Samson Media 7, Mounting And Operating Instructions

Page: 62 / 96

62 EB 9510 EN
Operation of Media 7 Differential Pressure Meter
The user level must be set to 'Specialist' for the zero calibration (see section 8.1.3).
When gas column correction is selected, you need to take into account that the gas columns
in the measuring lines reduce the differential pressure because they oppose each other.
When the pressures are identical (∆p = 0 mbar) a negative value appears on the display for
the content. An output signal lower than 4 mA is indicated. In this case, readjust zero as de
-
scribed below so that the display reads 0 % at ∆p = 0 mbar. The output signal will change
but remains below 4 mA due to the adjusted gas column correction.
Zero calibration when the tank is empty
1. Press key (in start screen) to go to the main menu.
2. Select Start-up (1) with or
key and confirm with key.
3. Select Zero (1.5) with or key and confirm with key.
The current values for differential pressure, zero, and maximum differential pressure
(Δp
100
) are displayed.
4. Press key to set zero.
Zero calibration when the tank is filled
Î
To equalize the pressures, isolate the measuring lines to the tank and connect them over a
bypass. When a SAMSON valve block is used, proceed as follows (see Fig. 5
on
page 23):
1. Close shut-off valve (+) and shut-off valve (–).
2. Open the equalizing valve.
Î
The valve block is now in the test position.
3. Perform zero calibration (see Zero calibration when the tank is empty).
Î
Place the valve block or equalizing valve back into the operating position:
4. Open the shut-off valve in the low-pressure line.
5.
Close the equalizing valve.
6. Open the shut-off valve in the high-pressure line.
Note
Note