Operation
EGM-4 Operator's Manual – Version 4.19
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2. The pressure regulator should be set to a very low pressure and there should be a slight
flow excess gas venting from the open “T” Piece (approx. 250 ml/min). We recommend
using a flow rate from the gas cylinder of approximately 200-400 ml/min.
3. Press key N and enter the CO
2
concentration of the calibration gas that you are using.
This value must match the certified CO
2
concentration of the calibration cylinder and be
similar or higher than the anticipated measurement range of the instrument (
i.e.
it is best
to calibrate the instrument with a reference gas containing 350 - 450 ppm CO
2
when
measuring around 350 ppm CO
2
).
4. The EGM-4 will then perform a ZERO. At completion of successful ZERO, a similar
message to the following will be displayed.
5. At this point, all you are looking for is that the CO
2
concentration is steady.
Note, the
displayed value may not be the value you entered in step 1 above.
When this value
is steady (i.e. not changing by more than 1 ppm after 30 seconds), press the 0 key.
Control is passed to the VOUT Set Menu to provide the opportunity to change the scale
factor if desired. If no change is desired, press key Y.
6. Calibration is complete. The new calibration and linearization constants are stored in
non-volatile memory.
4DMP
Press key 4 to view/transmit stored data.
Stored data can be viewed on the instrument LCD display or transmitted to your PC computer
using our data transfer software. The EGM-4 will store up to 1,000 records in memory.
Note,
when the memory is full, the oldest record will be overwritten each time additional
records are taken. Also note that the record number restarts at 1 when the EGM-4 is
powered off. Therefore, more than one record number 1 with different time stamp can
exist in memory.
Screen Display
To view stored data on the LCD display, press key 1. The latest stored record is displayed
first. Each record has 3 different displays associated with it as follows:
Display 1
Where:
REC
Record Number
PLOT
Plot Number
04-01
Date (4
th
day of January)
11:52
Time
1:SCREEN DISPLAY
2:DATA DUMP 1-2?
CO2 CONC = 1050
KEY0 WHEN STEADY
REC 0000 PLOT 01
04-01 11:52
