A new screen is displayed :
➢
Check that the reference value
Ref
: corresponds to that of the used calibrator and the value
free-field correction C.Cl (0,0 dB for the sound level meter).
➢
Place the running calibrator on the microphone.
➢
Move the cursor with arrow keys on
LCF.
The instrument automatically adjusts the gain of the channel to obtain the coincidence of the levels
displayed in Ref and LCF.
➢
When measurement is stabilized, a pictogram
Cal.
appears to validate through
OK
key.
At this moment the correction value of the gain and calibration date are memorized and visible for the
next calibration.
➢
Quit calibration function par with key .
Note :
This correction can not exceed
+/- 2 dB
. If the correction exceeds
+/- 2 dB
, the coincidence values in
Ref
and
LCF
is not
obtained. Reasons of this difference shall be identified
(defective microphone,
level value of the calibrator not adapted...).
Modification of the reference value
The reference preset value during manufacturing process shows that we use calibrator with rated value of 94 dB at 1000 Hz.
If the proposed reference is not the one of the available calibrator, follow the instruction below :
➢
Move the cursor on
Ref
. With arrow keys . Adjust to the desired value dB per dB with scrolling knob key .
This new value is memorized until the next change.
9.4 Maintenance
The sound level meter conception allows a reduced maintenance which consists in changing batteries and cleaning the instrument with
a slightly cloth. A particular attention must be paid to the microphone sensor, which is the element the most sensitive of the
metrological chain.
9.5 Regular checking
Like most measuring instruments, it is strongly recommended to regularly control and calibrate DB200
instrument. Return to the
manufacturer each year will provide necessary metrological traceability.
9.6 Change batteries
➢
Turn off the sound level meter.
➢
Return the instrument.
➢
Open the back hatch.
➢
Keep off the 3 batteries and insert the 3 new batteries of type 1.5 V / AAA-LR3 inside. Respect meaning of batteries.
➢
Close the back hatch.
9.7 Replace the batteries with a battery pack
According to the frequency of use of the instrument, it is sometimes better to replace batteries power by a rechargeable Li-ion battery.
The battery life increases to nearly 30 hours of continuous operation.
➢
Turn off the sound level meter.
➢
Remove the battery pack located inside the housing and disconnect the associated connector.
➢
Connect the battery respecting its insertion direction (mechanical keying of security).
27
Directions for use and sound level meter maintenance
Calibration
