Calculation of the constant
k
The constant k can be calculated because of a work point reference, with which the mass flow (MF_REF), the differential pressure (IN_REF), the absolute pressure (P_REF) and the absolute temperature (T_REF) are recognized.
When the input IN is a Differential pressure the equation says as follows:
When the input IN is not a Differential pressure the equation says as follows:
Specification of the calculation
With the calculation, a simple multiplication is entered:

. In order to achieve pressure or temperature compensation, the parameters
en_pres or
en_temp must be set to 1. The square route is also only active when
en_sqrt = 1.
When one of the parameters en_sqrt, en_pres, en_temp remains at 0, the calculation of the constant k must be adjusted to correspond (delete the square route, replace from P_REF or T_REF through 1)
The temperature TEMP can be printed out in degrees Celsius or degrees Fahrenheit, depending on the value of the parameter tc_tf :
tc_tf
|
Temperature unit from TEMP
|
0
|
Degrees Celsius
Calculation of the absolute temperature TA:
|
1
|
Degrees Fahrenheit
Calculation of the absolute temperature TA:
|
The pressure PRES can be printed out in any unit, as absolute or relative pressure, according to the value of the parameter pr_pa.
pr_pa
|
Pressure unit from PRES
|
0
|
Relative pressure
Parameter pu must conform to the unit 1 atmosphere.
Calculation of absolute pressure: PA = PRES + pu
|
1
|
Absolute pressure: PA = PRES
|