3 Maintenance
3.1 Periodic Maintenance
It is essential that the test and calibration schedule be adhered to. Honeywell Analytics recommends the following maintenance schedule:
•Response test prior to each use. Expose sensor to a sample of the target gas to verify proper sensor response and alarm functions.
•Calibration should be performed with certified calibration gas every six months, and all tests must be logged.
•Check filter material every six months. Replace if dirty or moist.
•If the optional sensor keeper is used for extra
3.2Sensor Life
The electrochemical SMART CELL is extremely reliable, but the following can cause the cell chemicals to become depleted:
•A period of time
•Exposure to high temperatures
•Exposure to high concentrations of the target gas
•Exposure to high moisture
When the cell becomes depleted, the unit will give no indication of failure other than that the sensor will not respond. For this reason it is absolutely essential that these units be exercised with a gas sample on a regular basis.
Typical sensor life under normal use is two years or more.When the
3.3 Calibration
Calibration is recommended every six months in normal use. Each
The calibration procedure requires the use of a bypass tee to allow the gas to be drawn into the flow cell without creating variable pressure or dilution problems. Calibration gas cannot be fed into the flow cell under pressure.
When applying calibration gas use the bypass tee as shown in Figure 4 on page 11. The flowrate of calibration gas should be high enough that at least 0.5 SCFH is flowing out of the calibration tee. This can be measured with the supplied flowmeter and insures that air is not being drawn into the unit and diluting the calibration gas.
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