1. Product Overview
The BENETECH GM1356 is a digital sound level meter designed for measuring sound levels in various environments. It features a wide measurement range, A/C frequency weighting, fast/slow time weighting, and a USB interface for data analysis.
1.1 Key Features
- Wide measurement range: 30~130dBA, 35~130dBC
- Accuracy up to ±1.5dB
- Designed according to IEC PUB 651 TYPE2 and ANSI S1.4 TYPE2 standards
- Modern, compact, portable design
- Easy to use interface
- Frequency weighting characteristic: A & C
- Time weighting characteristic: Fast & Slow
- AC/DC output for external devices
- Bar graph indication on display
- Equipped with a sponge ball to filter out unwanted signals
- Max reading hold function
- USB interface for PC connection
- Includes analysis software
- Automatic power off function
- Overload indication: OVER/UNDER
- Automatic backlight display
- Low battery indication
- CE/ROHS/FCC approved
1.2 Package Contents
Upon unpacking, please ensure all items listed below are present and in good condition:
- 1 x BENETECH GM1356 Digital Sound Level Meter
- 1 x English User Manual
- 1 x CD Software
- 1 x USB Cable
- 1 x AC Output Wire
- 1 x Carry Box
- 1 x Color Box
Note: Batteries are not included in the package. Shipping companies do not accept liquids, powders, or dry batteries.
Figure 1: GM1356 Sound Level Meter and Accessories
2. Safety Information
Please read and understand all safety instructions before operating the device. Failure to follow these instructions may result in electric shock, fire, or damage to the device.
- Do not attempt to open or modify the device.
- Keep the device away from water and other liquids.
- Do not operate the device in explosive atmospheres.
- Ensure batteries are inserted correctly according to polarity markings.
- Remove batteries if the device will not be used for an extended period.
- Avoid dropping the device or subjecting it to strong impacts.
3. Getting Started
3.1 Battery Installation
- Locate the battery compartment on the back of the device.
- Slide open the battery cover.
- Insert four (4) AA 1.5V batteries, ensuring correct polarity (+/-).
- Close the battery cover securely.
Figure 2: Battery Compartment Location
3.2 Software Installation and PC Connection
- Insert the provided CD software into your computer's CD-ROM drive.
- Follow the on-screen instructions to install the analysis software.
- Connect the GM1356 to your computer using the supplied USB cable. The USB port is located on the side of the device.
- Launch the installed software to begin data analysis and logging.
Figure 3: Side Ports (USB, AC/DC Output)
4. Operation
4.1 Powering On/Off
- Press the Power button (
) to turn the device on. - Press and hold the Power button to turn the device off.
- The device features an auto power-off function to conserve battery life.
4.2 Basic Measurement
- Ensure the sponge ball is attached to the microphone to filter out wind noise and other unwanted signals.
- Point the microphone towards the sound source.
- The current sound level will be displayed on the digital screen and indicated by the bar graph.
Figure 4: Device Front View and Display
4.3 Frequency Weighting (A/C)
- Press the A/C CLEAR button to toggle between A-weighting and C-weighting.
- A-weighting: Simulates the human ear's response to sound, commonly used for environmental noise measurements.
- C-weighting: Provides a flatter response, suitable for measuring peak sound levels or noise from machinery.
4.4 Time Weighting (Fast/Slow)
- Press the F/S RECORD button to toggle between Fast and Slow time weighting.
- Fast: Responds quickly to changes in sound level, suitable for measuring impulsive or rapidly changing noise.
- Slow: Provides an averaged reading, suitable for measuring steady noise levels.
4.5 Max Reading Hold
- Press the MAX CLOCK button to activate the Max Hold function. The display will show the maximum sound level recorded since the function was activated.
- Press the button again to exit Max Hold.
4.6 AC/DC Output
- The device provides AC and DC output jacks on the side.
- AC Output: 0.707Vrms at FS output impedance approx. 600ohm.
- DC Output: 100mV/dB, output impedance approx. 100ohm.
- These outputs can be used to connect the sound level meter to external recording devices, data loggers, or analyzers.
Video 1: Demonstration of the BENETECH GM1356 Digital Sound Level Meter in use.
5. Maintenance and Care
5.1 Cleaning
- Wipe the device with a soft, dry cloth.
- Do not use abrasive cleaners or solvents.
- Keep the microphone and sponge ball clean and free from dust.
5.2 Battery Replacement
- When the low battery indicator appears on the display, replace all four AA batteries promptly.
- Refer to section 3.1 for battery installation instructions.
5.3 Storage
- Store the device in its carry box when not in use to protect it from dust and physical damage.
- Storage conditions: -10°C to 60°C (14°F to 140°F) with 10% to 70% Relative Humidity (RH).
- Remove batteries if storing for extended periods to prevent leakage.
6. Specifications
Figure 5: Detailed Product Specifications
| Parameter | Value |
|---|---|
| Measuring Range | 30dBA~130dBA, 35~130dBC |
| Accuracy | ±1.5dB |
| Frequency Range | 31.5Hz~8.5KHz |
| Frequency Weighting | A/C |
| Digital Display | 5 digits |
| Resolution | 0.1dB |
| Measuring Level | 30~130, 40~90, 50~100, 60~110, 80~130 |
| Linearity Range | 50dB/100dB |
| Sample Rate | 2 times/second |
| AC Output | 0.707Vrms at FS output impedance approx. 600ohm |
| DC Output | 100mV/dB, output impedance approx. 100ohm |
| Microphone | 1/2 inch electret condenser microphone |
| Power Supply | 4 x AA 1.5V Batteries (Not included) |
| Operating Condition | 0~40°C (32~104°F), 10~80% RH |
| Storage Condition | -10~60°C (14~140°F), 10~70% RH |
| Weight | 308g (including battery) |
| Dimension | 70 × 35 × 256mm |
7. Troubleshooting
If you encounter issues with your GM1356, please refer to the following common problems and solutions:
- Device does not power on: Check battery installation and ensure batteries are not depleted. Replace with fresh batteries if necessary.
- No reading or incorrect reading: Ensure the microphone is pointed correctly and not obstructed. Check the selected frequency and time weighting settings.
- "OVER" or "UNDER" indication: The sound level is outside the measurable range. Adjust your position relative to the sound source or consider if the environment is too loud/quiet for the device's capabilities.
- Software connection issues: Verify the USB cable is securely connected to both the device and the computer. Reinstall the software if connection problems persist.
8. Warranty and Support
The BENETECH GM1356 Digital Sound Level Meter comes with a 1-year guarantee from the date of purchase.
For further detailed instructions, technical support, or warranty claims, please refer to the official user manual PDF available at: BENETECH GM1356 User Manual (PDF).
