Benetech GM1357 User manual

MODEL: GM1357
Digital Sound Level Meter
Operation Manual
A. Introduction
This equipment has been designed to meet
measurement requirement of Safety Engineers,
Health, Industrial Safety office and Sound
Quality control in various environment which
include factory, office, traffic, family and audio
system
This equipment has the following functions:
1.It is design according to IEC651 TYPE2 &
ANSI S1.4 TYPE2
2.Accuracy up to ±1.5dB
3.Measurement range: 30dB – 130 dB
4.With two equivalent weighted sound pressure
levels, A and C
5.Fast & Slow dynamic characteristic modes
6.AC and DC output for frequency analyzer level
recorder, FFT analyzer, Graphic recorder etc.
B. Safety Notice:
(Page 1) (Page 2) (Page 3)
1) Below 2,000 Meters in height
2) Humidity <80% RH
3) Operation temperature: 0-40C.
Operation Environment Condition:
Maintenance:
Use dry cloth to clean the unit but never with any
solvent.
Figure 1
Please use a Standard Acoustic Calibrator.
1. Make the following settings:
1.1 Equivalent weight: SPL (dBA)
1.2 Time weighting: FAST
1.3 Level range: 60 to 110 dB
1.4 Measurement mode: MAX function disable
C. Calibration Procedures:
3 Turn on the Calibrator and adjust the potentiometer
inside the battery compartment of the unit
(shown in the Figure1), until the LCD display the
desire level (94 dB)
*Our products are all well calibrated before shipment.
(Recommended recalibration cycle:1 Year.)
2 Insert the microphone carefully into the ½ inch
hole of the Calibrator.
D. Name and functions (Figure 2)
1. Electret Condenser Microphone.
2. LCD Display.
3. Power switch
4. Level range control switch:
30dB~80dB; 50dB~100dB 60dB~110dB;
80dB~130dB; 30dB~130dB;
5. Maximum value hold switch. (MAX)
6. Frequency weighting select switch.
A: A weighting for general sound level measurements.
C: C weighting for checking the low frequency content
of noise.
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E. LCD Display (Figure 3)
1). Level range.
2). Instantaneous sound pressure level.
3). Low battery mark.
4). Maximum value is held during measuring.
5). Measuring value.
6). Measurement Unit.
7). Frequency weighting A/C.
8). Level range Bar graph.
9). Rang over.
10). Slow time weighting.
11). Fast time weighting.
12). Range under.
F. Pre-Operations:
1. Open the battery door and install 4pieces battery
into the battery compartment.
2. Cover the battery door.
3. When battery voltage drops below the operating
voltage, mark “ “ appears, Please replaced
with a new 9V battery. (Figure 4)
4. When the DC adapter is used, insert plug (3.5 )
of the adapter into the DC 6V connector
G. Operation
H. Caution
I. Specification
Measuring range 30dBA-130dBA, 35dBC - 130dBC
Accuracy ±1.5 dB ( 94 dB@1KHz )
Frequency range 31.5Hz – 8.5KHz
Linearity range 50dB/100dB
Frequency weighting A/C
Digital Display 4 digits
Resolution 0.1 dB
Sample rate 2Times/Second
Bar graph
50 dB scale at 1 dB step for monitoring
current sound pressure level display Sample
rate: 20Times/Second
Over Indication OVER/UNDER
AC Output 0.707 Vrms at FS outputimpendance
approx 600 ohm
DC Output 10 mV / dB output impedance approx 100
Time Weight FAST/SLOW
Microphone ½ Inch Electric Condenser Microphone
Max Hold MAX
Power supply 4*AA 1.5V alkaline cells or DC 6V
100mA (Maximum DC 9V)
Battery Life About 30hours (Alkaline Battery)
Self Calibration Time 3Second
Operating Condition 0~40 10~80%RH
Storage condition: -10~60 10~70%RH
Weight 308g (including battery)
Dimension 256x70x35mm
MADEINCHINA
(Page 5) (Page 6)(Page 4)
1. Turn on the unit
2. Standard the desired measuring range until the LCD
not display “ Under ” or “ Over “
3. If measure general noise sound level, please
selected dBA.
4. If the sound source consists of the shot brusts of only
catching sound peak, set response to FAST.
To measure average sound level, use the slow time
weight.
5. When MAX mode is chosen. The instrument
captures and hold the maximum noise level.
1. Do not operate the unit at high temperature and
Humidity environment.
2. Please take out battery from unit if not in use
for any extended period of time.
3. Once using the unit in the presence of wind,
it is a must to mount the windscreen to not
pick up undesired signals.
4. Below 200 feet in Height, Humidity 80%RH,
Temperature from 0 to 40 .
8. AC output terminal: 0.707 Vrms Corresponding
to each range step.
9. DC out put terminal: output 10 mV/ dB
10. Calibration control
11. External DC 6V power supply terminal.
12. Tripod mounting screw.
13. Windscreen.
Figure 4
Figure 3
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