Siemens SITRANS P500, Operating Instructions Manual, Page: 152 / 238

Operate
6.3 Description of the operating functions
SITRANS P500 with HART
152
Operating Instructions, 12/2014, A5E02344528-09
Figure 6-12 "Mass flow" measurement type
Example
The "Input scaling, pressure" function defines the pressure range of 0 to 2 bar that is
interpreted as 0 and 100% by the following square root extracting function. In the following
diagram, a process pressure of 0.5 bar is assumed.
In the "mass flow" measuring mode, a square root extraction characteristic "srlin2" with a
root application point of 10 % is applied as standard.
In the calculation example the input value for the "root extraction function" is about 25 % for
a prevailing process pressure of 0.5 bar. The output value is about 50 %.
MA Start of scale value p Pressure
ME Full scale value MF Mass flow
Figure 6-13 Calculation of the mass flow
In the calculation example, the two value pairs 0 %;0 % and 100 %;50 % are assigned as
parameters to the correction characteristic. This setting corresponds a halving of the input
value for all output values.