1. Introduction
The GD-3306/3308 Combustible Gas Leak Detector is a highly sensitive and reliable instrument designed for detecting the presence of combustible gases. It accurately measures gas concentrations between 0 and 10000 parts per million (PPM).
The GD-3308 model indicates gas presence via a clear LCD display, showing precise PPM readings. The GD-3306 model utilizes five red LEDs to indicate different concentrations of gas. Both models feature a beeper function that operates much like a Geiger counter: it sounds rapidly with increasing concentrations of combustible gas (from 0 PPM to 3200 PPM) and continuously above 3200 PPM. Additionally, a vibration alarm is standard for both models.
This detector provides quick and precise gas leak locating, making it an essential tool for explosion prevention and ensuring safe working environments.
Image: CEM GD-3308 Gas Detector highlighting its compact design and key features.
2. Product Specifications
General Features
| Feature | GD-3306 | GD-3308 |
|---|---|---|
| Digital LCD Display | * | |
| Visible, Audible & Vibration Alarm | * | * |
| Highly Sensitive and Reliable | * | * |
| Pinpoint Small Leaks | * | * |
| Auto Zero | * | * |
| High Accuracy, Quick Response | * | * |
| 16-inch Flexible Probe with Replaceable Sensor | * | * |
| Auto Power Off | * | * |
Detailed Specifications
| Parameter | Value | GD-3306 | GD-3308 |
|---|---|---|---|
| Sensitivity | <50ppm (methane) | * | * |
| Range | 0～10000ppm (methane) | * | * |
| Response Time | <2 secs | * | * |
| Warm-Up Time | Approx. 40 secs | * | * |
| Audible Alarm | >75 db | * | * |
| Vibration Alarm | Standard | * | * |
| Probe Length | 16 inches | * | * |
| Visual Alert (GD-3306) | 5 Red LEDs: Gas Measuring Levels; Sensitivity Visual Alert | * | |
| Display Type (GD-3308) | LCD | * | |
| Audible Alert Description | Loud Audible Ticking Rate (w/Continuous Modulation Proportional to Gas Level) | * | * |
| Weight | 480g | * | * |
| Size (HxWxD) | 220mm x 62mm x 40mm | * | * |
| Material | Plastic | * | * |
| Origin | Mainland China | * | * |
Image: Detailed view of the GD-3308's display and controls.
3. Accessories List
The following items are typically included with your GD-3308 Combustible Gas Leak Detector:
- GD-3308 Combustible Gas Leak Detector Unit
- Gift box with carrying case
- User Manual (this document, and a PDF version)
Note: A 9V battery is required for operation but is NOT included due to international transportation regulations.
4. Setup and Operation
4.1. Setup
- Battery Installation: Open the battery compartment (usually located on the back or bottom of the device) and insert a fresh 9V battery, ensuring correct polarity. Close the compartment securely.
- Power On: Press the power button to turn on the device.
- Warm-Up: Allow approximately 40 seconds for the detector to warm up. During this period, the device performs internal checks and stabilizes the sensor.
- Auto Zero: The device features an auto-zero function. Ensure the detector is in a clean, gas-free environment during warm-up or when performing a manual auto-zero to establish a baseline reading.
4.2. Operation
- Positioning the Probe: Extend the 16-inch flexible probe towards the area where a gas leak is suspected. Move the probe slowly around pipes, fittings, and appliances.
- Interpreting Readings (GD-3308): The LCD display will show the concentration of combustible gas in PPM. Higher readings indicate a stronger presence of gas.
- Interpreting Readings (GD-3306): The five red LEDs will illuminate to indicate increasing gas levels. More illuminated LEDs signify higher gas concentrations.
- Audible Alarm: The built-in beeper will emit a ticking sound. The rate of ticking increases proportionally with gas concentration. Above 3200 PPM, the beeper will sound continuously.
- Vibration Alarm: The device will vibrate as an additional alert, especially useful in noisy environments.
- Pinpointing Leaks: Move the probe slowly to find the highest concentration reading or the most rapid alarm, which indicates the precise location of the leak.
For more detailed operational instructions, including advanced settings and calibration procedures, please refer to the official user manual PDF available at: GD-3308 User Manual (PDF).
Image: GD-3308 detector being used to check for leaks in an industrial setting.
5. Safety Precautions
- Always operate the device in well-ventilated areas to avoid false readings or hazardous conditions.
- Do not expose the sensor or the device to extreme temperatures, high humidity, or corrosive environments, as this may affect accuracy and device longevity.
- This device is intended for detection purposes only. Do not rely solely on this detector for critical safety decisions; always use it in conjunction with other appropriate safety measures and procedures.
- Do not attempt to open, repair, or modify the device. Unauthorized modifications can lead to malfunction, inaccurate readings, and void the warranty.
- Keep the device out of reach of children.
- Ensure the probe is clean and free from obstructions before and during use.
- In case of a detected gas leak, immediately follow your facility's or local emergency procedures.
6. Maintenance and Storage
6.1. Maintenance
- Cleaning: Wipe the device exterior with a soft, damp cloth. Do not use abrasive cleaners or solvents. Ensure no liquid enters the sensor or electronic components.
- Sensor Care: The flexible probe features a replaceable sensor. If you notice a decrease in sensitivity or consistent inaccurate readings, the sensor may need replacement. Refer to the PDF manual for sensor replacement instructions.
- Battery Replacement: Replace the 9V battery when the low battery indicator appears on the display (GD-3308) or when the device fails to power on or operate reliably.
6.2. Storage
- Store the detector in its original carrying case or a protective pouch to prevent damage.
- Keep the device in a cool, dry place, away from direct sunlight, extreme temperatures, and high humidity.
- For extended storage periods (e.g., more than one month), remove the 9V battery to prevent leakage and potential damage to the device.
7. Troubleshooting
If you encounter issues with your GD-3308 Combustible Gas Leak Detector, please refer to the following common problems and solutions:
| Problem | Possible Solution |
|---|---|
| Device does not power on | Check if the 9V battery is correctly installed and has sufficient charge. Replace with a new battery if necessary. |
| Inaccurate or inconsistent readings | Ensure the device has completed its warm-up cycle (approx. 40 seconds). Perform an auto-zero in a clean, gas-free environment. Check the sensor for any visible contamination or damage; consider replacing the sensor if issues persist. |
| Audible or vibration alarm not working | Verify that the alarm functions are not disabled (if applicable to your model). Check for any physical obstructions to the beeper. |
| Probe is stiff or damaged | Handle the flexible probe with care. If the probe or sensor is damaged, it may need to be replaced. |
For more comprehensive troubleshooting steps or issues not listed here, please consult the official user manual PDF: GD-3308 User Manual (PDF).
8. Warranty and Support
For information regarding the product warranty, technical support, or service, please contact the seller or the manufacturer directly. Details may also be available in the full user manual PDF.
Please retain your proof of purchase for any warranty claims.