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二、OPERATION MANUAL
2.1 INSTRUMENTS OPERATION
1. To turn on the instrument AS8900, please depress and
hold the button for over 1 second, the unit will be
turn on with a beep sound and vibration, then the lcd
will light up all icon and segments. Once the software
countdown for 18 seconds then the unit will enter into
the Gas Monitoring mode.
2. for to turn off the unit, please depress and hold the
button for over 3 seconds, then the unit will be power
off after 3 beep sounds.
3. for to light up or turn off the backlight of the LCD
display, please depress the button.
2.2 Gas Monitoring mode
1. once the unit is power on, the
display will show all 4 gas symbol
with readings.
2. then the unit is already started to
continuously monitored and shows
the readings on the LCD display.
Once the gas level is increase, the
corresponding read will be showed
the existing gas concentration.
3. Also the battery life indicator is also display in the left
upper corner, onr the battery lift is decreased, the shaded
showed of the battery icon is alco decreased.
4. Once the gas concentration is exceed the high or low
alarm limit (as well as TWA or STEL) the unit will be
triggered the audio and visual alarm with vibration.
Operation
Explanations
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5. Once the gas concentration is drop below the alarm level,
the unit will go back to normal gas monitoring mode.
6. For to access this mode, please depress button. Then
the unit will enter to Zero/Calibration mode.
2.3 Zero/ calibration mode
1. Depress the button once from the
gas monitoring mode, the unit will be
put in the Zero/ Calibration mode.
2. In this mode the icon and will
be displayed along with the 4 gases
readings.
3. Depress the button once more
time,the unit will escape to another
Peak Value mode.
4. If depress button the unit will start
the Zero/ Calibration process. Once
the CO, H2S and LEL sensors have
finished the zeroing process, the
Oxygen sensor will be start to SPAN.
5. During this process the “CLOCK”
icon and full Oxygen span value will
be displayed.
6. Once the process is completed, the display will shows the
SPAN and icon
7. To depress the button, the unit will begin to calibrate
the remaining sensors one by one with same process.
8. the calibration gas are the fixed concentration value, to
calibrate the instrument by using a blended cylinder
containing 25ppm H2S, 100ppm CO, 25% or 50% LEL
Methane or pentane, and 19% Oxygen at 0.5 LPM flow
speed.