An electronic transmitter with an output of 4 – 20 mA is calibrated for a pressure range of 7 – 10 MPa(g).
What pressure is represented by a 12 mA signal?
Solution
Signal Span or Span of transmitter 20 mA – 4 mA = 16 mA
Output Signal = 12 mA
Live Zero = 4 mA
Base Point = LRV of Range = 7
Process Span = URV -LRV = 10 – 7 = 3
Fraction of Measurement Change = 12 – 4 / 16 = 0.5
Actual Process Change = (Fractional Change) x (Process Span)
Actual Process Change = 0.5 x (10 – 7 MPa) = 1.5 MPa
Actual Process Value = Base Point + Process Change
Actual Process Value = 7 + 1.5 MPa = 8.5 MPa(g)
Result :
Pressure at 12 mA is 8.5 MPag
Also Read: Instrumentation Formulas & solutions
Similar Articles:
- Formula for Process Variable to Percentage Conversion
- Formulas to calculate ma from PV, LRV and URV
- Formula for Percentage to Process Variable Conversion
- 4-20mA Graphical Calculations
- Calculate Flow Transmitter Output Current
- PLC Analog Input Card Resolution Effects on Accuracy
- Calculate Temperature Transmitter Output
- Transmitter Turndown Ratio, Set Span and Zero Span
- Hydrostatic Level Transmitter Questions
- Calculate Process Variable from Transmitter Current
1 comment
This is one of the very beautiful website i have ever come across. Thank you so much Sir. S. B. Reddy for your great efforts and dedication. Thanks for this gift of knowledge.