A54-23 4-in-1 Air Quality Sensor

MAXMAC A54-23 is a compact 4-in-1 air quality sensor for HVAC systems, fresh-air units and AHU equipment. It integrates PM2.5, CO2, temperature and humidity sensing to support ventilation control and indoor comfort management.

Featuring laser scattering PM2.5 detection, NDIR CO2 sensing, CMOSens temperature and humidity measurement and RS485 communication, A54-23 helps HVAC equipment obtain stable multi-parameter air quality data.

Integrated PM2.5, CO2, temperature and humidity monitoring
CO2 measuring range: 400-9999 ppm, resolution 1 ppm
PM2.5 measuring range: 0-999 µg/m³, resolution 1 µg/m³
Temperature and humidity data for indoor comfort-condition control
RS485 communication for HVAC, AHU and BMS system integration

Sensor Technology Principle

All-in-One Sensor Principle Diagram

Technical Specifications

A54-23 4-in-1 Air Quality Sensor

Product Name

A54-23 4-in-1 Air Quality Sensor

Model

A5423

Functions

PM2.5 + CO2 + Temperature + Humidity

Communication

RS485

Dimensions

66.4 × 51.4 × 19 mm

Housing Material

PC+ABS, V0 flame-retardant

Operating Voltage

DC12-DC24V

Operating Current

Average: 35 ± 5 mA @ 12.0 VDC; Peak: <150 mA (10 ms), at room temperature

Standby Power Consumption

≤ 1 W

Power Consumption

≤ 3 W

PM2.5 Sensing Principle

Laser scattering technology

PM2.5 Measuring Range

0-999 µg/m³

PM2.5 Resolution

1 µg/m³

PM2.5 Accuracy

≤100 µg/m³: ±15 µg/m³; >100 µg/m³: ±15%

CO2 Sensing Principle

NDIR infrared technology

CO2 Measuring Range

400-9999 ppm

CO2 Resolution

1 ppm

CO2 Accuracy

±(50 ppm + 5% of reading)

Temperature Sensing Principle

CMOSens®

Temperature Measuring Range

-20°C to 85°C

Temperature Resolution

0.1°C

Temperature Accuracy

Humidity Sensing Principle

CMOSens®

Humidity Measuring Range

1-99%RH

Humidity Resolution

0.1%RH

Humidity Accuracy

±5%RH

Interface

4-pin socket

Communication Interface

RS485 protocol, 4-pin (+ / A+ / B- / GND)

Physical Connector

GH1.25-4P locking connector

Operating Environment

-10°C to 50°C, 0-95%RH, non-condensing

Storage Environment

-20°C to 65°C, 0-99%RH, non-condensing

The matching GH1.25-4P locking terminal cable should be prepared by the user for connection.

Applicable Systems

HVAC Systems
Fresh Air Systems
Air Handling Units (AHUs)
Ventilation Control Systems
Smart Building Air Quality Monitoring
Commercial Indoor Comfort Monitoring
Demand-Controlled Ventilation
Public Building Air Quality Management

Application Areas

Residential and central air conditioning indoor air quality monitoring

Residential / Central Air Conditioning

Designed for residential and central air conditioning systems, this A54 configuration provides indoor air quality data to help HVAC, ventilation and purification systems respond more accurately to changing room conditions.

Fresh air and ventilation system monitoring

Ventilation Systems

Suitable for residential and commercial ventilation systems, the sensor provides stable data for airflow regulation, air exchange and indoor air quality management in long-running systems.