| Model | GD400-H2S | 
| Sampling Method | Pump suction & diffusion dual-use type | 
| Gas Type | Hydrogen Sulfide (H2S) | 
| Principle | Electrochemistry | 
| Measuring Range | 0 to 50ppm, 0 to 100ppm, 0 to 200ppm | 
| Resolution | 0.01ppm (0-50ppm), 0.1ppm (0-100/200ppm) | 
| Response Time | ≤30 seconds | 
| Precision | ≤±2%F.S except for special gases | 
| Language | Chinese/English (More language can be customized) | 
| Automatically Test and Calibrate after Power-on | Including reset, maximum value (MAX), minimum value (MIN), STEL, TWA value | 
| Unit | ppm and mg/m3 can be switched and displayed by one key, and the concentration value is automatically converted by the system | 
| Display | Monochrome graphics (160 x 96), the screen can be automatically flipped | 
| Backlight | The backlight time can be manually set, and will be turned on automatically when an alarm is issued. | 
| Data Record | Can store 100,000 sets of data, the storage interval is adjustable from 5 to 3600 seconds, data can be exported, with a data cable | 
| Alarm | 95dB buzzer (@30cm), vibration alarm and flashing red LED and alarm status indication on the screen, alarm latched; diagnostic alarm and battery undervoltage alarm, pump block alarm; man down alarm, with early warning and optional real-time remote Bluetooth notification function
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| Battery | 3.7V rechargeable lithium battery, battery capacity 2200mA | 
| Working Hours | More than 15 hours in continuous pumping mode | 
| Charger | Travel charger with DC interface, charging time ≥ 4 hours | 
| Explosion-proof Grade | Ⅱ 2G Ex ia Ⅱ CT4 Ga | 
| Certification (EU regulations) | CE, ATEX (Standard: EN IEC 60079-0:2018, EN 60079-1:2014) | 
| Protection grade | IP67 | 
| Working Temperature | -20℃~+50℃ | 
| Humidity | 0~90%RH (no condensation) | 
| Environmental Pressure | 86~106Kpa | 
| Size | 157*84.5*59.5mm (including the back clip/water trap filter) (length * width * height) | 
| Weight | 365g (including battery, belt clip and filter) | 
| Extension Probe | About 480mm (Total Length), About 300mm (Probe Head) | 
| Package Included | 1 piece Gas detector, 1 piece 12V/1A DC power adapter, 1 piece USB cable, 1 piece User manual, 1 piece Warranty card, 1 piece Filter, 1 piece Aluminum suitcase |