Appendix 4 – Sensor
Limitations
Standard Detective+ units detect flammable gases using a catalytic flamma-
ble sensor which operates in the presence of oxygen. It is advisable to check
the oxygen concentration as well as the flammable gas concentration before
entering a confined space. Depleted Oxygen levels will reduce a flammable gas
reading.
The performance of catalytic sensors may be permanently degraded if exposed
to silicones, sulphur containing gases (such as H2S), lead or chlorine com-
pounds (including chlorinated hydrocarbons).
The instrument is not suitable for use in ambient temperatures above 50°C and
electrochemical toxic gas sensors may be degraded at these temperatures.
Water should not be allowed to collect on the sensors as this may impede gas
diffusion. Use with care in wet or humid environments where water may con-
dense on the sensors, and check response after use.
Persistent exposure to high levels of toxic gas can shorten the life of toxic sen-
sors. Toxic sensors may also be cross-sensitive to gases other than their specific
target gas, and hence the presence of other gases may cause the sensor to
respond. If unsure, contact Crowcon or your local agent.
Use of high power radio transmitters in close proximity to the instrument may
exceed RFI immunity levels and cause erroneous indications. If such problems
are experienced, remove antennae to a reasonable distance from the instru-
ment (e.g. 30 cm).
To Next Page
Loading...
