本传感器采用非色散红外（NDIR）原理，利用单通道技术对空气中二氧化碳浓度进行实时测量。具有精度高、稳定性好、寿命长等特点，广泛应用于室内空气质量监测、暖通空调、温室大棚、智能家居等领域。
This sensor uses Non-Dispersive Infrared (NDIR) principle with single-channel technology to measure CO₂ concentration in real time. It features high accuracy, good stability, and long lifespan, and is widely used in indoor air quality monitoring, HVAC, greenhouses, smart homes, etc.
| 参数 / Parameter | 说明 / Description |
|---|---|
| 工作原理 / Principle | 非色散红外（NDIR） / Non-Dispersive Infrared (NDIR) |
| 通道 / Channel | 单通道 / Single channel |
| 工作温度 / Operating Temp. | 0℃ ~ 50℃ |
| 工作湿度 / Operating Humidity | 0 ~ 90% RH（非冷凝 / non-condensing） |
| 测量范围 / Measuring Range | 常规 / Standard: 400~2000ppm 扩展 / Extended: 可达 / up to 10000ppm |
| 测量精度 / Accuracy | ±40ppm ±3% 读数 / of reading |
| 重复性 / Repeatability | >97% |
| 响应速度 / Response Time | ≤120 秒 / seconds |
| 测量间隔 / Measurement Interval | 4 秒 / seconds |
| 工作电压 / Operating Voltage | 4.5 ~ 5.5V DC |
| 功耗 / Power Consumption | 平均 / Average: 30mA 峰值 / Peak: 300mA |
| 通信方式 / Communication | UART，Modbus协议 / UART with Modbus protocol |
传感器内部红外光源发出的红外光经过气室被CO₂分子吸收，剩余光强由红外探测器接收。通过单通道检测特定波长（4.26μm）的吸收衰减，结合内部算法计算出CO₂浓度值，不受其他气体干扰。
The infrared light emitted by the internal source passes through the gas chamber and is absorbed by CO₂ molecules. The remaining light intensity is detected by an infrared detector. Using a single channel at a specific wavelength (4.26μm), the sensor calculates CO₂ concentration via internal algorithms, without interference from other gases.
硬件接口：UART (TTL电平)
波特率：9600 (默认)
数据位：8，停止位：1，校验位：无
Modbus RTU 读取CO₂浓度示例（功能码0x03）
从机地址：0x01，寄存器起始地址：0x0000 (CO₂高16位)，数量0x0002
请求帧：01 03 00 00 00 02 C4 0B
响应帧：01 03 04 00 01 02 10 3A 7F
→ CO₂ = 0x00010210 = 6928 ppm
Hardware Interface: UART (TTL level)
Baud rate: 9600 (default)
Data bits: 8, Stop bits: 1, Parity: None
Modbus RTU Read CO₂ Example (Function code 0x03)
Slave address: 0x01, Register start: 0x0000 (CO₂ high 16 bits), Quantity: 0x0002
Request: 01 03 00 00 00 02 C4 0B
Response: 01 03 04 00 01 02 10 3A 7F
→ CO₂ = 0x00010210 = 6928 ppm
| 引脚 / Pin | 定义 / Definition | 说明 / Description |
|---|---|---|
| VCC | 电源正 / Power+ | 4.5~5.5V |
| GND | 电源负 / Power- | 接地 / Ground |
| TXD | 串口发送 / UART TX | 接外部RX / Connect to external RX |
| RXD | 串口接收 / UART RX | 接外部TX / Connect to external TX |
※ TXD/RXD 为 3.3V/5V 兼容 TTL 电平 / TTL 3.3V/5V tolerant.