SV 104 USER'S MANUAL_
DRAFT
_______________________________________________
_
33
4.7
CALIBRATION
The SV 104 dosimeter is offered with the dedicated
SV 27
MEMS microphone with ½” housing.
It makes the calibration very easy by direct usage of commonly available acoustic calibrators
with a ½”
cavity. The instrument is factory calibrated with the supplied microphone for the standard environmental
conditions. Because the microphone sensitivity is a function of the temperature, ambient pressure and
humidity, the absolute calibration of the measurement channel should be performed locally. The instrument
performs the acoustic calibration automatically, when the calibrator is placed over the microphone (first
remove the windshield). The calibrator level is automatically detected and the calibration procedure is
started.
The user simply has to press
<ENTER>
key to confirm the calibration results. Calibration is only
allowed in the stopped mode. A sound measurement cannot be in progress while the calibration is being
performed.
Notice:
It is advised to perform an acoustic calibration of the instrument each time before
and after the measurement run. A single calibration at the start of each day of use is usually sufficient for
most regulations.
Notice:
The calibration factor is always added to the results in the Dose Meter or 1/1 Octave
analysis mode.
Notice:
The manufacturer’s recommended factory calibration interval is every 12 months for
this instrument to be confident in its continuing accuracy and compliance with the international specifications.
Please contact your local SVANTEK distributor for further details.
To calibrate the instrument manually the user has to enter the Calibration menu.
1. Adjust the actual calibration level of the calibrator to be used with the
<SCROLL>
and
<PROFILE>
keys
Figure 4-7
Calibration menu
2. Attach the acoustic calibrator,
SV 30A
,
SV 31
,
SV 34
,
B&K 4231
(or equivalent 114 dB / 1000 Hz)
carefully yet tightly over the microphone of the instrument. The presence of the calibrator will be
detected automatically
Notice:
It is also possible to use an electro-mechanical pistonphone, which generates the
signal (ca 124 dB) or different type of acoustic calibrator dedicated for ½” microphones with an
alternative output level such as 94 dB at 1 kHz. In any case, before starting the calibration
measurement, the user has to set the level of the signal generated by the given calibrator (Level
position), which is stated in the calibration certificate of the unit (the default expected value of the
Calibration Level set by the manufacturer of
SV 104
is equal to 114 dB).
