Ion Science MVI - Manual (Page 18)

MVI MANUAL Ion Science Ltd
Page 18 of 23
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Interferences
The MVI detector operates on the principle of UV light absorption. There are substances other than Mercury
which also cause light absorption and these substances are known as interference vapours.
Some of the interference vapours encountered are various hydrocarbons, water vapour, Sulphur compounds
and particles such as smoke. There is no measurable interference from Carbon Monoxide, Carbon Dioxide
or Ammonia. High concentrations of water vapour will give readings of between 5 to 10 µg/m³, however if
the MVI is zeroed at a similar humidity, this will not be seen under normal variations in the ambient
atmosphere.
Table of some interferences at 100 ppm concentration:
Compound
Reading in µg/m³
Benzene
20
Toluene 3.5
Acetone 3.0
Ethyl Alcohol 6.0
Ethyl Acetate 3.0