CEM GD-3308 Combustible Gas Leak Detector User Manual

1. Safety Information

1.1. Safety Symbols

In this operator's manual and on the product, safety symbols and signal words are used to communicate important safety information. This section is provided to improve understanding of these signal words and symbols.

This is the safety alert symbol. It is used to alert you to potential personal injury hazards. Obey all safety messages that follow this symbol to avoid possible injury or death.

⚠️ DANGER

Indicates a hazardous situation which, if not avoided, will result in death or serious injury.

⚠️ WARNING

Indicates a hazardous situation which, if not avoided, could result in death or serious injury.

⚠️ CAUTION

Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.

ⓘ NOTICE

Indicates information that relates to the protection of property.

This symbol means read the operator's manual carefully before using the equipment. The operator's manual contains important information on the safe and proper operation of the equipment.

1.2. General Safety Rules

⚠️ Warning

Read all safety warnings and instructions. Failure to follow the warnings and instructions may result in electric shock, fire and/or serious injury.

1.2.1. Work Area Safety

• Keep your work area clean and well lit. Cluttered or dark areas invite accidents.
• Do not operate equipment in explosive atmospheres, such as in the presence of flammable liquids, gases or dust. Equipment can create sparks which may ignite the dust or fumes.
• Keep children and by-standers away while operating equipment. Distractions can cause you to lose control.

1.2.2. Electrical Safety

• Avoid body contact with earthed or grounded surfaces such as pipes, radiators, ranges and refrigerators. There is an increased risk of electrical shock if your body is earthed or grounded.
• Do not expose equipment to rain or wet conditions. Water entering equipment will increase the risk of electrical shock.

1.2.3. Personal Safety

• Stay alert, watch what you are doing and use common sense when operating equipment. Do not use equipment while you are tired or under the influence of drugs, alcohol or medication. A moment of inattention while operating equipment may result in serious personal injury.
• Use personal protective equipment. Always wear eye protection. Protective equipment such as dust mask, non-skid safety shoes, hard hat or hearing protection used for appropriate conditions will reduce personal injuries.
• Do not overreach. Keep proper footing and balance at all times. This enables better control of the power tool in unexpected situations.

1.2.4. Equipment Use and Care

• Do not force equipment. Use the correct equipment for your application. The correct equipment will do the job better and safer at the rate for which it is designed.
• Do not use equipment if the switch does not turn it ON and OFF. Any tool that cannot be controlled with the switch is dangerous and must be repaired.
• Disconnect the batteries from the equipment before making any adjustments, changing accessories or storing. Such preventive safety measures reduce the risk of injury.
• Store idle equipment out of the reach of children and do not allow persons unfamiliar with the equipment or these instructions to operate the equipment. Equipment can be dangerous in the hands of untrained users.
• Maintain equipment. Check for misalignment or binding of moving parts, missing parts, breakage of parts and any other condition that may affect the equipment's operation. If damaged, have the equipment repaired before use. Many accidents are caused by poorly maintained equipment.
• Use the equipment and accessories in accordance with these instructions, taking into account the working conditions and the work to be performed. Use of the equipment for operations different from those intended could result in a hazardous situation.
• Use only accessories that are recommended by the manufacturer for your equipment. Accessories that may be suitable for one piece of equipment may become hazardous when used with other equipment.
• Keep handles dry and clean; free from oil and grease. Allows for better control of the equipment.

1.2.5. Service

Have your equipment serviced by a qualified repair person using only identical replacement parts. This will ensure that the safety of the tool is maintained.

1.3. Specific Safety Information

⚠️ Warning

This section contains important safety information that is specific to this tool. Read these precautions carefully before using the CEM Combustible Gas Leak Detector to reduce the risk of fire, explosion or other serious personal injury.

! SAVE THESE INSTRUCTIONS!

Keep this manual with the tool for use by the operator.

1.3.1. Combustible Gas Detector Safety

• High concentrations of combustible gases can cause explosions, fires, asphyxia and other hazards that could cause serious personal injury or death. Know the characteristics of the gas you are working with and use proper precautions to avoid hazardous conditions.
• Always turn on and calibrate the gas detector in an area known to be free of combustible gases. Calibration in an area containing combustible gas will result in incorrect calibration and lower than actual readings. This could result in combustible gases not being detected.

