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9-2. Sensor Unit Installation/Replacement
1. Set the m
ain unit’s power switch to the OFF position.
2. Pull the latches on both sides of the base unit forward and lift the main unit to remove it from the base unit.
WARNING
Check that the target gas type and full scale value are correct before using a sensor unit. Also,
check that the sensor expiration date has not been reached.
Note: The expiration year/month is not indicated on a combustible gas sensor (CHS-7).
(2) Lift up the main unit
(1) Pull forward the latches on both sides
CAUTION
Sensor unit replacement should be performed every 6 months, except for combustible gas
sensors (CHS-7). Replace the expired sensor unit with a new one.
The expiration year/month is written on each sensor unit’s individual package. Replace the old one
with a new one before the expiration date.
Turn off the gas detector before sensor unit replacement.
Setting the main unit’s power switch to
the OFF position will generate a trouble alarm output (open collector is opened (OFF)). If the
trouble alarm output is used to operate the interlocks, etc. of the external devices, release the
interlocks, etc. beforehand, as needed, to prevent a possible activation of the interlocks during
replacement.
Main unit
’s power switch
To OFF position
Lift the cover flap open
