Operation
EGM-4 Operator's Manual – Version 4.19
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11
CFX-1 Open System Soil Respiration Chamber or CPY-3 Canopy
Chamber.
12
CPY-4 Canopy Assimilation Chamber (Closed System Operation)
Probe Setting Override
Some users may want to use the EGM-4 as a stand alone IRGA even with a sensor
connected. This option is available under 1EGM:
Press 1EGM. The Probe type should be set to the probe type connected to the EGM-4.
1. Press key N once until * appears next to :MV.
2. There should be a blank (no value) next to PROBE.
3. Press key Y to save.
4. Press key N to return to Main Menu.
If you now press key 1REC from the Main Menu, you will enter into the measurement mode
and the EGM-4 will act as a stand alone IRGA (See
Stand Alone CO2 Analyzer (Probe Type
on page 20.
2Z
Press 2ZERO to change the zero type and the time interval for performing zeros.
Changing the Zero Type
Press key 2 (2ZERO) and then key 1 to change the zero type used by the EGM-4. At
present, there are 3 types of zeros that can be performed:
Auto
This is the recommended ZERO type. The EGM-4 performs a Zero on start up,
then again after 2 minutes, then again after 4 more minutes, then after 8 minutes
and finally after 16 minutes up to a maximum interval set by the ZEROTIME.
ZEROTIME by default at start up is 20 minutes but it can be set from 1 to 40
minutes. This is the default mode on startup.
Manual
If selected, the EGM-4 performs a Zero on start up, then again after 2 minutes,
then again after 4 more minutes, then after 8 minutes and finally after 16 minutes.
After that, the user is responsible for performing ZEROS by pressing the 0 key
while in Measurement Mode.
Note, if the user fails to perform a ZERO after
40 minutes, one will be performed automatically.
EXT
A ZERO can be initiated by pulling DATA/ZERO REQ (Pin 10) line LOW.
(Connect to Ground Pin 8) Hold for 3 seconds and then break ground connection.
If no ZERO occurs after 40 minutes, one will be performed automatically.
An asterisk (*) indicates which ZERO type is selected. By default, the ZERO TYPE is set to
AUTO which is what we recommend.
To change the ZERO TYPE, press key 1 for AUTO, key 2 for MANUAL or key 3 for EXT.
Immediately after pressing the key, the asterisk (*) will be displayed next to your selection.
This will be the ZERO TYPE that will be used by the EGM-4 until changed again. Press key
Y to return to the 2SET menu.
ZEROTYPE *:AUTO
2:MANUAL 3:EXT
