1. Introduction
The AEGTEST AGT-2309 is a portable carbon monoxide (CO) detector designed for continuous monitoring of CO levels in the air. Equipped with a high-precision sensor, it provides rapid detection and alerts to help ensure your safety in various environments. This manual provides essential information on how to set up, operate, maintain, and troubleshoot your device.

Image 1.1: The AEGTEST AGT-2309 Portable CO Detector highlighting its features such as 0-1000ppm detection, 15-day standby, high-accuracy sensor, audible & visual alerts, Type-C charging, and compact design.
2. Safety Information
Carbon monoxide (CO) is a colorless, odorless, and tasteless toxic gas that can be fatal. It is often referred to as the "invisible killer" because it is undetectable by human senses. This device is designed to detect CO and alert you to its presence, but it is not a substitute for proper ventilation and maintenance of fuel-burning appliances.
2.1 About Carbon Monoxide
Carbon monoxide (CO) is produced when fuels such as gasoline, wood, propane, charcoal, or other fossil fuels are burned incompletely. Common sources include furnaces, gas stoves, water heaters, fireplaces, and vehicle exhaust.

Image 2.1: Visual representation of carbon monoxide (CO), emphasizing its invisible nature.
2.2 Dangers of Carbon Monoxide Exposure
Inhaling high concentrations of CO can lead to serious health risks and even death. Symptoms of CO poisoning can be subtle and often mistaken for other illnesses. Common symptoms include:
- Headache
- Nausea and vomiting
- Dizziness
- Fatigue and weakness
- Shortness of breath
- Confusion
- Loss of consciousness

Image 2.2: Common dangers and symptoms associated with carbon monoxide exposure.
2.3 Potential Sources of Carbon Monoxide
Be aware of potential CO sources in your environment. While the detector provides protection, understanding these sources is crucial for prevention:
- Fireplaces
- Gas stoves and ovens
- Water heaters
- Barbecue grills (never use indoors)
- Portable heaters
- Vehicle exhaust (e.g., running engines in garages)

Image 2.3: Examples of common household and outdoor items that can produce carbon monoxide.
3. Product Overview
The AGT-2309 is a compact and lightweight device designed for portability and ease of use. It features a clear display, simple controls, and a durable build.
3.1 Components
The package includes:
- AGT-2309 Carbon Monoxide Detector
- Type-C Charging Cable
- Lanyard
- User Manual

Image 3.1: Front view of the AGT-2309 detector, showing the display and control buttons.

Image 3.2: Side view of the AGT-2309 detector, highlighting the Type-C charging port.

Image 3.3: Back view of the AGT-2309 detector, showing the integrated stand for desktop use.
3.2 High-Precision Sensor
The AGT-2309 incorporates a UK-made DDS sensor, providing high accuracy and a rapid response time of 0.3 seconds to detect CO levels from 0 to 1000 PPM.

Image 3.4: Internal view of the AGT-2309, highlighting the DDS sensor for precise CO detection.
4. Setup
4.1 Charging the Device
Before first use, fully charge the AGT-2309. Connect the provided Type-C cable to the charging port on the side of the device and plug the other end into a standard USB power adapter (not included).
- A full charge provides over 15 days (360 hours) of continuous standby time.
- The battery indicator on the display will show charging status.

Image 4.1: The AGT-2309 connected for Type-C charging, illustrating its extended standby time.
4.2 Initial Power On
Press and hold the power button (U) for a few seconds until the display illuminates. The device will perform a self-test and then enter standby mode, indicated by a green breathing light.
5. Operating Instructions
5.1 Power On/Off
- To Power On: Press and hold the power button (U) until the screen turns on.
- To Power Off: Press and hold the power button (U) until the screen turns off.
5.2 Understanding the Display
The device's display shows real-time CO concentration in Parts Per Million (PPM), battery status, and alarm indicators.
- CO Level: Displays the current CO concentration from 0 to 1000 PPM.
- Battery Indicator: Shows the remaining battery life.
- Alarm Icon: Appears when CO levels exceed the set threshold.

