Specifications

Ammonia Gas Monitor – Multi Zone
Instruction 3015-5113 39
Navigating to the Calibration Screen
On the System Setup screen, select the Calibration option (CAL).
Calibration Screen
Adjusting Calibration Factor
The factory default cal factor for standard units is 1.000. This value may be different if the high accuracy
option is ordered.
Proceed as follows to adjust the current calibration factor:
1. Use the PREV GAS or NEXT GAS options to select the appropriate gas.
2. Select the CAL FACTOR option to edit the value.
3. Use the LEFT/RIGHT cursor keys to move across the entry field and the UP/DOWN cursor keys to
modify the individual numbers.
4. Press ENTER to accept the new entry or ESC to revert to the previous setting.
Calibration Procedure
IMPORTANT: When calibrating the AGM-MZ a desiccant MUST be used to ensure all moisture is
removed from the purge air.
The CAL FACTOR is determined by sampling a known dilution of the type of ammonia gas to be sampled.
The sample must be prepared to less than half the desired accuracy and the concentration must be corrected
for ambient temperature and pressure at the time of measurement.
Calibration is best performed at or near full scale (1,000 PPM). It can, however, be done at any concentration,
and ideally in the range where maximum accuracy is desired down to, but not below, 100 PPM.
A cylinder of ammonia gas at a certified PPM level must be used to assure sampling occurs at ambient
conditions. A minimum sample size of 5 liters is required.
The AGM should be operating for at least one hour prior to performing a calibration.
Prepare the AGM-MZ for sampling by initially setting its CAL FACTOR to 1.000. Next, set up the AGM-MZ for
a logging interval of zero minutes, and place the AGM-MZ in its zone hold mode for the zone you wish to use
for calibration purposes.
Connect the sample bag directly to the intake port for the zone you have set up and allow the AGM-MZ to
sample the entire bag. When sampling is complete, view the trend data for the zone used to sample. Read
the measured PPM by placing the cursor on the spikes cause by the sample. If the bag was large enough for
multiple samples, average the most stable ones.
The new CAL factor is computed by dividing the known gas value by the measured value. Typically this value
will be between 0.95 and 1.05. This value is stored in non-volatile memory.