A54-25 Temperature and Humidity Sensor

MAXMAC A54-25 is a compact temperature and humidity sensor for HVAC systems, ventilation equipment and indoor environmental monitoring. It provides comfort-condition data for climate regulation, ventilation control and BMS integration.

Featuring CMOSens temperature and humidity measurement and RS485 communication, A54-25 supports stable equipment integration in residential HVAC, commercial ventilation and indoor environmental control systems.

Dedicated indoor temperature and humidity monitoring
Temperature measuring range: -20°C to 85°C, resolution 0.1°C
Humidity measuring range: 1-99%RH, resolution 0.1%RH
RS485 communication for HVAC and BMS system integration
Compact flame-retardant PC+ABS housing for long-term equipment integration

Sensor Technology Principle

All-in-One Sensor Principle Diagram

Technical Specifications

A54-25 Temperature and Humidity Sensor

Product Name

A54-25 Temperature and Humidity Sensor

Model

A5425

Functions

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

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 Environmental Monitoring
Commercial Indoor Comfort Monitoring
Industrial Environmental Control Systems
Public Building Environmental 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.