GVDA Digital Sound Level Meter User Manual

1. Introduction

The GVDA Digital Sound Level Meter is designed to accurately measure environmental sound levels in various settings, including factories, workshops, schools, residences, offices, and traffic areas. It is an essential tool for noise engineering, product quality control, and health prevention. This device also features the capability to measure ambient temperature and humidity.

2. Safety Precautions

• Always read this manual carefully before using the instrument and retain it for future reference.
• Avoid storing or operating the instrument in areas of high humidity or extreme temperatures.
• Keep the meter and microphone dry to prevent damage.
• Avoid severe vibration or impact to the device.
• Remove the batteries if the meter will be stored for extended periods to prevent battery leakage.
• Do not use corrosive agents or solvents for cleaning. Wipe the shell regularly with a mild detergent or a damp cloth.

3. Product Overview

3.1 Components

The sound level meter consists of the following main components:

• Microphone: Electret condenser microphone for sound detection.
• Sponge Ball (Windscreen): Used to cover the microphone to reduce wind noise.
• Display: LCD screen showing measurements and indicators.
• Power Key: To turn the device on or off.
• MAX/MIN Key: For maximum and minimum value functions.
• °C/°F Key: To switch temperature units.
• H/☀ Key: For Data Hold and Backlight functions.
• F/S Key: For Fast/Slow time weighting selection (and A/C weighting for GD151B).

Image: Detail of the condenser microphone with the sponge ball (windscreen).

3.2 Display Screen Symbols

4. Setup

4.1 Battery Installation

The GVDA Sound Level Meter requires 3 x AAA batteries (not included). To install or replace batteries:

1. Unscrew and open the battery compartment cover located on the back of the device.
2. Remove any old batteries if present.
3. Insert three new 1.5V AAA batteries, ensuring correct polarity (+ and - marks) as indicated in the compartment.
4. Close the battery cover and fasten the screws to secure it.

Image: View of the battery compartment with AAA batteries.

5. Operation

5.1 Turning On/Off

• To turn on: Press the ⏻ button.
• To turn off: Press the ⏻ button again.

5.2 Noise Measurement

1. Open the protective cover of the microphone. If applicable, use the supplied windscreen (sponge ball) to cover the microphone to minimize wind noise.
2. Turn on the meter by pressing the ⏻ button. The meter will automatically display sound pressure level, ambient temperature, and humidity.
3. Hold the meter with the microphone facing the sound source you wish to measure.
4. Read the measured values from the display.

Image: The sound level meter displaying Decibel, Temperature, and Humidity readings during noise measurement.

5.3 MAX/MIN Function

• Press the MAX/MIN button to activate the maximum and minimum value display.
• The display will cycle between the current, maximum (MAX), and minimum (MIN) sound levels.
• Press and hold the MAX/MIN button for approximately 2 seconds to exit this function and return to normal measurement.

5.4 Data Hold

• Press the H/☀ button to freeze the current reading on the display. The 'H' symbol will appear.
• Press the H/☀ button again to release the data hold function and resume live measurement.

5.5 Fast/Slow Time Weighted Selection

The F/S button allows you to choose between Fast (125 ms) and Slow (1 sec) time weighting:

• FAST (125 ms): Ideal for capturing noise peaks and rapidly changing noise levels.
• SLOW (1 sec): Suitable for monitoring sound sources with consistent noise levels and averaging out fluctuating noise.

The selected mode ('FAST' or 'SLOW') will be indicated on the display.

Image: Visual guide for Fast/Slow Time Weighted Selection, MAX/MIN, and Data Hold functions.

5.6 A/C Weighted Selection (GD151B Only)

For model GD151B, you can switch between A and C frequency weighting:

• Press and hold the F/S button for approximately 2 seconds to toggle between A-weighting and C-weighting.
• A-weighting: Simulates the human ear's response to sound, commonly used for ambient noise measurement.
• C-weighting: Provides a flatter response, suitable for measuring mechanical noise or peak sound levels.

Image: Illustrates the difference between A-weighting (GD151A) for ambient noise and A/C-weighting (GD151B) for mechanical noise.

5.7 Backlight

• To enable or disable the backlight, press and hold the H/☀ button for more than 2 seconds.

5.8 Auto Power Off

The meter has an automatic power-off function enabled by default. If there is no operation for 10 minutes, the meter will automatically shut down to conserve battery life. The ⏻ symbol will be displayed when this function is active.

• To disable auto power off: Before turning on the instrument, press and hold the ⏻ button. While still holding, press the power button to turn on the instrument. Release the ⏻ button after the meter turns on. The ⏻ symbol will no longer be displayed.
• To restore auto power off: Restart the instrument after it has shut down.

Image: The meter illustrating the 10-minute auto power off feature.

5.9 Temperature Unit Selection

• Press the °C/°F button to toggle the temperature unit between Celsius (°C) and Fahrenheit (°F).

6. Maintenance

6.1 Battery Replacement

When the low battery symbol appears on the display, replace the batteries as described in Section 4.1.

6.2 Cleaning

To maintain the instrument and prevent damage:

• Do not use corrosive agents or strong solvents to clean the meter's casing.
• Regularly wipe the exterior of the device with a mild detergent or a damp, soft cloth.

7. Troubleshooting

• Device not turning on: Ensure that 3 x AAA batteries are correctly installed with the proper polarity and are not depleted.
• Inaccurate readings: Check for environmental factors like strong winds (use the sponge ball), extreme temperatures, or high humidity. Ensure the microphone is clean and unobstructed.
• Display issues: If the display is dim or flickering, replace the batteries.
• No C-weighting option: The C-weighting feature is only available on the GD151B model. GD151A only supports A-weighting.

8. Specifications

9. User Tips

• Battery Reminder: The device does not come with batteries. Ensure you have 3 x AAA batteries ready for immediate use.
• A-Weighting vs. C-Weighting: For general ambient noise measurements that mimic human hearing, use A-weighting. For analyzing mechanical noise or peak sound levels, especially if you have the GD151B model, utilize C-weighting. This can be useful for comparing speaker power or different noise sources.
• Ease of Use: Users find this equipment highly sensitive and easy to operate, making it suitable for various applications.
• Calibration: While the device is factory calibrated, for highly critical applications, consider professional calibration periodically.

10. Warranty and Support

For warranty information, technical support, or service inquiries, please contact the manufacturer or your point of purchase. Keep your purchase receipt as proof of purchase.

11. Compliance

This device complies with CE and FCC certification standards.

12. Additional Resources

A detailed user manual in PDF format is available for download. This document provides comprehensive instructions and diagrams for your GVDA Sound Level Meter.

View User Manual (PDF)