ATP Instrumentation MT-901A User manual

User Manual
Mini Sound Level Meter
Please read this user manual thoroughly before using
this unit and keep it for your future reference.

1
Contents
1. Safety..................................................................1
2. Introduction..........................................................2
3. Specifications......................................................2
4. Meter Description................................................4
5. LCD Display Description.....................................6
6. Basic Operation..………………………..…………7
7. Operation Instructions.........................................7
8. Operation Precautions ........................................9
9. Calibration………………………………………….9
10. Accessories.......................................................9
1. Safety
Read the following safety information carefully before
attempting to operate the meter.
Use the meter only as specified in this manual;
otherwise, the warranty may be invalidated.
▲Environment conditions:
Altitude up to 2000 meters
RH≤90％（Non-Condensation）
Operating Temperature: -20～60℃

2
▲Maintenance
Repairs or servicing should only be performed
by ATP Instrumentation Ltd.
Wipe the unit with a dry soft cloth. Do not use
abrasives or solvents on this instrument.
▲Safety Symbol
Complies with EMC
2. Introduction
This Sound Level Meter is designed to meet the
measurement requirements of safety Engineers, Health,
Industrial safety offices and sound quality control in various
environments like factories, schools, construction sites etc.
Complies with IEC61672-1 CLASS2 Standard
Max/Min Measured Values
Data Hold
“A” Frequency Weighting
3. Specifications
Applied standard
IEC61672-1 CLASS2
Accuracy
±1.4dB
Frequency range 31.5Hz ～8KHz

3
Dynamic range 50dB
Measuring range 30dB ～130dB
Frequency weighting
dBA
Microphone
1/2 inch electret condenser
Display 3 1/2 digits
Resolution 0.1dB
Data update：0.5 sec
Max Hold MAX
Min Hold MIN
Data Hold HOLD
Auto power off
After approx. 15 minutes of
inactivity.
Power supply
One 9V battery, 006P or
IEC 6F22 or NEDA 1604.
Battery life at least 30 hours
Operating conditions
-20
℃
～60
℃
10％RH～90％RH
Storage conditions
-20
℃
～60
℃
10％RH～75％RH
Dimension(L*W*H) 144 x 55 x 38mm
Weight:
90g

4
4. Meter Description

5
(1) Wind muffler microphone cover
(2) Microphone
(3) LCD display
(4) Power ON/OFF button
(5) MIN/MAX and Data Hold button
(6) Tripod bush
(7) Battery compartment

6
5. LCD Display Description
Icon Function
LCD 3 1/2 digits
MAX Max value hold
MIN Min value hold
dBA Afrequency weighting（designed to reflect
the response of the human ear to noise）
HOLD Data hold
Low battery indication

7
6. Basic Operation
Open battery cover and install a 9-volt battery in the
battery compartment.
Close the battery compartment.
When the low battery icon " " appears, replace
the battery.
7. Operation Instructions
①Backlight & Power ON/OFF Function
Power ON：To turn the meter on, press & hold the " "
button for 1 second until the LCD is lit, then release
the button.
Power OFF：To turn the meter off, press & hold the " "
button for approx. 3 seconds until the LCD switches off,
then release the button.
Backlight：After turning the meter on, momentarily press the
" " button and the backlight will turn on/off. It will
automatically turn off after approx. 30 seconds of
inactivity.

8
DATA HOLD & MAX/MIN Function
HOLD: After turning the meter on, momentarily press the
" " button, "HOLD" icon will appear on the LCD,
and the current displayed value will be frozen. To
return from the held reading, press the button again.
MAX/MIN: Press & hold the " " button for at least 3
seconds until "MAX" icon appears on the LCD to view
the current MAX reading. Press the button again and
the "MIN" icon will appear to display the current MIN
reading. To exit the MAX/MIN mode, press & hold the
" " button for 3 seconds.
The meter will conduct measurement and select
measurement range automatically. Measuring level
range：30dB ～130dB.
Hold the meter in hand or use the tripod to affix the
meter in the desired location. The best measuring
distance is 1 to 1.5m away from the sound source to
the microphone.

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8. Operation Precautions
①Do not store or operate the meter in areas of high
temperature or humidity.
②Remove the battery when the meter is to be stored for
long periods of time to avoid battery leakage.
③Wind blowing across the microphone will affect the
noise measurement. Use the supplied wind muffler to cover
the microphone during applications involving turbulent air.
④Keep microphone dry and avoid severe vibration.
9. Calibration
Repairs, servicing or calibration should only be performed by
ATP Instrumentation Ltd.
10. Accessories
①User manual
②Wind Muffler

ATP Instrumentation Ltd
Tournament Way
Ashby-de-la-Zouch
Leicestershire
LE65 2UU
Sales: 01530 566 800 [e-mail]
Repair and Calibration: 01530 566 804 [e-mail]
www.atp-instrumentation.co.uk