4-in-1 NH3 H2S CH4 CO2 Industrial Air Gas Sensor RS485 Protocol – GAOTek
4-in-1 industrial gas sensor for NH3, H2S, CH4, and CO2 detection with RS485 Modbus RTU output, high accuracy, and IP65 waterproof design.
Description
Description
Product Parameters
| Measure name | Measure range | Measure accuracy | Measure resolution |
| NH3 | 0~100 ppm | ±3% | 0.1 ppm |
| H2S | 0~10 ppm | ±3% | 0.01 ppm |
| CH4 | 0~100% LEL | ±3% | 0.1% LEL |
| CO2 | 0~6000 ppm | ±3% | 1 ppm |
| Technical Parameter | Specification |
| Response time | ≤ 15 s |
| Load resistance | 100 Ω |
| Repeatability | ≤ 1% FS |
| Stability (per year) | ≤ 2% FS |
| Working temperature | -20 ~ 60 ℃, @5 ~ 95% RH |
| Storage temperature | -25 ~ 80 ℃ |
| Power supply voltage | DC 10 ~ 24 V, recommended: DC 12 V |
| Maximum power consumption | 100 mA @ 12 V |
| Communication interface | RS485 |
| Communication protocol | MODBUS RTU |
| Communication rate | Software setting: 2400, 4800, 9600, 19200, 38400, 115200 bps, etc. Default: 9600 bps |
| Data format | Default 8N1 (1 start bit, 8 data bits, 1 stop bit, no parity) |
| Communication method | The transmitter operates as a MODBUS RTU slave station. The master station (touch screen, PLC, upper computer, etc.) uses master-slave polling to query the transmitter’s real-time data. |
| Node address | 1 ~ 255 |
| Number of nodes | Theoretically up to 128 transmitters on the same bus; in actual applications, up to 1/2 ~ 2/3 |
| Transmission distance | 1000 meters (RS485 dedicated communication cable) |
| Protection treatment | The transmitter is treated with “three preventions” before leaving the factory to ensure long-term use in high-temperature and high-humidity soil environments. |
| Installation method | Wall-mounted |