be set as the nominal
operating pressure for operating pressures > 30 hPa (mbar);
otherwise the operating pressure must be set to 23.00 hPa
(mbar).
Accept operating pressure and establish connection to the
system.
The current pressure is shown.
Start measurement.
Now, purging is conducted for the connecting line and the
measurement system for 40 seconds, to prevent falsifications
of the measurement result. The gas is released from the gas
connection between the pressure inlets for the mbar and bar
sensors. At the same time, the flow rate is < 5 l/h. The stabili-
zation phase automatically begins after purging.
9.3.3 Stabilization
The stabilization of the gas pressure takes approx. 2 to 10
min. The current pressure in the gas pipeline to be tested, the
already elapsed time of the stabilization period and the pres-
sure drop up to this point (negative values mean that the
pressure in the gas pipeline has increased, e.g. due to tem-
perature influence) are shown. If stabilization has been
reached or if 10 minutes have passed, the stabilization phase
is automatically terminated and indicated acoustically.
The measuring system gives the instruction to close the gas
supply for the gas pipeline to be tested (e.g. main valve di-
rectly behind the gas meter) and provides information about
the current pressure in the gas pipeline to be tested and the
pressure drop up to this point. If the gas supply is closed and
the gas pipeline to be tested has a leak, the measuring de-
vice will detect a pressure drop. If the pressure drop is great-
er than 0.4 hPa (mbar), the leak measurement is started au-
tomatically, provided that automatic start is activated.
