SMC Networks ISA3-F series, Operation Manual

Page: 95 / 116

4 How to use
-94-
No.PS
※※
-OMW0009-A
○Conversion formula of the process data and display value
(1) Conversion formula from the process data to the display value: Disp = a x PD + b
(2) Conversion formula from the display value to the process data: PD = (Disp
– b) / a
Disp: Product display value and set value
PD: Process data measurement value
a: Inclination
b: Intercept
[Inclination and intercept according to the product type]
Type Inclination a Intercept b
ISA3-F 0.02 0
ISA3-G 0.1 0
ISA3-H 0.2 0
[Inclination and intercept to the unit specification]
Unit Inclination a Intercept b
kPa 0.1 0
bar 0.001 0
psi 0.014504 0
[Calculation example]
(1) Conversion formula from the process data to the display value (process value)
(Units specification: kPa, PD = 1000)
Disp = a x PD + b
= 0.1 x 1000 + 0
= 100.0[kPa]
(2) Conversion formula from the display value (pressure value) to the process data
(Units specification: kPa, Disp = 120.0[kPa])
PD = (Disp
– b) / a
= (120.0
– 0) / 0.1
= 1200