H2S sensor GS301

NH3electrochemicalfor indoor air quality

Overview
The Milesight GS301 Bathroom Odor Detector measures ammonia (NH3) and hydrogen sulfide (H2S) concentrations along with temperature and humidity in real time. Designed for wireless, battery-powered deployment, it supports LoRaWAN® and Milesight D2D for local and cloud-based monitoring and control, and provides on-site audible/visual alarm indicators.

Key selling points

• 4-in-1 sensing: NH3, H2S, temperature and humidity with electrochemical and environmental sensors
• Local alarm: built-in buzzer and traffic-light LED for immediate on-site indication
• Dual connectivity: simultaneous LoRaWAN® and Milesight D2D for low-latency direct control and remote integration
• Replaceable batteries: 4 × 4000 mAh ER18505 Li-SOCl2 for multi-year operation under typical reporting intervals

Sensing & alarms

• Gas thresholds: configurable alarms when NH3 or H2S exceed set limits; device issues local alarm and uplinks alarm packets
• Designed for integration with ventilation/HVAC systems to trigger automated exhaust or fan control
• Measurement ranges and resolutions suitable for indoor restroom air quality monitoring

Connectivity & management

• LoRaWAN®: OTAA/ABP Class A, multi-region frequency support (CN470 / IN865 / RU864 / EU868 / US915 / AU915 / KR920 / AS923-1/2/3/4)
• Milesight D2D: direct device-to-device communication for <1s response in control scenarios
• NFC configuration: set parameters and templates via Milesight ToolBox mobile app without wired connection
• Cloud integration: compatible with Milesight IoT Cloud for visualization, alerts, reports and fleet management

Typical applications

• Smart restrooms and public toilet air-quality monitoring
• HVAC-driven ventilation control in restroom facilities
• Odor and hygiene management in commercial buildings, malls, airports, stations and service areas

Configuration & installation

• NFC setup: install Milesight ToolBox → enable NFC on phone → attach to device → verify credentials and apply configuration
• Mounting: wall screw mounting; compact enclosure with protective coating for humid restroom environments

Characteristics / technical specifications

• Model: GS301
• Brand: Milesight
• Detected gases: Ammonia (NH3) and Hydrogen Sulfide (H2S) — electrochemical sensors
• NH3 range: 0 ~ 10 ppm; resolution: 0.01 ppm; accuracy: ±5% FS (-40 ~ 35 °C); long-term drift <1%/month
• H2S range: 0 ~ 5 ppm; resolution: 0.001 ppm; accuracy: ±5% FS (-40 ~ 35 °C); long-term drift <1%/month
• Temperature: -40 ~ 85 °C; accuracy ±0.2 °C; resolution 0.1 °C
• Humidity: 0 ~ 100% RH; accuracy ±2% RH; resolution 0.5% RH
• Wireless: LoRaWAN® (OTAA/ABP Class A); antenna: internal; Tx power: 16 dBm (868 MHz) / 19 dBm (470 MHz) / 22 dBm (915 MHz); sensitivity: -137 dBm
• Milesight D2D supported alongside LoRaWAN® for ultra-low latency control
• Indicators: 1 × status/alarm LED (traffic-light) + 1 × built-in buzzer
• Button: 1 × external Reset/Reboot
• Power: 4 × 4000 mAh ER18505 Li-SOCl2 replaceable batteries (typical battery life ≈ 3 years at 10 min reporting, 25 °C)
• Sensor life: > 3 years
• Operating conditions: -40 °C ~ 55 °C; 0% ~ 95% RH (non-condensing)
• Ingress protection: IP30
• Housing: PC+ABS (flame retardant), white
• Weight: 221.4 g (batteries included)
• Dimensions: 120 × 85 × 32.5 mm
• Installation: wall screw mounting
• Approvals / Compliance: CE, FCC; Safety EN62368-1; RoHS