Image 5.1: The AGT-2309 display, indicating CO levels and customizable alarm thresholds (e.g., 24, 50, 100, 200, 500 PPM).
5.3 Alarm Thresholds and Alerts
The AGT-2309 provides both visual and audible alerts when CO levels reach or exceed the preset alarm threshold. The alarm threshold can be customized using the device's buttons.
- Visual Alert: The breathing light turns red, and a flame icon appears on the display.
- Audible Alert: An alarm sounds to notify you of the elevated CO levels.
- Standby Mode: A green breathing light flashes to indicate normal operation.

Image 5.2: The AGT-2309 demonstrating its visual (red light) and audible alarm features.
5.4 Placement and Usage
The portable design of the AGT-2309 allows for flexible placement. Use the integrated stand for tabletop placement or the included lanyard for hanging. For optimal detection, place the device in areas where CO may accumulate, such as near fuel-burning appliances or in sleeping areas.

Image 5.3: The AGT-2309 utilizing its stand for desktop use and the lanyard for portable hanging.
The AGT-2309 is suitable for various environments:
- Home
- Camping
- Travel (hotels, RVs)
- Vehicles (trucks, cars)

Image 5.4: Wide application scenarios for the AGT-2309, including home, camping, truck, and hotel environments.

Image 5.5: The AGT-2309 provides protection in diverse locations such as camping, travel, home, and RVs.
6. Testing the Device
Regularly testing your AGT-2309 ensures it is functioning correctly and provides reliable protection. It is recommended to test the device periodically, especially before travel or extended use.
6.1 Recommended Test Methods
- Test with Cigarette Smoke: Briefly expose the detector to cigarette smoke. The device should react by displaying CO levels and potentially triggering an alarm if the concentration is high enough.
- Test with Paper Burning in Low-Oxygen Conditions: Carefully burn a small piece of paper in a confined, low-oxygen environment (e.g., inside a jar with limited air flow). Place the detector near the smoke. The device should detect the CO produced by incomplete combustion and activate its alerts.
Caution: Perform these tests in a well-ventilated area and with extreme care to avoid fire hazards or excessive CO exposure. Do not intentionally expose yourself to high CO levels.

Image 6.1: Visual guide for testing the AGT-2309 using cigarette smoke or controlled paper burning.
7. Maintenance
7.1 Cleaning
To maintain optimal performance, keep the device clean. Wipe the exterior with a soft, dry cloth. Do not use abrasive cleaners, solvents, or immerse the device in water.
7.2 Battery Care
The AGT-2309 uses a rechargeable Lithium-Ion battery. To prolong battery life:
- Charge the device fully before long periods of inactivity.
- Avoid extreme temperatures, which can degrade battery performance.
- Recharge when the low battery indicator appears.
8. Troubleshooting
If you encounter issues with your AGT-2309, refer to the table below for common problems and solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Low battery or no charge. | Charge the device using the provided Type-C cable. |
| Alarm sounds frequently without apparent CO source. | High sensitivity setting or presence of other gases/vapors. | Ensure proper ventilation. If false alarms persist, consider adjusting the alarm threshold (refer to operating instructions). |
| Display is dim or unreadable. | Low battery or environmental conditions. | Charge the device. Ensure the device is not exposed to extreme temperatures. |
| Device does not respond to buttons. | Temporary software glitch. | Try restarting the device by holding the power button. If unresponsive, allow the battery to fully drain and then recharge. |
9. Specifications
Technical specifications for the AEGTEST AGT-2309 Portable Carbon Monoxide Detector:
| Feature | Detail |
|---|---|
| Model Number | AGT-2309 |
| Detection Range | 0-1000 PPM (Parts Per Million) |
| Response Time | 0.3 seconds |
| Sensor Type | DDS Sensor (UK-made) |
| Battery Type | 1 Lithium Ion battery (included) |
| Standby Time | Up to 15 days (360 hours) |
| Charging Port | Type-C |
| Alerts | Audible and Visual (Red light, Flame icon) |
| Item Weight | 5.6 ounces (0.16 Kilograms) |
| Package Dimensions | 5.67 x 4.33 x 1.65 inches |
10. Warranty and Support
The AGT-2309 has undergone rigorous quality inspection and factory calibration. For specific warranty details, please refer to the documentation included with your purchase or contact AEGTEST customer support.
If you have any questions, require technical assistance, or need to report an issue, please contact AEGTEST customer support through the retailer where the product was purchased or visit the official AEGTEST website for contact information.





