MONACOR SM-2 Digital Sound Level Meter Instruction Manual
- May 16, 2024
- MONACOR
Table of Contents
Digital Sound Level Meter
SM-2
Bestellnummer • Order Number 0291870
INSTRUCTION MANUAL
SM-2 Digital Sound Level Meter
Digital
Sound Level Meter
These instructions are intended for users with basic knowledge of audio
technology . 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 .
Operating Elements and Connections
-
Measuring microphone with windshield
-
Display
-
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
-
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”)
-
Trimming control for calibrating the indication to 94 dB; for this purpose, set the sliding switch (9) to the position “CAL”
-
Key MAX for switching on or off the measurement of the maximum level; with the function switched on, “MAX HOLD” is indicated at the left top of the display
-
3.5 mm jack, output for the amplified microphone volt age and a DC voltage proportional to level (see chapter 5.1)
-
Key HOLD for holding the present value measured; with the function switched on, “DATA HOLD” is shown at the top of the display
-
Sliding switch
OFF = meter switched off
A = weighting filter switched on; the measurement 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) -
Threaded jack (6 .3 mm / ¼”) for mounting the meter on a stand
-
Battery compartment cover
Important Notes
The device corresponds to all relevant directives of the EU and is therefore
marked with ****.
The device corresponds to the relevant UK legislation and is therefore marked
with UKCA.
- The meter is suitable for indoor use only . Protect it against dripping water and splash water, high air humidity, and heat (admissible ambient temperature range 0 – 40 °C) .
- For cleaning only use a dry, soft cloth; never use chemicals or water .
- No guarantee claims for the device and no liability for any resulting personal damage or materialdamage will be accepted if the device is used for other purposes than originally intended, if it is not correctly con nected, operated or not repairedin an expert way.
**** If the device is to be put out of operation definitively, dispose of the device in accordance with local regulations.
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 sensation of the human ear, a
weighting filter can be switched on
Operation
-
Switch on the meter with the sliding switch (9) [position “A”, “C”, or “CAL”] .
-
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 .
**** Never put batteries in the household waste . Always dispose of the batteries in accordance with local regulations . -
For mounting the device on a stand, the threaded jack (6 .3 mm / ¼”) [10] can be used .
-
Always switch off the device after operation, otherwise the battery will be consumed unnec-essarily: 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 damage to the device in case of battery leakage.
Measuring the Sound Level
-
For a precise measurement, check the calibrationbeforehand: Set the sliding switch (9) to theposition “CAL” . 94 .0 dB should be displayed . If not, adjust the trimming control (5) by means of a screw driver so that 94 .0 dB is displayed .
-
For measuring the sound level in accordancewith the auditory sensation of the human ear, set the sliding switch to the position “A” . In the position “C”, the physical sound level is measured (linear).
-
For measuring, hold the meter horizontallywith the microphone (1) pointing to the sound source .
-
After switching on, the lower measuring range 35 – 100 dB is always selected . On the left side of the display “Lo” is indicated .
When measuring values exceeding 100 dB, “OVER” is indicated at the right bottom of the display . In this case, switch to the upper range 65 – 130 dB with the key Lo / Hi (3) . Instead of“Lo”, “Hi” is displayed .
When measuring values below 65 dB in the upper range, “OVER” is also indicated . In this case, return to the lower range with the keyLo / Hi . -
After switching on, the dynamic measuringmode is set to sound levels changing fast . On the right side of the display, “F” (fast) is indicated . For measuring sound levels changingslowly, switch to the second mode with thekey S / F (4) . The indication changes from “F”to “S” (slow).
-
For holding the present value measured, press the key HOLD (8) . At the top of the display“DATA HOLD” is indicated . To return to the present value measured, actuate the key HOLD once again .
-
To determine the maximum level occurring, pressthe key MAX (6) . At the top of the display “MAXHOLD” is indicated . Now the level value of the highest volume occurring after actuating the keyMAX will be held . For switching off the function,actuate the key MAX once again .
Notes:
a The sound level measured largely depends on the distance of the meter
from the sound source . When measuring, observe a defined distance (e . g . 1
m for speaker measurements) or state the distance at which the measurement was
made .
b The level measured also depends on the angle to the sound source . It may be
necessary to measure the levels at different angles (but at the same distance)
to determine the sound radiation be haviour of the sound source .
5.1 Picking up a Microphone Signal or
a DC Voltage proportional to Level
At the output jack (7), the following voltages are pres ent to be picked up
for a control depending on the level or for further analysis . For this
purpose, connect a 3-pole 3 .5 mm plug to the jack .
Signals at the 3 .5 mm plug connected tip – body:
microphone signal
in the lower measuring range “Lo” 38 mV/dB
in the upper measuring range “Hi” 8 .3 mV/dB
impedance 100 Ω ring – body:
DC voltage proportional to level 10 mV/dB impedance 100 Ω
Specifications
Display: ………………. 17 mm LCD, 3½ digits Measuring ranges
Lo (low):………………… 35 – 100 dB
Hi (high): …………………. 65 – 130 dB
Resolution: ……………………………0.1 dB
Accuracy: …………………… ±1.5 dB at 94 dB, 1 kHz
Frequency range: …………………. 31.5 – 8000 Hz
Level weighting: …………………. A or C
Type of microphone: . electre…………t microphone
Output jack (signals at the plug)
tip – body: ……………………. microphone signal, impedance 100 Ω
ring – body: . DC voltage proport………………ional to level 10 mV/dB, 100 Ω
Ambient temperature: . 0 – ………..40 °C
Power supply: ……………… 1 × 9 V battery
Dimensions, weight: . 63 × ………….253 × 30 mm, 250 g
Subject to technical modification .
All rights reserved by MONACOR® INTERNATIONAL GmbH & Co. KG. No part of this
instruction manual may be reproduced in any form or by any means for any
commercial use.
© MONACOR INTERNATIONAL
All rights reserved
A-0180.99.05.06.2023
Importer: Epic Audio Ltd, Unit 9 Apollo Park
Station road, Long Buckby, NN6 7PF
United Kingdom, Company Registration: 13878247
****MONACOR INTERNATIONAL GmbH & Co. KG
Zum Falsch 36, 28307 Bremen
Germany