AVSL 600.652 SOUND LEVEL METER - Manual (Page 4)

(If the C-Weighted level is much higher than the A-Weighted level, then there is a large amount of
low-frequency noise)
⑥ Time weighting select button F/ S
F (fast response): for normal measurements (fast varying noise)
S (slow response): for checking average level of fluctuating noise
⑦ Level range select button Lo/Hi
Lo: 30~100dB; Hi: 60~130Db
When “OVER” is indicated, the ranges switch to another range for measurement.
⑧ MAX/ Hold button MAX/HOLD
The max. Hold position is used to measure the maximum level of sounds. The maximum measured
level is up dated continuously. Press once again the button, will release the hold and allow a further
measurement. Data Hold button: Press and hold the Button for over 2 second to turn on or off data
hold function. The hold function freezes the reading in the d isplay.
⑨ Microphone
1/2 inch Electret Condenser microphone
⑩ Battery Cover
V. Measurement Preparation
(1) Battery loading
Remove the battery cover on the back and put in one 9V Battery.
(2) Battery Replacement
When the battery voltage drops below the operating voltage, mark “BAT” appears. If it appears,
battery should be replaced with new one.
VI. Operating Precautions
(1) Wind blowing across the microphone would bring additional extraneous noise.
Once using the instrument in the presence of wind, it is a must to mount the windscreen to not pick
up undesirable signals.
(2) To achieve more accurate measurement, use an extension cable to separate the Microphone from
the main body so that the effect of unexpected sound reflection can be eliminated.
(3) Calibrate the instrument before operation if the instrument was not in use for a long time or operated
at bad environment.
(4) Do not store or operate the instrument at high temperature and high humidity environment.
(5) Keep microphone dry and avoid severe vibration.
(6) Please take the battery and keep the instrument in low humidity environment. When not in use.
VII. Measurement
(1) Open battery cover and install a 9-volt battery in the battery compartment.
(2) Turn on power and select the desired response Time and weighting. If the sound source consists of
short bursts or only catching sound peak, set response to FAST. To measure average sound, use the
slow setting.
Select A- weighting for general noise sound level and C-weighting for measuring sound level of
acoustic material.
(3) Select desired Level
(4) Hold the instrument comfortably in hand or fix on tripod and point the microphone at the suspected
noise source, the sound pressure level will be displayed.
(5) When MAX (maximum hold) mode is chosen. The instrument captures and holds the maximum
noise level for a long period using any of the time weightings and ranges.
(6) When HOLD (data hold )mode is chosen.The hold function freezes the reading in the display. Press
the HOLD button momentarily to activate or to exit the HOLD function
(7) Turn OFF the instrument and remove and remove battery when not in use.