Ec-F9-Nh3 Calibration Procedure - Honeywell VA201T Calibration Handbook

EC-F9-NH3 Calibration Procedure

General Information
The Manning EC-F9 sensor should be calibrated a minimum of once every six months, or after exposure to a
large concentration of gas. The Manning EC-F9 generally becomes less sensitive with age, therefore regular
calibration is critical to maintain the accuracy of the sensor.
Refer to the Manning EC-F9 sensor manual for more in-depth calibration procedure details.
Zero Calibration
There is no zero pot as the pre-amp is factory zeroed and should not require any further adjustment.
Span Calibration
NOTE: If the sensor output is erratic immediately after the installation of a new cell, it may be a high gain
(span) setting left over from a previous cell that was adjusted for aging.
Confirm that the sensor is in clean air or there is no ammonia present. Output should not be more than
4.6 mA (46 mV from Test[—] to Test[+]).
The table below shows what span gas to use and what the signal should be for various sensor ranges:
Sensor Range
Place calibration adapter firmly over the sensor.
Apply span gas at 1.0 L/min (span gas must be in air, not nitrogen or other carrier).
After span gas has been on sensor for two minutes, adjust the span pot until the correct output is achieved.
For combinations not shown in the previous table, use the following formula to determine the output:
Where:
SGC = Span Gas Concentration,
SFSV = Sensor Full Scale Value.
For example, if 100 ppm SGC gas is used to calibrate a 250 ppm SFSV sensor, the signal would be as follows:
If the correct output cannot be achieved, a replacement cell is required.
Manning EC-F9-NH3
Span Gas
(ppm) (ppm)
0—100
0—250
0—250
0—500
0—1,000 1,000
Signal (mA) =
100 ppm
Signal =
250 ppm
10.4 mA = 104 mV from TEST (—) to TEST (+)
Calibration Handbook
Calibrated Signal Voltage
100
250
100
250
SGC
x 16 + 4
SFSV
x 16 + 4 = 10.4 mA
63
(mV)
200
200
104
120
200