FNIRSI FNIRSI-GC-02
FNIRSI Geiger Counter Nuclear Radiation Detector User Manual
Model: FNIRSI-GC-02
Brand: FNIRSI
Introduction
The FNIRSI-GC-02 Geiger Counter is a portable nuclear radiation detector designed for precise measurement of Gamma (γ), X-ray, and Beta (β) radiation. Featuring an IPS display, rechargeable battery, and multiple dosage units, this device provides real-time monitoring and cumulative dose tracking for various environments. Its compact design and user-friendly interface make it an essential tool for personal safety, industrial applications, and environmental monitoring.

Image: Front view of the FNIRSI-GC-02 Geiger Counter, showing its IPS display and control buttons.
Setup Guide
1. Unboxing and Initial Inspection
Carefully remove the Geiger Counter from its packaging. Inspect the device for any visible damage. Ensure all accessories, including the charging cable and hanging rope, are present.

Image: Contents of the FNIRSI-GC-02 package, including the device, hanging rope, charging cable, and instruction manual.
2. Charging the Device
The FNIRSI-GC-02 is equipped with a built-in 850mAh rechargeable lithium battery. For optimal performance, fully charge the device before first use.
- Connect the provided USB charging cable to the device's charging port.
- Connect the other end of the USB cable to a standard USB power adapter (not included) or a computer's USB port.
- The battery indicator on the IPS display will show charging status. A full charge typically takes up to 6 hours.
- Disconnect the charger once the battery is full to prolong battery life.

Image: Close-up of the FNIRSI-GC-02 showing the USB-C charging port and the charging process.
Operating Instructions
1. Power On/Off
- To power on, press and hold the OK/Power button (center button with power symbol) until the display illuminates.
- To power off, press and hold the OK/Power button until the display turns off.
2. Understanding the Display
The IPS display provides real-time radiation readings and various operational parameters.

Image: The FNIRSI-GC-02 display showing real-time cumulative value, current alarm value, and cumulative alarm value, along with icons for X-ray and Y-ray detection.
- Real-time Cumulative Value: Displays the current radiation dose rate (e.g., uSv/h).
- Current Alarm Value: Shows the set threshold for immediate radiation alerts.
- Cumulative Alarm Value: Shows the set threshold for total accumulated radiation alerts.
- Battery Indicator: Displays the current battery level.
- Time: Shows the elapsed monitoring time.
3. Navigating Menus and Settings
Use the navigation buttons (Up, Down, Left, Right, OK, Settings) to adjust device parameters.
- Press the Settings button (gear icon) to enter the settings menu.
- Use the Up and Down buttons to navigate through menu options.
- Press OK to select an option or confirm a setting.
- Press the Left button (back arrow) to return to the previous menu or the main screen.
4. Setting Alarm Thresholds
The device supports audible and visual alarms when radiation levels exceed preset limits.

Image: The FNIRSI-GC-02 displaying an alarm state with a flashing red light and audible alert icon, indicating radiation levels have exceeded the set limit.
- Enter the Settings menu.
- Navigate to Alarm Settings.
- Adjust the Current Alarm Value (dose rate) and Cumulative Alarm Value (total dose) using the Up and Down buttons.
- Confirm settings with the OK button.
5. Monitoring Modes
The device offers multiple monitoring interfaces for detailed analysis.

Image: The FNIRSI-GC-02 displaying various monitoring interfaces, including a real-time graph of radiation levels over time, and different data views.
- From the main screen, use the Left/Right buttons to switch between different display modes, such as real-time numerical display, historical graph, and cumulative data views.
6. Auto Sleep Function
To conserve battery, the device features an auto-sleep function.

