Section 5 - Temperature Output Calculations
To calculate Temperature by measuring the current or voltage output, use the
following formulas.
a) To calculate temperature in ºC from a 4 to 20mA current output in °C for the
temperature range of -30 to 75ºC
Formula:
Temperature in °C = [(Output current measured in milliamp -4) ÷ (0.1524)] - 30
Where: 4 = Offset current in mA
30 = Offset temperature in °C
0.1524 is the sensitivity, which derived from the following:
(Full scale current limit)/(total temperature range)
16 mA/105ºC = 0.1524mA/ºC
b) To Calculate temperature in °F from a 4 to 20mA current output in ºF for the
temperature range of -22 to 167ºF
Formula:
Temperature in ºF = (Output current measured in milliamps – 4) ÷ (0.0847)] -22
Where 4 = Offset current in mA
22 = Offset temperature in °F
0.0847 is the sensitivity, which derived from the following:
(Full scale current limit)/(total temperature range)
16 mA/189ºF = 0.0847mA/ºF
c) To calculate temperature in °C from a 0 to 1 volt output for the temperature
range of -30 to 75ºC
Formula:
Temperature in ºC = (Output voltage measured ÷ 0.0095) - 30
Where: 30 = offset temperature in °C
0.0095 is sensitivity, which derived from the following:
(Total out put voltage range)/(out temperature range)
1.0 v/105ºC = 0.0095 V/ºC
d) To calculate temperature in °F for 0 to 1 volt output for the temperature
range of -22°F to 167°/F
Formula:
Temperature in ºF = (Output measured in volts ÷ 0 .0053) - 22
Where 22 + Offset temperature in °F
0.0053 is sensitivity, which derived from the following:
(Total out put voltage range)/(out temperature range)
1.0 v/189ºF = 0.0053 V/ºF
The same calculation method will apply to the 0 to 5 volt and 0 to 10 volts
models.
5-1
Temperature Output Calculations
5
