Setra System Model SRMD - Manual (Page 5)

4.2 Zero and Span Calibration
Set the Voltage Source to 0 VDC and Connect the Voltage Source to the +S
and COM terminals on the display.
Check the field sensor input and output specification.
Example:
humidity Sensor 0-100% Rh and 0 to 5 VDC output
Temperature Sensor 50-90°F and 0 to 10 VDC output
Setup humidity Sensor:
Apply 0 V and if necessary turn the ZERO potentiometer (pot) until the display
reads 0.0, apply 5 VDC and turn the pot labeled 5V until the display reads
100.0
Setup Temperature Sensor:
Move the range jumper from the 5V to 10V position. Apply 0 VDC and turn
ZERO pot until the display reads 50.0, apply 10V and turn 10V pot until display
reads 90.0
4.3 Adjust Display Brightness
While looking at the display, turn the Display brightness adjust pot, (See Fig. 4)
to the desired brightness.