Image: The FNIRSI-GC-02 settings menu showing the auto-sleep option, with adjustable sleep times from 5 to 60 minutes.
- In the Settings menu, navigate to Sleep Settings.
- Enable or disable the sleep function and set the desired inactivity time before the device enters sleep mode.
Maintenance
1. Cleaning
To maintain the device's performance and appearance:
- Wipe the exterior with a soft, dry cloth.
- Do not use abrasive cleaners, solvents, or strong chemicals, as these may damage the casing or display.
- Ensure no liquids enter the device's ports or openings.
2. Battery Care
The built-in lithium polymer battery requires proper care for longevity:
- Recharge the device when the battery indicator shows low power.
- Avoid completely draining the battery frequently.
- If storing the device for an extended period, charge it to approximately 50% and recharge every few months to prevent deep discharge.
- Use only the provided charging cable or a compatible high-quality USB cable.
3. Storage
Store the Geiger Counter in a cool, dry place, away from direct sunlight, extreme temperatures, and high humidity. Keep it away from strong magnetic fields and corrosive substances.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Device does not power on. | Battery is depleted. | Charge the device for at least 30 minutes. |
| Device does not power on. | Power button not held long enough. | Press and hold the OK/Power button for 3-5 seconds. |
| Inaccurate readings. | Interference from other electronic devices. | Move away from strong electromagnetic fields. |
| Inaccurate readings. | Device not calibrated (unlikely for user). | Contact customer support if issues persist after basic troubleshooting. |
| Alarm not sounding. | Alarm volume is off or too low. | Check alarm settings in the menu and adjust volume. |
| Alarm not sounding. | Radiation level below alarm threshold. | Verify the alarm threshold settings. |
| Screen frozen or unresponsive. | Temporary software glitch. | Perform a soft reset by holding the power button until the device restarts, or let the battery drain and recharge. |
Specifications

Image: Detailed diagram showing the dimensions of the FNIRSI-GC-02 and a table of its technical specifications.
| Feature | Detail |
|---|---|
| Model Number | FNIRSI-GC-02 |
| Product Dimensions | 106.5 x 44.5 x 25 mm (4.1 x 1.8 x 1 inches) |
| Weight | 4.66 ounces |
| Detection Radiation Type | Ionizing radiation (γ-rays, X-rays, β-rays) |
| Detector | Energy compensation GM tube (Geiger counter tube) |
| Dose Current Rate | 0.00-100000 μSv/h (10 mSv/h) |
| Cumulative Dose Equivalent | 0.00 μSv-500.0 mSv |
| Energy Range | 48 KeV-1.5 Me V ≤±30% (for 137Cs) |
| Sensitivity | 80 CPM/μSv (for Co-60) |
| Dosage Units | μSv/h, μGy/h, mR/h, CPS, CPM |
| Battery Type | 1 Lithium Polymer battery (included) |
| Battery Capacity | 850 mAh |
| Alarm Method | Light, Sound |
| Supported Languages | Chinese, English, Russian, German, Japanese, Portuguese, Spanish, Korean |
Usage Scenarios

Image: Visual representation of various environments where the FNIRSI-GC-02 can be used, including daily living, industrial, medical, and personal protection scenarios.
- Daily Living Environment: Detection of radiation from suspected sources like imported products, jewelry, and building materials.
- Industrial Environment: Monitoring in nuclear waste sites, radiation source transportation, mining plants, steel recycling, and metallurgy.
- Medical Environment: Use in radiology, CT, CR, DR, blood irradiation equipment, and with radioactive nuclides or iodine drugs.
- Personal Protection: Occupational health, customs, medical staff, pregnant women, and general personal safety.
Warranty and Support
FNIRSI products are manufactured to high quality standards. For specific warranty information, please refer to the warranty card included with your product or visit the official FNIRSI website. If you encounter any issues or require technical assistance, please contact FNIRSI customer support through their official channels.
For the latest support information and FAQs, please visit the FNIRSI Store on Amazon.
Related Documents - FNIRSI-GC-02
![]() |
FNIRSI GC-02 Radiation Detector and Dosimeter User Manual This user manual provides a comprehensive guide to the FNIRSI GC-02 radiation detector and dosimeter, covering its features, specifications, operation, settings, and maintenance. Learn how to use this device for accurate detection of ionizing radiation. |
![]() |
FNIRSI GC-02 Nuclear Radiation Detector User Manual User manual for the FNIRSI GC-02 nuclear radiation detector, detailing its features, operation, and specifications for accurate radiation measurement. |
![]() |
FNIRSI GC-02 Nuclear Radiation Detector User Manual This manual provides detailed information on the FNIRSI GC-02 nuclear radiation detector, including its features, specifications, operation, and maintenance. |
![]() |
FNIRSI GC-03 Radiation and Electromagnetic Field Detector User Manual User manual for the FNIRSI GC-03, a multifunctional detector for radiation, electric field, and magnetic field. Covers product overview, features, operation, settings, troubleshooting, and specifications. |
![]() |
FNIRSI GC-01 Nuclear Radiation Detector User Manual User manual for the FNIRSI GC-01 Nuclear Radiation Detector, covering product description, key features, parameters, operation, unit conversion, notes, maintenance, and production information. |
![]() |
FNIRSI GC-01 Nuclear Radiation Detector User Manual User manual for the FNIRSI GC-01 Nuclear Radiation Detector, covering product description, key features, parameters, operation, maintenance, and conversion of radioactive units. |





