Casella CEL CEL-181 - Manual (Page 6)

Casella USA
17 Old Nashua Road #15
Amherst, NH 03031-2839
www.casellausa.com Page 6 of 14 tel: ( 800) 366-2966
[email protected] 27 Jan 2006 fax: (603) 672-8053
3 Operating the Instruments
3.1
Dose Meter Calibrator Type CEL- 182
The Dose Meter Calibrator has been developed
to enable the rapid and convenient checking of
the CEL range of Noise Dose Meters. The
description CEL-182 Dose Meter Calibrator
complete refers to the following items:
CEL-182
Dose Meter Calibrator
6LF22 Battery (PP3) 9V
In order to prevent the calibrator from becoming
activated during transit the battery, although
fitted, has not been connected. To connect the
battery in the calibration unit it is necessary to
carefully unscrew the barrel. The battery
compartment is located beside the printed circuit
panel. When inserting or removing the battery it
is important that this panel is not disturbed. On
no account should the preset controls within the
instrument be adjusted. In connecting the
battery it is essential to ensure that the correct
polarity is maintained for if the battery is
inadvertently connected, even momentarily,
having reversed polarity, the circuit elements will
be damaged. Having connected the battery it
may be carefully slid into its retaining clip.
To operate the unit, simply depress the Dose
switch located on the top face of the calibrator.
The unit will then run for the set period to deliver
the standard noise dose. The light emitting
diode indicator will light as soon as the ON
switch is depressed and the calibration cycle will
commence when the switch is released. The
light will remain on throughout the calibration
cycle. Should the indicator extinguish itself as
soon as the switch is released this indicates that
the battery has become discharged and must be
replaced. Care should be taken not to
accidentally activate the ON switch once the
calibration cycle has commenced as this will
restart the timer resulting in an incorrect noise
dose being generated.
The calibrator will deliver a level of 11 6.5dB for
65.5 seconds, which corresponds to a dose of
100%, on units with a 90dB criterion level and
an exchange rate of 3dB whilst it will of course
produce a different result on instruments having
alternative calibration settings. Full details are
given in the table shown in Fig 2.
It must be remembered that the sound pressure
level generated by the calibrator is inversely
proportional to the enclosed volume of the
calibration cavity. The precision measurement
microphone fitted to the CEL-180 versions of the
instrument has a larger volume that the
microphones fitted to the CEL-181 types. This
results in a calibration level of 115.5dB when
this calibrator is used on CEL-180 instruments
resulting in a lower exposure count; here again,
reference should be made to Fig 2.
3.2 Noise Dose Meter
3.2.1 Schedule of Parts
The description Noise Dose Meter complete
refers to the items listed in the following
schedule and upon receipt should be checked
against this list:
CEL-180/181 Personal Noise Dose Meter
*CEL-186 Precision
Measurement
Microphone
CEL-2835 Microphone Calibration Coupler
(CEL-2834 provided with
CEL-181 types)
*CEL-D2289 Microphone Dress Clip
SP 1074
Survey Pad
8BA Allen Key
RS 1 Screwdriver
6LF22 Battery (PP3)
Bar Magnet
D-1951 Slide Rule provided with
'C, E, F & G' versions,
whilst type D2230 is
provided with H & J
versions, None provided
with other types.
**D 3430 Presentation Case
As an accessory, the
CEL-3482 windscreen
and dustcover is available
for use with these
instruments and they should
be ordered separately.
*0nly provided with the CEL 180 types
**As an alternative, the D3429 case is available
that accepts five dose meters and one
calibrator.