User's Manual

DRAFT
Micropilot FMR53, FMR54
Endress+Hauser V. 1, Rev. 7, 26-10-2012 31
Gas layer Temperature Pressure
°C °F 1 bar (14,5 psi) 10 bar (145 psi) 50 bar (725 psi) 100 bar (1450 psi) 160 bar (2320 psi)
Water
(saturated
steam)
100 212 0.02 % - - - -
180 356 - 2.1 % - - -
263 505,4 - - 8.6 % - -
310 590 - - - 22 % -
364 687 - - - - 41.8 %
When the pressure is known and constant, this measured error can, for example, be compensated by
means of a linearization.
Gas phase compensation with
external pressure sensor
(PROFIBUS PA, in
preparation)
PROFIBUS devices can receive the signal of an external pressure sensor through the bus and use it to
perform a pressure dependent time-of-flight correction. In the case of saturated steam in the temperature
range from 100 to 350 °C (212 to 662 °f), for example, the measuring error of the distance measurement
can be reduced by this method from up to 29 % (without compensation) to less than 3 % (with
compensation).