Digital Sound Level Meter
These instructions are intended for users without
any specific technical knowledge . Please read the
instructions carefully prior to operation and keep
them for later reference . All operating elements
and connections described can be found on the
fold-out page 3 .
1 Operating Elements
and Connections
1 Measuring microphone with windshield
2 Display
3 Key Lo / Hi for selecting the range
lower range 35 – 100 dB = basic setting after
switching on; on the left side of the display
"Lo" (low) is indicated
upper range 65 – 130 dB; on the left side of
the display "Hi" (high) is indicated
4 Key S / F for selecting the dynamic measuring
mode for sound levels changing fast (basic
setting; on the right side of the display "F" is
indicated) and for sound levels changing slowly
(indication "S")
5 Trimming control for calibrating the indication
to 94 dB; for this purpose, set the sliding switch
(9) to the position "CAL"
6 Key MAX for switching on or off the measure-
ment of the maximum level; with the function
switched on, "MAX HOLD" is indicated at the
left top of the display
7 3 .5 mm jack, output for the amplified micro-
phone volt age and a DC voltage proportional
to level (see chapter 6)
8 Key HOLD for holding the present value meas-
ured; with the function switched on, "DATA
HOLD" is shown at the top of the display
9 Sliding switch
OFF = meter switched off
A =
weighting filter switched on; the meas-
urement corresponds to the auditory
sensation of the human ear
C =
filter switched off; the measurement
corresponds to the physical sound level
CAL = calibration of the indication to 94 dB
with the trimming control (5)
10 Threaded jack (6 .3 mm /¼") for mounting the
meter on a stand
11 Battery compartment cover
6
2 Safety Notes
This unit corresponds to all relevant directives of
the EU and is therefore marked with
•
The meter is suitable for indoor use only . Protect
it against dripping water and splash water, high
air humidity, and heat (admissible ambient tem-
perature range 0 – 40 °C) .
•
For cleaning only use a dry, soft cloth; never use
chemicals or water .
•
No guarantee claims for the unit and no liability
for any resulting personal damage or material
damage will be accepted if the unit is used for
other purposes than originally intended, if it is
not correctly con nected, operated or not repaired
in an expert way .
If the unit is to be put out of operation
definitively, take it to a local recycling plant
for a disposal which is not harmful to the
environment .
3 Applications
The SM-2 serves for sound level measurement .
The meter allows to determine e . g . the frequency
response of an audio system, the efficiency and the
sound radiation of speakers, or the noise level in
rooms . For taking into account the auditory sen-
sation of the human ear, a weighting filter can be
switched on .
4 Operation
1) Switch on the meter with the sliding switch (9)
[position "A", "C", or "CAL"] .
2) An indication is displayed (2) . If not, insert a 9 V
battery . For this purpose, remove the battery
compartment cover (11) . Connect the battery
contacts to the battery, insert the battery in the
compartment, then close the cover .
If "BAT" is displayed at the left bottom, the
battery is exhausted and must be replaced .
3) For mounting the unit on a stand, the threaded
jack (6 .3 mm /¼") [10] can be used .
4) Always switch off the unit after operation, other-
wise the battery will be consumed unnecessarily:
Set the sliding switch (9) to the position "OFF" .
If the meter is not used for a longer period,
the battery should be removed to prevent dam-
age to the unit in case of battery leakage .
Never put batteries in the household
waste . To protect the environment, always
take them to a special waste disposal, e . g .
collection container at your retailer .
.