General Tools DSM8921 User Manual

Digital Sound Level Meter

Model: 8921
8922

INTRODUCTION

Your digital sound level meter provides
automatic or manual ranging in six
meas-urement ranges from 30 to 130dB.
The unit meets ANSI S1.4 and IEC 651
Type 2 standards, and features 0.1dB
resolution.

A background noise absorber permits
you to measure sound levels accurately
even in the presence of high background
noise.

The meter allows you to select between
fast and slow response times and A and
C weighting. A maximum hold function
is provided.

Jacks on the meter provide both AC and
DC analog output, while an RS-232
interface allows you to use an optional
cable to capture sound level data on a
PC.

FUNCTIONS:

1. Selecting A & C weighting.

2. Selecting the response time.

3. Freezing the maximum sound
level reading.

4. Recording the maximum and
minimum measurements.

5. Using the backgound noise
absorber.

6. Selecting Automatic and manual
ranging.

7. Automatic shut off.

8. Easy to replace battery.

FRONT PANEL DESCRIPTION

1 MICROPHONE
2 LCD DISPLAY
3 ON/OFF
4 REC

5 MAXHLD

6 C/A

7 BA MODE

8 F/S

9 DOWN

10 UPPER

11 DC 9V
12 CAL
13 AC OUT
14 DC OUT
15 RS232
16 BACKLIT

The meter will display all segments
when it is first turned on. Though you

might seen SEL, Leq, DOSE, PEAK....

These are not available for the meter
you purchased, please contact the
store or the place you purchased for
further models with these additional
functions.

- Power button

- Records sound level

readings

- Freezes the maximum
sound level digital
reading

- A/C frequency
weighting selector

- Background noise
absorber

- Fast/Slow response
selector

- Adjusts the
measurement range

- Adjusts the
measurement range

- DC adapter jack

- Calibration screw

- AC analog output jack

- DC analog output jack

- RS-232 output jack

- Back light

(Model 8922 only)

FRONT PANEL DIAGRAM

16

0

MEASURING SOUND LEVELS

Sound levels are displayed both digitally
and in a bar graph. The digital display
is updated every 160ms, while the bar
graph is updated every 40ms.

Press the ON/OFF key to turn the
meter on. The unit will first display
the full screen and then count down
to zero.(See Fig. 1)

90dB

50dB

90

+1

0

2

+

0

+40

+

+30

Fig.1

The meter will now begin measuring
the current sound levels.(See Fig.2)

+30

+20

0

+1

50

+4

0

+50

Fig.2

50

SPL

Point the microphone toward the source
of the sound to be measured.