H82.0.02.6C-05
Operating Manual GMH 5150
page 10 of 22
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7 Remarks to Special Features
7.1 Different Pressure Units
Depending on the connected sensors different units can be selected via menu (Unit). The measuring range
of the sensors may restrict the choice!
User-Unit
For pressure units, which are not covered by the ones printed on the display, there can be done a manual
setting for a “user-defined” unit.
Example:
To enable a GMSD 2 BR - K51 ( -1000
… 2000 mbar) to display the unit kg/cm
2
, following settings (bold)
have to be entered:
kg/cm
2
Torr
atm
at
bASE user:
bar
mbar
bar
bar
DP user:
.0000
.0000
.0000
.0000
FACt user:
1.0197
.7433
0.9869 1.0197
7.2 Different kinds of measuring
Three different kinds of pressure measuring are supported. Two of them (P.dEt and FASt) are working with
high measuring frequency of more than 1000 measurings per second.
7.2.1 Standard measuring (slow)
Measuring rate 4 Hz, averaging and filter functions are active.
Application: Measuring of slowly changing or static pressures, e.g. measuring of leakproofness,
atmospheric pressure...
Highest accuracy, high noise immunity, low power consumption.
7.2.2 Peak detection (Peak detection)
Measuring rate >1000 Hz, the value is displayed unfiltered.
Application with logger function: Measuring of short pressure peaks or fast changing pressures with
a resolution of <1 ms. The cyclic logger function records the arithmetic mean value, the highest and
the lowest peak of the referring time interval.
Attention: higher power consumption, measuring is sensitive to noise (EMI, ...).
Measuring is sensitive to noise (EMI, ...)
and higher power consumption.
7.2.3 Fast filtered measuring (fast)
Measuring rate >1000 Hz, but the value is filtered (higher noise immunity than P.dEt, small peaks
will be filtered out), apart from that identical behavior like rAtE-P.dEt.
7.3 Water depth / level measurement
Water-proof sensors have to be used for water depth / level measurement.
Select the unit [m] for meters water column (selection mH2O) in menu
“Unit“.10 m water column (=water
depth) corresponds roughly 1 bar overpressure.
Measurings can be made e.g. like described below:
(for abs. pressure sensors SL has to be deactivated)
With an abs. pressure sensor:
Press „Tara‟ when sensor is at ambient air and then bring sensor to the
depth to be measured. The display shows now the depth in [m].
With a rel. pressure sensor: bring tube connection for lower press. in contact to ambient air by means of
a tube (no water contact!) and bring the sensor with its open pressure connection for higher pressure to
water depth to be measured (display and is compensated for pressure changes in ambient air).
