| Calibration
Like sound level
meters, dosemeters are
calibrated
acoustically using an
external reference
sound source placed
over the microphone.
These reference
sound sources work on
the premise that so
many seconds’
exposure to the
reference signal will
produce a given dose
response from the
meter.
This response
will depend on the
reference signal used
and the form of the
output of the
particular dosemeter
(this may be as a
percentage dose or
directly as an L eq
value).
Further details
should be given in the
instruction manuals of
individual
instruments.
The more
sophisticated meters,
which act as logging
SLMs, are calibrated
in the same way as
ordinary SLMs, by
direct measurement of
a standard signal.
The calibration
should be checked at
the start and end of
measurement periods.
Dosemeters are
expected to run
unattended for periods
of up to 8 hours (a
full shift) so it is
important to ensure
that the batteries
will not fail during
this time.
To help in this
respect, most
instruments have a low
battery warning light,
which should come on
if the batteries have
less than 8 hours’
operating life
remaining.
An indicator
which comes on only 1
or 2 hours before the
batteries fail is of
limited use!
Manufacturers
can usually tell
roughly for how long a
dosemeter will run on
one set of batteries.
It is also good
practice to log the
number of hours each
dosemeter has been
used.
This will give
a rough idea of when
the batteries will
need changing.
» Basic
Construction
» Principles
of Operation
» Dynamic
Range
» Calibration
» Use
of Dosemeter in the
Field
»To add this site to your favourites
click here
|