2. Product Overview

2.1. Description

The CEM GD-3308 Combustible Gas Leak Detector is a gas leak locating tool designed to identify the presence and isolate the source of combustible gases such as methane, propane, butane, ammonia, carbon monoxide, hydrogen, and many others. It can detect even low levels of combustible gas in seconds.

The detector uses an internal heated sensor that interacts with gases to indicate their presence. It provides visual, audio, and vibration feedback mechanisms. The device can detect gas concentrations between 1-1000ppm or 0-10000ppm by setting high and low concentration detection. The LCD display, audible alerts, and vibration alerts inform the user about gas presence.

The GD-3308 comes equipped with an attached flexible 16-inch probe hose for precise detection.

2.2. Features

• Digital LCD Display
• Visible, audible and vibration alarm for noisy & bright environments (GD-3306 only has visible/audible/vibration alarm, GD-3308 has LCD)
• Highly sensitive and reliable
• Pinpoint small Leaks: Detects all combustible gas leaks even tiny leaks
• Auto Zero function
• Highly Accuracy, quick response
• 16-inch flexible probe with replaceable sensor
• Auto power off
• TRI Mode Detection

2.3. Controls & Display

The device features an intuitive layout for easy operation and clear feedback.

The device features:

• LCD Display: Shows gas concentration, explosion limitation, and other indicators.
• Auto Zero Enable/Disable: Button to quickly adjust the sensor's zero point.
• High/Low Sensitivity: Buttons to switch between sensitivity levels.
• Auto Power Off Enable/Disable: Controls the automatic shutdown feature.
• BackLight Enable/Disable: Controls the display backlight.
• Audible Alert Enable/Disable: Controls the sound alarm.
• Vibration Alert Enable/Disable: Controls the vibration alarm.
• ON/OFF Button: Powers the device on and off.

2.4. Standard Equipment

• CEM Combustible Gas Leak Detector (GD-3308)
• 5V/1A Adapter
• Replaceable Gas Sensor
• Operator's Manual (this document)

2.5. Measurable Gases

The GD-3308 can detect a wide range of combustible gases, including:

• Methane (Natural Gas)
• Hydrogen
• Carbon Monoxide
• Propane
• Ethylene
• Ethane
• Hexane
• Benzene
• Iso-Butane
• Ethanol
• Acetaldehyde
• Formaldehyde
• Toluene
• P-Xylene
• Ammonia
• Hydrogen Sulfide

Natural Gas typically consists of a high percentage of methane and smaller percentages of propane and other gases.

3. Setup and Operation

3.1. Changing/Installing Batteries

⚠️ Warning

In case of unnecessary danger, it is not allowed to charge or replace batteries in the concentration of combustible gas. Set up and Operate the gas detector according to these procedures to reduce the risk of fire, explosions and serious injury and incorrect measurements.

The CEM Combustible Gas Leak Detector has a built-in battery, without the need to replace it. If the battery is low, use a 5V/1A adapter to charge. Please remove the battery in case of battery leakage before long-term storage or transportation. In the concentration of combustible gas, it is not allowed to replace the batteries or use the adapter, in order to reduce the risk of explosion, fire or other serious injury. It is not allowed to operate when charging.

3.2. Pre-Operation Inspection

⚠️ Warning

Before each use, inspect your CEM Combustible Gas Leak Detector and correct any problems to reduce the risk of injury or incorrect measurements.

1. Clean any oil, grease or dirt from equipment. This aids inspection.
2. Inspect the CEM Combustible Gas Leak Detector for any broken, worn, missing, misaligned or binding parts, or any other condition which may prevent safe and normal operation.
3. Check that the warning labels are present, firmly attached and readable.
4. If any issues are found during the inspection, do not use the CEM Combustible Gas Leak Detector until it has been properly serviced.
5. Following the Set-Up and Operation instructions, turn ON and calibrate the gas detector. Once calibration is complete use a combustible gas source (such as an unlit lighter), to confirm that the gas detector senses the gas. If the gas detector does not sense the gas, do not use the unit until it has been properly serviced. Remove the gas source and allow several minutes for the sensor to stabilize prior to use.

