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4-20 ma to temperature?

Hello,
We have furnace controller that uses a type C thermocouple to report temperature. I wanted to use a 4-20ma output from the controller and use it as an input for the datataker and have it convert to temperature. I know the datataker can convert mV to temperature, but what about mA? Is this possible?

Hello, We have furnace controller that uses a type C thermocouple to report temperature. I wanted to use a 4-20ma output from the controller and use it as an input for the datataker and have it convert to temperature. I know the datataker can convert mV to temperature, but what about mA? Is this possible?

Hi Rheniumjoe,

It is correct dataTaker can convert mV from thermocouple to temperature and the process happens internally (no need to add calculation for conversion).

When you have mA signal that need conversion to temperature, you can utilise scaling function. Usually the controller will provide an information about 4-20 mA representation over temperature range (in your case thermocouple reading). You can use that information for scaling.

For example:
Thermocouple type C has a range of 0- 2320 degC, but the controller use 4-20 mA to represent 0-1500 degC, then the scaling would be (remember 4-20 mA channel in DT will give a result of 0 - 100% in place of 4-20mA):

BEGIN"READ"
S1=0,1500,0,100
RA1M LOGONA
1*L(S1,"Temperature~degC") 
END

Best regards,
Rudy Gunawan

Hi Rheniumjoe, It is correct dataTaker can convert mV from thermocouple to temperature and the process happens internally (no need to add calculation for conversion). When you have mA signal that need conversion to temperature, you can utilise scaling function. Usually the controller will provide an information about 4-20 mA representation over temperature range (in your case thermocouple reading). You can use that information for scaling. For example: Thermocouple type C has a range of 0- 2320 degC, but the controller use 4-20 mA to represent 0-1500 degC, then the scaling would be (remember 4-20 mA channel in DT will give a result of 0 - 100% in place of 4-20mA): ```` BEGIN"READ" S1=0,1500,0,100 RA1M LOGONA 1*L(S1,"Temperature~degC") END ```` Best regards, Rudy Gunawan
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