General Tools and Instruments DSM403SD - Manual (Page 8)

3. To switch from fast time weighting (the meter’s default setting) to slow time
weighting, press the SET button, which has the term “Fast/slow” stenciled below it.
Once you have set these three parameters (or kept the meter’s default settings), you are
ready to make sound level measurements.
4. To make a sound level measurement, point the condenser microphone at the top of the
meter in the direction of the sound source. The display will show its volume, in dB units.
Whenever the meter is in measurement mode, you can turn off the backlight (which is on
by default) by briefly pressing (but not holding) the POWER/ESC button. To reactivate the
backlight, briefly press the button again.
Whenever the meter is in measurement mode, you can also check the current date and
time by pressing and holding the ▲ button (which has the words “Time check” stenciled
below it). Doing so causes the date and time settings to appear briefly in that order at the
lower left of the display.
HOLDING AND STORING MEASUREMENTS
1. To hold a measured value, press the HOLD/NEXT button during the measurement.
Doing so will cause the word “HOLD” to appear at the top of the display. Pressing the
HOLD/NEXT button again releases the hold.
2. To hold a maximum reading, press the LOGGER button (which has the words “Peak
Hold” stenciled below it) while not in recording mode. The word “PEAK” will appear on
the top line of the display. To release the hold, press the LOGGER button again.
3. To record and recall readings, press the REC/ENTER button while making measure -
ments. This will make the term “REC” appear at the top of the display. Pressing the
REC/ENTER button again, briefly, will make the term “MAX” appear to the right of
“REC” and switch the display to the maximum value stored in memory during the current
recording session. Pressing the REC/ENTER button again, briefly, changes the term at
the right of “REC” to “MIN” and switches the display to the minimum value stored during
the current session.
4. To exit recording mode, press the REC/ENTER button and hold it for at least three
seconds, until the term “REC” disappears from the top line of the display. The display will
then revert to showing real-time readings.
AUTOMATIC VS. MANUAL DATA LOGGING
The DSM403SD can automatically log data at a user-selected sampling period from
1 second to 3,600 seconds (one hour). To view the sampling time that the instrument has
been set up to use, press and hold the ▼ button (which has the words “Sampling check”
stenciled below it) once. The lower readout of the display will briefly show the term “SP-t”,
followed by the sampling time in seconds. To change the sampling time, perform Step 7 of
the Setup Instructions.
Before entering data logging mode, remember to disable the meter's Auto Power Off
function. To do so, enter Setup mode (as explained in the Setup Instructions on pages 5 and
6) and select “no” during Step 5.
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