Yokogawa 212 Heat Calculator - Manual (Page 61)

6.6 4-20mA OUTPUT OPTION
A 4-20mA Output Option is available and can be used to retransmit the
volumetric flowrate, energy flowrate, temperature difference, feed temperature
and return temperature.
The maximum output voltage is the supply voltage less 6 volts. Therefore the
maximum load resistance can be calculated as:
Maximum Load =
Supply - 6
0.02
At 24 volts, Rmax = 900 ohms and at 12 volts, Rmax = 300 ohms.
Input & Output Connections 59