3.3. Set-Up and Operation

⚠️ Warning

High concentrations of combustible gases can cause explosions, fires, asphyxia and other hazards that could cause serious personal injury or death. Know the characteristics of the gas you are working with and use proper precautions to avoid hazardous conditions.

Always turn on and calibrate the gas detector in an area known to be free of combustible gases. Calibration in an area containing combustible gas will result in incorrect calibration and lower than actual readings. This could result in combustible gases not being detected.

Set up and Operate the gas detector according to these procedures to reduce the risk of fire, explosions and serious injury and incorrect measurements.

1. Check for an appropriate work area as indicated in the General Safety Section.
2. Determine the application and confirm that you have the correct equipment. See the Specifications section for information on sensitivity, gases detected and other information.
3. Make sure that all equipment has been properly inspected.
4. In an area where combustible gases are known to not be present, turn on the gas detector by pressing and releasing the ON/OFF button for one second. The gas detector will vibrate, beep. The gas detector then starts an approximately 40 second sensor heat up and calibration. It will display a countdown. Once the countdown is over, it will beep and vibrate. And it will display the current gas concentration values, gas explosion limitation, and the max gas concentration values. If the battery shape is void, this indicates that the batteries need to be charged. If the LCD flashes and beeps, this indicates that the sensor has failed and that the unit needs to be serviced. If the gas detector is left ON for more than ten minutes with no activity and Auto Power Off is enabled, it will automatically shut OFF to conserve the batteries.
5. It will buzzer when you press the button, except it starts in 40s.
6. Press and release the Vibration Alert button to turn it ON and OFF. The gas detector will vibrate twice when turning the Vibration Alert ON and vibrate once when turning the Vibration Alert OFF. Press and release the BackLight button to turn it ON and OFF.
7. Enter the area to be monitored. Pay close attention to the gas level indicators (see Table 1). As gas levels increase, LCD display values will rise and the frequency of the Audible Alert beeping and the Vibration Alert vibration will increase. See Table 1 for information on methane concentration levels and gas detector feedback.
8. In the low sensitivity setting, the lowest concentration of methane detected is 10ppm. Switch the sensitivity to the high setting by pressing the high sensitivity button (H). The lowest concentration of methane detected is 100ppm. Sensitivity can be changed at any time by pressing the High Sensitivity (H) or Low Sensitivity (L) buttons. If locating a leak, use the gas detector to find areas of lower gas concentration and follow back to the source. In a piping system, trace the system, stopping at the joints to monitor the gas levels.
9. When gas detection is complete, turn the CEM Combustible Gas Leak Detector OFF by pressing the ON/OFF button.

3.4. BackLight

Press and release the BackLight button to enable or disable. When BackLight is enabled, BackLight is open, otherwise it is closed.

3.5. Auto Zero

Press and release the Auto Zero button to enable or disable. Enabling Auto Zero can quickly adjust the zero point of the sensor, improve sensitivity, and reduce the interference of unknown gases.

3.6. Auto Power Off

Press and release the Auto Power Off button to enable or disable. If the gas detector is left ON for more than ten minutes with no activity and Auto Power Off is enabled, it will automatically shut OFF to conserve the batteries.

4. Maintenance

4.1. Cleaning

Do not immerse the CEM Combustible Gas Leak Detector in water. Wipe off dirt with a damp soft cloth. Do not use aggressive cleaning agents or solutions. Treat the instrument as you would a telescope or camera.

4.2. Sensor Calibration/Replacement

The CEM Combustible Gas Leak Detector requires no calibration other than that done at regular startup. If the sensor should fail, the sensor can be replaced.

