Endress+Hauser Fieldbus Micropilot M FMR244 Operating Instructions Manual page 91

Micropilot M FMR244 with FOUNDATION Fieldbus
Reaction time
Effect of gas phase
Gas phase Temperature
°C °F
Air 20 68
Nitrogen
200 392
400 752
Hydrogen 20 68
200 392
400 752
Gas phase Temperature
°C °F
Water 100 212
(saturated
180 356
steam)
263 505.4
310 590
364 687.2
Endress+Hauser
The reaction time depends on the parameter settings (min. 1 s). In case of fast level changes, the
instrument needs the reaction time to indicate the new value.
High pressures reduce the propagation velocity of the measuring signals in the gas/vapor above the
fluid. This effect depends on the gas/vapor and is particularly large for low temperatures. This
results in a measuring error that gets bigger as the distance increases between the device zero point
(flange) and product surface. The following table illustrates this measured error for a few typical
gases/vapors (with regard to the distance; a positive value means that too large a distance is being
measured):
1 bar/14.5 psi 10 bar/145 psi
0.00 % 0.22 %
-0.01 % 0.13 %
-0.02 % 0.08 %
-0.01 % 0.10 %
-0.02 % 0.05 %
-0.02 % 0.03 %
1 bar/14.5 psi 10 bar/145 psi
0.20 % —
— 2.1 %
— —
— —
— —
Note!
When the pressure is known and constant, this measured error can, for example, be compensated
by means of linearization.
Pressure
50 bar/725 psi 100 bar/1450 psi
1.2 % 2.4 %
0.74 % 1.5 %
0.52 % 1.1 %
0.61 % 1.2 %
0.37 % 0.76 %
0.25 % 0.53 %
Pressure
50 bar/725 psi 100 bar/1450 psi
— —
— —
8.6 % —
— 22 %
— —
Technical data
160 bar/2320 psi
3.89 %
2.42 %
1.70 %
2.00 %
1.23 %
0.86 %
160 bar/2320 psi
—
—
—
—
41.8 %
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