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44
Volumetric Recording Apparatus
Hie apparatus enables both smoke and sulphur dioxide to be estimated. Air is drawn
by means of a pump, first through a filter paper then through a drechsel bottle and
finally a meter. The filter paper removes the smoke, leaving a discoloured patch
on the paper. The drechsel bottle contains a weak solution of hydrogen peroxide
which reacts with the sulphur dioxide to form a sulphuric acid and the meter measures
the volume of air passing through the apparatus in a known time. The density of the
smoke stain is proportional to the amount of smoke in the air and can be measured
by means of a photo-electric reflection densitometer The sulphur dioxide is
estimated by a simple chemical titration. From tables provided by the Warren
Spring Laboratory of the Department of Scientific and Industrial Research at
Stevenage, the amount of smoke or sulphur dioxide in a known volume of air can then
be calculated.
Automatic Sequential Smoke Recorder
In November an additional piece of smoke recording apparatus was loaned to the
Department by the Warren Springs Laboratory for a special investigation which it was
hoped to carry out in London early in 1962
This apparatus measures the smoke in the atmosphere by filtration through a filter
paper but, in this case, the filter paper is in a continuous roll and is changed
automatically every hour three hours or 24 hours as may be selected beforehand.
This apparatus enables variations in smoke concentration during a day to be recorded.
The apparatus described above merely gives the total smoke recorded during a period
of 24 hours Quite marked variations are found to occur in Winter from hour to
hour and it is hoped to investigate the relationships between these short-term
variations and chest complaints such as bronchitis, in the hope of finding some
connection
This apparatus has been installed at the Town Hall alongside the normal equipment
mentioned above
EXHAUST FUMES FROM DIESEL VEHICLES
The practice outlined in my report for I960- in which emissions of heavy
exhaust smoke from vehicles were brought to the notice of the vehicle owners, has
continued
During 1961 six diesel operated vehicles were observed in the Borough to be emitting
dark smoke of a sufficient density to warrant the attention of the owners being drawn
to the fact It is, of course, in a firm's own interest to have a vehicle examined,
as it is general experience that where black smoke is produced from a diesel engine,
either the engine needs overhaul or adjustment or it is not being operated correctly and
the emission of black smoke represents wasted fuel. Without exception, all six firms
proved most co operative in having the vehicles immediately withdrawn from service,
examined and the defect remedied.
CLEAN AIR ACT, 1956
Section 3: Notices of Intention to Install Furnaces
The following notices were received during the year:-