Description and operation
SF
6
gas monitoring
M20--002EN03
6/10
02--2011
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relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and commercial circumstances. It is
provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express written authority, is
strictly prohibited.
GRID
Measuring density
Pressure units
D
The international unit pressure is the Pascal (Pa), and hectopascal (hPa)
used for atmospheric pressure measurements.
D
The practical unit is the bar (14.503 p.s.i.)
1 bar = 1 000 hPa = 14.5 psi
1 bar = 100 kPa
10 bar = 1 MPa
D
Standard atmospheric pressure is equal to 1,013 hPa at sea level and an
air temperature of 20
°
C (68
°
F).
Measuring density
When it is not possible to directly measure density, this maybe checked using
an industrial pressure gauge capable of measuring the
effective pressure
.
An effective pressure value corresponds to the rated density, determined for
normal atmospheric pressure (1,013 hPa) and an ambient temperature of
20
°
C (68
°
F).
For each pressure reading (filling, inspection of densimeter thresholds...), the
rated effective pressure should be corrected according to the ambient tem-
perature and atmospheric pressure of the site at the time thereading is taken.
The real pressure is therefore :
P
real
=
P
rated effective in accordance with temperature
+
Δ
Pp
*
*
Δ
Pp
:
correction in accordance with atmospheric pressure
.
Summary of Contents for FKG1X
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