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3-3. Normal Operation Functions
This section describes functions which are available during normal operation thru button
operation. “Normal operation” is a status in which the detector is capable of gas
monitoring/detection after powering-up, and normally the <gas concentrations> screen is
displayed on the LCD.
3-3-1. Air Adjustment (Zeroing) (21.0 vol% adjustment for Oxygen)
During normal operation, press and hold the [ AIR ADJ.] button for 3 seconds to start air
adjustment.
--> The unit will beep 3 times and [ADJ] will be displayed for each target gas for 3
seconds. When the air adjustment is completed, [21.0vol%], [0%LEL] or [0ppm] will
be displayed for each corresponding gas.
3-3-2. Peak Hold
1) During normal operation, press the [ POWER] and [ AIR ADJ.] buttons
simultaneously to activate the peak hold function.
--> The unit will beep once, the PEAK icon will appear at the
bottom of the LCD. If a highest concentration (lowest for
oxygen) is detected, it will replace the current peak value. The
new peak value will be maintained on the LCD until exceeded.
2) To deactivate the peak hold function, press the [ POWER] and [ AIR ADJ.]
buttons simultaneously.
--> The unit will beep once, the PEAK icon will disappear, the peak value will be
reset, the LCD will then return to the <gas concentrations> screen.
Air adjustment completed
Perform air adjustment (zeroing) in clean air. Inaccurate gas
concentrations will be indicated if air adjustment has been done
in a gas atmosphere.
During normal operation, the unit keeps monitoring the gas
concentrations even when the <gas conce
ntrations> screen is not
displayed on the LCD and an alarm will activate when any of the gas
concentrations reach the alarm set value.
NOTE
MENU
MENU
The peak hold function will be canceled each time the unit is turned off.
Once the peak hold function is activated, the new peak value will be updated
and maintained on the LCD even if the actual gas concentration falls below
that value.
NOTE
WARNING
▲
▲
▲
Air adjustment
in progress
Peak hold
When proper air adjustment is not available (e.g. when the actual
concentration exceeds the alarm set value), [ADJ] will not be
displayed and the concentration value will remain displayed for this
gas, even after the [ AIR ADJ.] button is pressed for 3 seconds.
NOTE
▲
O
2
drifts to 21.2%
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TWA Alarm
For hydrogen sulfide (H
2
S) and carbon monoxide (CO), the gas concentration average
is calculated every minute. These averages are integrated and updated every minute
while the detector is on. If the integrated value exceeds the integrated alarm set value
(see below for how to obtain the integrated alarm set values), a TWA alarm will activate
and the flashing alert will be shown in the bottom right corner of the LCD.
[Integrated alarm set values]
Hydrogen Sulfide: 10 ppm x 8 hours x 60 times (60 times/hour) = 4,800 ppm
Carbon Monoxide: 25 ppm x 8 hours x 60 times (60 times/hour) = 12,000 ppm
STEL Alarm
For hydrogen sulfide (H
2
S) and carbon monoxide (CO), the gas concentration average
is calculated every minute. If the average during the last 15 minutes (15 samplings)
exceeds the STEL alarm set value (15 ppm for H
2
S and 300 ppm for CO), a STEL alarm
will activate and the flashing alert will be shown in the bottom right corner of the LCD.
DANGER
TWA alarm will not be cancelled until the detector is turned off.
NOTE
STEL alarm will not be cancelled unless the average during the last 15
minutes falls below the STEL alarm set value or the detector is turned off.
NOTE
When a gas alarm activates, immediately take all the necessary
measures to prevent an explosion.
Flashing
Flashing
(H
2
S)
Flashing
(CO and H
2
S)(CO)
Flashing
(CO)
(H
2
S)
Flashing
(CO and H
2
S)
Flashing
