Product Description
The M1001Y electrochemical formaldehyde module is a compact, general-purpose device designed to detect formaldehyde (CH2O) in the air using electrochemical principles. It features good selectivity and stability, with a built-in temperature sensor for compensation. The module offers both digital and analog voltage output modes, making it user-friendly. It combines mature electrochemical detection technology with sophisticated circuit design.

Module Features
- High sensitivity and resolution
- Low power consumption
- Long service life
- Provides UART data output
- High stability and excellent anti-interference ability
- Temperature compensation and excellent linear output

Main Applications
The module is suitable for use in portable meters, air quality monitoring equipment, air purifiers, fresh air ventilation systems, air conditioners, smart home equipment, and other similar applications.

Technical Index
- Detection Gas: Formaldehyde
- Interfering Gases: Alcohol, carbon monoxide, and others
- Output Data: UART output (3.3V level)
- Working Voltage: 3.7V to 5.5V
- Warm-up Time: ≤3 minutes
- Response Time: ≤60 seconds
- Recovery Time: ≤60 seconds
- Range: 0 to 5 ppm
- Resolution: ≤0.01 ppm
- Working Temperature: -20℃ to 50℃
- Working Humidity: 15%RH to 90%RH (no condensation)
- Storage Temperature: 0 to 25℃
- Service Life: 2 years (0℃ to 35℃ in air)
- Module Size: Length 23mm × Width 25.5mm × Height 6.5mm

Pin Definition
- Pin1: NC
- Pin2: NC
- Pin3: GND
- Pin4: Vin (voltage input 3.7V to 5.5V)
- Pin5: UART (RXD) 0 to 3.3V data input
- Pin6: UART (TXD) 0 to 3.3V data output
- Pin7: NC

Protocol
General Settings
- Baud Rate: 9600
- Data Bits: 8 bits
- Stop Bit: 1 bit
- Check Digit: None

Communication Commands
The module supports active upload and question-and-answer communication modes. By default, it actively uploads concentration values every second. To switch modes, specific command formats are used.

Checksum Calculation
The checksum is calculated by inverting the sum of bytes 1 to 7 and adding 1.

Cross Interference Characteristics
The sensor can respond to gases other than formaldehyde. Typical responses to common interference gases are provided in a table, indicating the equivalent formaldehyde concentration.

Precautions
- Complete soldering quickly to avoid sensor damage.
- Ensure an aging time of at least 48 hours before use.
- Avoid disassembling the sensor to prevent electrolyte leakage.
- Keep the sensor away from organic solvents, paints, and high-concentration gases.
- Do not encapsulate the sensor with resin materials or immerse it in an oxygen-free environment.
- Avoid long-term exposure to corrosive gases.
- Ensure a clean atmosphere when measuring the gas zero point.
- Avoid blocking or polluting the sensor's intake surface.
- Do not damage the waterproof and breathable membrane.
- Avoid excessive impact or vibration.
- Do not use the sensor if the shell is damaged or deformed.
- Store the working and counter electrodes in a short-circuit state.
- Avoid using hot melt adhesive or sealant with a curing temperature above 80℃.
- Do not store or use in high-concentration alkaline gas environments.