Sensor Head Warm-Up; Sensor Head Failure Modes - Aeroqual 200 series User Manual

3.3 Sensor Head Warm-Up

When the monitor is switched on the sensor needs to warm up to burn off any contaminants, there are
two stages:

3 minutes; sensor WARMING UP, no measurement

7 minutes; sensor stabilising, measurement is flashing
When not being used, keeping the monitor in 'standby' mode will keep the sensor heated and prevent
a build-up of contaminants.
If the sensor is new (or unused for long periods) it can take up to 24 hours for the message
WARMING UP (or SENSOR FAILURE in older models) to disappear. Should the message remain
after this time, a genuine sensor failure may have occurred, see Section 10.
For an ozone sensor, 24 hours is a conservative time to burn off contaminants and achieve its stated
performance specification. In most instances this will be achieved well within 24 hours. The warm-up
period can be reduced by subjecting the sensor to elevated ozone levels for a short period. For
example, 0.1 ppm of ozone for 5 minutes typically reduces the warm-up time to < 30 minutes.

3.4 Sensor Head Failure Modes

There are two possible sensor failure modes that will be indicated on the display:

SENSOR FAILURE, REPLACE SENSOR
The sensor head should be replaced as there has been a component failure.

SENSOR AGING (Ozone Low/Ultra Low sensor heads only)
The sensor has reached the end of its usable life, the measurement readings can no longer
be relied upon to be within specification.
See also Trouble shooting in Section 10.
MRK-D-0022 V4 Aeroqual Series 200, 300 & 500 User Guide
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