4.2.1. Calibration Procedure

1. In the complete preheating into the measurement condition, press the vibration button and the buzzer button. The equipment will produce a beep after successful operation (hereafter, always keep the buttons pressed).
2. Press the BackLight keys 4 times, then press the APO button 4 times. The equipment will produce a beep successfully after the operation. The LCD screen numerical concentration of combustible gas indicator area will not show, indicating entry into calibration mode. To enter the school table mode, you need to cancel the AutoZero mode.
3. Press the APO button to select the calibration gas concentration. The calibration has a total of three points: 400ppm, 0ppm, 5000ppm. Cycle through these points by short pressing the APO key. Select and confirm the gas concentration calibration. Do not press other buttons. Wait 3 seconds, the equipment beeps, and the LCD screen displays the calibration icon (CAL) to indicate calibration mode.
4. During manual calibration, the LCD screen displays the calibration icon (CAL). The concentration of combustible gas and numerical LCD screen indication area will still not indicate the combustible gas concentration value. The maximum concentration of combustible gas, the combustible gas explosion limit value indication area will indicate the original measurement data. For example, if the maximum value indicates a display area of 2, and the explosion limit indicator area displays 18, the original measurement data of 218 concentration and environmental concentration should be calibrated consistently. If calibrating to 0ppm, ensure the equipment is placed in a 0ppm environment. The original measurement data should be stable. After a long press of the ON/OFF button, the calibration value can be saved and written to the data. A short press of the ON/OFF button cancels the calibration.
5. To cancel the calibration or if there is a calibration data error (e.g., calibration of 1000ppm data results in a value less than 0ppm), the calibration will exit. The LCD screen icon (CAL) will flash for 10 seconds and beep. If calibration is successful, it will exit calibration, and the concentration of combustible gas and numerical LCD screen instructions will display the combustible gas concentration calibration value.
6. Before the LCD screen displays the calibration icon (CAL), while pressing the vibration button and the buzzer button, releasing either button will exit the calibration mode without saving any calibration results.

4.2.2. Restore Factory Settings

1. In the complete preheating into the measurement condition, press the High/Low Sensitivity button and the buzzer button. The successful operation of equipment will produce a beep after (then must always keep the High/Low Sensitivity button and buzzer button are pressed).
2. Press the button 4 times for continuous vibration, then press the Autozero button 4 times. The equipment will produce a beep successfully after the operation. The LCD screen will show 'RESET', indicating entry into the production setting mode.
3. Before 'RESET' disappears from the LCD screen, if both the High/Low Sensitivity button and the buzzer button were pressed, releasing either button at any time will exit the restore factory settings mode, leading to an inability to restore factory settings.

5. Troubleshooting

6. Specifications

Gas Concentration levels may differ depending on the specific gas detected.

6.1. Gas Detector Feedback For Methane Concentration Levels

7. Storage & Disposal

7.1. Storage

The CEM Combustible Gas Leak Detector must be stored in a dry, secure area between -10°C (14°F) and 60°C (158°F).

Store the tool in a locked area out of the reach of children and people unfamiliar with the CEM Combustible Gas Leak Detector.

Remove the batteries before any long period of storage or shipping to avoid battery leakage.

7.2. Disposal

Parts of the CEM Combustible Gas Leak Detector contain valuable materials and can be recycled. There are companies that specialize in recycling that may be found locally. Dispose of the components in compliance with all applicable regulations. Contact your local waste management authority for more information.

8. User Tips

• Battery Care: Ensure the device is fully charged before use. If storing for an extended period, remove the battery to prevent leakage.
• Calibration Environment: Always calibrate the detector in an area known to be free of combustible gases to ensure accurate readings.
• Hydrogen Detection: This detector is capable of detecting hydrogen gas, among other combustible gases.

9. Warranty and Support

For warranty information, technical support, or service inquiries, please refer to the contact information provided with your purchase or visit the official CEM website. Keep your purchase receipt as proof of purchase.

10. Certifications

The CEM GD-3308 Gas Leak Detector complies with various international standards and holds the following certifications:

• ISO 9001:2015
• ISO 13485
• CE certification
• UL certification
• ETL certification
• GS certification
• FDA certification
• FCC certification
• ATEX certification
• RoHS certification
• REACH certification
• PAHS certification
• IP certification

11. About CEM

Learn more about CEM's commitment to precision measurement and innovation: