Perma Pure Baldwin-Series M225 - Manual (Page 14)

Section H: Test & Adjustment Procedures 14
For Current Output
(3a) If the auxiliary analog output board is set up for current output, set the ammeter
to 200ma range. Connect the ammeter to TB1 (the channel 1 current output
terminal), the black lead to the negative (-) terminal and the red lead to the positive
(+) terminal.
(4a) Adjust POT4 (the zero pot) to obtain a 4mA reading on the ammeter.
(5a) Set the thermocouple generator to 25
° C.
(6a) Adjust POT1 (the span pot) to obtain a 20mA reading on the ammeter.