Super Systems H2 Sensor - Manual (Page 13)

Hydrogen (H
2
) Sensor Operations Manual
Super Systems Inc. Page 13 of 17
Calibrating the Sensor using Modbus Registers
Performing a Zero Calibration
1. Begin the flow of Zero gas (Nitrogen or Argon) at a rate of 1.5 SCFH.
2. Allow the readings from the sensor to stabilize.
3. Set Register #13 to 0 (equal to 0% H
2
).
4. Set Register 12 to 1.
Performing a Span Calibration
1. Begin the flow of Span gas (with a known %H
2
) at a rate of 1.5 SCFH.
2. Allow the readings from the sensor to stabilize.
3. Set Register #13 to the H
2
value in the span gas. Multiply the gas value by 100 before
entering the number (i.e. if the gas has 40.13%H
2
, enter a 4013 or if the gas has 9.97% H
2
enter a 997 into Register 13).
4. Set Register 12 to 2.
Changing the 4-20mA Assignments using Modbus Registers
Register 19 denotes the assignment for 4-20mA #1, and register 23 denotes the assignment of
4-20mA #2. The default value for #1 is %H
2
, and #2 is #DA. To change the assignment, enter a
number into either register according to the following list:
• 0 = %H
2
• 1 = %DA
• 2 = %NH
3
• 3 = %Kn
• 4 = External Source