Checking Measuring Range (Span) - Samson Media 6 Mounting And Operating Instructions

Media 6 with LED
According to the test arrangement, a cur-
rent signal of 4 mA must be supplied at con-
nector A or at the TEST connection at a dif-
ferential pressure of ∆p = 0 mbar.
Correction when the tank is filled
1. Close the shut-off valve in the high-
pressure line.
2. Open the equalizing valve or bypass in
the valve block.
3. Close the shut-off valve in the low-
pressure line.
The valve block is in test position!
Write protection: turn switch 4 OFF.
Press and hold down key. LED starts to
flash rapidly. Current signal I indicates
the present mA value.
Press key. Zero is adjusted.
Current signal I = 4 mA corresponding
to the liquid level at 0 mbar differential
pressure. For gas column correction,
the following applies: I < 4 mA.
(See also the note on gas column correction
on page 17.)
The LED flashes continuously for ~ 2 s.
Release key.
Return valve block or equalizing valve to
operating position:
1. Open the shut-off valve in the low-
pressure line.
2. Close the equalizing valve.
3. Open the shut-off valve in the high-
pressure line, the LED goes off.
Activate the write protection: turn switch
4 ON.

6.4 Checking measuring range (span)

A basic calibration with a linear charac-
teristic based on the upper range value of
the dp cell has been made at the factory (de-
fault). Using the entered tank and gas data,
the instrument adopts the tank characteristic
and calculates values proportional to the
tank capacity to indicate and issue the out-
put signal from 4 to 20 mA using the gas
data for the gas selected.
In exactly the same way, the differential
pressure meter calculates the maximum
possible differential pressure ∆p 100 in
mbar for each type of gas and the predeter-
mined reference height (total height or
gauge pipe). The output signal of 20 mA
must correspond to ∆p 100.
Connect the differential pressure meter as
shown in Fig. 9 to check the measuring range.
Note!
It is useful to activate the gas with the lar-
gest density to adjust the span. The values
for gases with smaller densities are also cali-
brated with this calibration procedure.
Important!
To calibrate the gas currently available, its
indicated value must be at least 85 % of the
adjusted upper range value of ∆p 100.
Note!
The span calibration is protected (switch 3)
to prevent the span from being adjusted by
incorrect operation.
Setting
19
EB 9527-1 EN