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of the stain on the filter pad is then measured in a reflectometer and from this
reading is calculated the concentration of smoke in the air.
Sulphur dioxide, which is derived from the sulphur present in coal and in fuel
oils, is an important gaseous pollutant and its measurement is recorded as, combined
with smoke particles, it can seriously injure buildings and fabrics. There is, as
yet, no known economical method available of removing sulphur from fuel or from
flue gases.
This Council operates three smoke measuring stations at sites approved by the
Department of Scientific and Industrial Research, i.e., at Golders Green, Mill Hill
and Edgware Branch Libraries.
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