-31-
(2) Sampling gas flow rate (flow-rate icon check)
Check that the flow-rate icon (at the top-right corner of the LCD) is quickly spinning. Refer to 7-1.9
―Check
the flow rate of the sampled gas
.‖
If the flow-rate icon slowly spins or stops, check the filter element for contaminants. If the filter element
(FE-1) is dirty, replace it with a new one. Refer to 9-1.
―Filter Element Replacement‖ for the procedure. If
the flow-rate icon does not return to normal operation (quickly spinning), check the tubing for clogging or
excessive negative pressure.
(3) Airtightness
Check the airtightness of the unit by referring to 7-1.10
(4) Filter element replacement
Check the filter element for contaminants at least once every 6 months and replace it if needed. The filter
element is likely to clog faster in a severe environment. If the clogging notification (flow-rate icon slowly
spins or stops) appears on the LCD, check the filter element. Replace it with a new one, if dirty. Refer to
9-
1. ―Filter Element Replacement‖ for the procedure.
(5) Check the tubing
Check that the tubing has been done correctly at startup or relocation. If the tubing is incorrect, gas
sampling from the target place is not possible, and an appropriate flow rate cannot be maintained.
(6) Sensor unit installation/replacement
Install a new sensor unit into the gas detector at startup, and replace it with a new one every 6 months,
except for combustible gas sensor units (CHS-7)
.
Refer to 9-
2. ―Sensor Unit Installation/Replacement‖ for
the procedure.
(7) Sampling unit replacement
Replace the sampling unit with a new one every 3 years. For the procedure, refer to 9-
3. ―Sampling Unit
Replacement
.‖
(8) Loop check and alarm test using the TEST switch
Press the TEST switch with the test stick to send a pre-set analog output to the host system. Check the
output at the host system. Press the TEST switch again to return the output to normal. For this, refer to 7-4.
―Test Mode‖.
CAUTION
To maintain the reliability of the gas detector, perform a gas alarm test by using the TEST
switch, etc. at least once a month.
While in the test mode (alarm test using the TEST switch), the gas alarm contacts activate. If
the gas alarm contacts are 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 the test mode, or
Enter the maintenance mode before entering the test mode. Release the interlocks of the
external devices beforehand, if needed (refer to 7-
5. ―Maintenance Mode‖).
Notify those concerned before starting a gas alarm test.
