7-in-1 Air Quality Sensor Product Manual

I. Product Overview

Function Description:

Detect temperature, humidity, carbon dioxide, formaldehyde TVOC, PM2.5, PM10, The detection data is output through the bus protocol to the central control device for control or display on the screen.

Selection suggestion:

is widely applicable to users with air detection needs such as households, kitchens and bathrooms, office buildings, hotels, hospitals, schools, stations, museums, exhibition centers, factories, agriculture, etc. It is also suitable for indoor air detection institutions, air purifiers, and fresh air system practitioners, Geek, Environmental players, environmental testing professionals, and other professionals use it.

1.2 Product Features

Product Features

• Simultaneously output temperature, humidity C02, Seven sets of data including formaldehyde, TVOC, PM2.5, and PM10.
• The PM2.5 sensor adopts the principle of laser scattering. The air scatters the laser by measuring the suspended particles in the air through the measurement chamber. The scattered laser light is collected at a specific angle to obtain the curve of the scattered light intensity over time. The microprocessor calculates the equivalent particle size of the particles and the number of particles of different sizes per unit volume based on the Mie theory, achieving accurate measurement.
  Unique laser self calibration technology ensures accuracy.
  
• Adopting dual frequency data acquisition technology, the current particle concentration can be detected in real time.
  
• The range of particle diameter detection is from 0.3um to 10um.
  
• PM2.5 is based on TSI8530 as the standard, which is consistent with the testing equipment of most metrology bureaus
  
• CO2 adopts infrared non dispersive principle, single pass NDIR method, and has 24-hour self calibration function
  
• Formaldehyde TVOC all use electrochemical principles, with high sensitivity and the ability to recognize even at low concentrations.
  
• Temperature adopts NTC principle, humidity adopts HIH principle, with a wide measurement range and high accuracy
  
• Three dimensional air duct design improves air flow rate and accurately identifies particle content.
  
• The sensor adopts a metal shielding shell with good anti-interference performance.

2, Technical parameters

2.1 Detection index parameters

2.2 Communication Parameters

3, Installation and wiring

3.1 Mechanical Installation

• Installation Location1.5-2 meters above the ground, avoiding ventilation blind spots
• Installation spacingIt is recommended to install one sensor every 50 square meters
• Direction requirementsThe sensor air inlet should avoid obstructions

3.2 Electrical Connections

4, Detailed Explanation of Communication Protocol

4.1 Protocol Framework

Adopting standard Modbus RTU protocol, data frame structure:

Private protocol

1. Modify device address

1. Operation process

1. Power on the device: The device automatically provides feedback on the current address (5 bytes, such as1A 21 07 01 01).
2. Send modification instruction:

• Format: （1A 21 07 01 01） + 固定码（F8 E7 D6） + 1A 21 07 01 02
• Example:
  Change address1A 21 07 01 01to1A 21 07 01 02:
  发送指令：1A 21 07 01 01 F8 E7 D6 1A 21 07 01 02

2. Key note

• Check code: F8 E7 D6is a fixed code for modifying addresses.

II. Querying Device Data

1. Sending Query Instructions

• Format: 设备地址（XX XX XX XX XX） + 固定指令（86 86 86 0F）
• Example:
  Querying device data with address1A 21 07 01 01:

  发送指令：1A 21 07 01 01 86 86 86 0F  

2. Data feedback parsing

• Feedback format:

  设备地址（XX XX XX XX XX） + 参数组（每2字节为一组） + 结束符（0F）  

• Example Analysis:
  Feedback Data:

  XX XX XX XX XX 00 01 01 00 02 01 00 03 01 00 04 01 00 05 01 00 06 01 02 BC 01 0F  

Analysis results:

• Formaldehyde:00 01→ 1 μ g/m ³
• TVOC:00 02→ 2 μ g/m ³
• PM2.5:00 03→ 3 μ g/m ³
• Temperature:00 04→ 4 ℃ (01indicates positive sign)
• Humidity:00 05→ 5%
• PM10: 00 06→ 6 μg/m³
• carbon dioxide:02 BC → 0x02BC= 700 ppm

3. Numerical conversion method

• Convert hexadecimal to decimal:
  for example02 BC→ Convert to decimal:

  0x02BC = (2 × 256) + (188 × 1) = 700  

5, Data interpretation standards

5.1 Air quality level

5.2 Health Guidelines

• red alert(Any parameter exceeds the standard):
• Immediately activate the fresh air system
• Suggestions for personnel evacuation
• Search for sources of pollution
• Orange Alert(Two parameters approaching the limit):
• Suggest increasing ventilation
• Sensitive individuals should pay attention to protection

6, Maintenance and Calibration

6.1 Daily Maintenance

6.2 Automatic Calibration Mechanism

• CO ₂ sensor: Automatic zero calibration every 24 hours
• Temperature and humidity sensor: Power on automatic calibration
• Particle sensorDynamic baseline calibration technique

7, Troubleshooting

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