18 • Chapter 3: Measuring Mode
04 Series for CO(-H2)
10. If
A.ZERO
is set to
ON
(factory setting is
OFF
, see pg.83), the instrument prompts you to
do an auto zero. An auto zero operation sets the reading to 0 ppm.
WARNING:
Make sure that the instrument is in a known fresh air environment (an
environment free of combustible or toxic gases and of normal oxygen
content, 20.9%) before performing an auto zero operation. If you perform
an auto zero operation in an area with gases present, the adjustment will
not be accurate.
You must press and release the POWER MODE button to perform an auto zero function.
If you do not press any key, after 15 seconds, the instrument enters Measuring Mode
without performing an auto zero.
If
Password Protection
is turned
On
(factory setting is
Off
) using the 04 Series Setup
Program, a user-set password is required to perform an auto zero. When the password
screen appears, adjust each digit with the AIR button and press and release the POWER
MODE button to move on to the next digit. Once the password is entered, the instrument
performs the auto zero.
11. The CO-04C is now monitoring for gas in Measuring Mode. The Measuring Mode Screen
displays the current gas reading.
Performing a Demand Zero
Perform a demand zero before using the CO-04C. This sets the reading to 0 ppm.
1. Find a fresh-air environment. This is an environment free of toxic or combustible gases
and of normal oxygen content (20.9%).
2. Turn on the unit as described above in “Turning On the CO-04C”.
3. Press and hold AIR. The buzzer pulses and the LCD prompts you to continue holding AIR
(if
KEY.TONE
is set to
ON
in User Mode).
4. Continue to hold AIR until the LCD prompts you to release it. The CO-04C sets the fresh
air reading. Start up is complete and the unit is now ready for monitoring.
A .ZERO
YES .MODE
NO .AIR
0000
PASS-W
CO
0
ppm