Capacitive humidity sensor Adafruit Industries 393 digital temperature sensor with long transmission distance and stability

Product Overview

The AM2302 (also known as DHT22) is a digital relative humidity and temperature sensor featuring a capacitive humidity sensing element and an internal thermistor. It offers a calibrated digital signal output via a 1-wire bus, making it easy to integrate with microcontrollers. This sensor is designed for full-range temperature compensation, outstanding long-term stability, and requires no extra components. Its small size, low power consumption, and long transmission distance (up to 100 meters) make it suitable for a wide range of harsh application environments. The AM2302 is fully interchangeable and available in a standard or big case with wires.

Product Attributes

• Sensor Type: Digital relative humidity and temperature sensor
• Sensing Element: Capacitive type, Polymer humidity capacitor
• Signal Output: Calibrated digital signal via 1-wire bus
• Packaging: 4 pins, fully interchangeable
• Available Variants: Standard case, Big case with wires
• Wire Colors: Red (Power Supply), Black (GND), Yellow (Data Output)

Technical Specifications

Application Scenarios

The AM2302 is well-suited for various applications requiring accurate humidity and temperature monitoring, including:

• Harsh application occasions
• Environments where long transmission distances are required
• Applications demanding high precision and long-term stability
• Integration into systems where extra components are not desired

Important Attentions

• Avoid operating or storing the sensor outside the specified RH range to prevent accelerated aging.
• Chemical vapors can interfere with sensor performance; follow specific recovery steps if contamination occurs.
• Temperature significantly affects relative humidity; maintain a stable temperature environment and position the sensor away from heat sources.
• Prolonged exposure to strong light and UV may degrade performance.
• Use high-quality shielded wires for optimal communication quality and distance.
• Welding temperature should be below 260C.
• Avoid using the sensor under dew conditions.
• Do not use this product in safety-critical devices or applications where failure could cause personal injury.
• The sensor requires a 1-second delay after power-up before receiving instructions.
• A 100nF capacitor can be added between VDD and GND for wave filtering.
• The AM2302's 1-wire bus is proprietary and not compatible with Maxim/Dallas 1-wire bus.

Capacitive humidity sensor Adafruit Industries 393 digital temperature sensor with long transmission distance and stability Images