• Flexible sensing pad design for easy installation and compatibility with pipes of different diameters.
• Suitable for various pipelines and flat-wall containers.
• Built-in 2A relay for direct load control, with RS485 communication available.
• Supports DC 5V/12V/24V power input, with selectable NO/NC output modes.

Product Features

1. Non-Contact Liquid Detection

The PPK-Y-28 sensor is designed for non-metallic pipes (outer diameter ≥ 11mm) and flat-wall containers. It detects liquid levels without direct contact with the liquid, preventing corrosion caused by strong acids, strong alkalis, or other corrosive liquids. It is also unaffected by scale buildup or impurities, enabling reliable detection of liquid presence from outside the container or pipe.

2. Intelligent Calibration & Level Memory Function

Features automatic liquid level calibration and memory functions. The sensor supports clear liquid level status indication and allows multi-point series connection for flexible system integration.

3. High Accuracy & Stable Detection

Provides accurate and stable detection performance and is capable of detecting high-temperature liquids, including boiling water levels.

4. Solid-State Electronic Design

Adopts a fully electronic circuit design without mechanical moving parts, ensuring:

• High reliability
• Long service life
• Stable performance

5. High Sensitivity & Strong Anti-Interference Capability

Designed with high sensitivity and excellent interference resistance. Special circuit processing technology effectively reduces:

• Power frequency interference
• Common-mode interference
• External electromagnetic interference

Compatible with standard DC 5V, 12V, and 24V power supplies commonly used in industrial and electronic applications.

6. Wide Material Compatibility

The sensor can detect liquid levels through various non-metallic materials, including:

• Plastic
• Glass
• Ceramic
• Other non-metallic containers

It supports container wall thicknesses up to 20mm and can be installed on various shapes of containers, including:

• Curved surfaces
• Arc-shaped surfaces
• Cylindrical pipes and tanks

7. Flexible Voltage Options

Available in DC 5V / 12V / 24V versions, making it suitable for integration into various electronic devices, control systems, and industrial applications.

---

Working Principle

The intelligent non-contact capacitive liquid level sensor uses the dielectric change caused by liquid presence to detect liquid levels.

When no liquid is near the sensor, the sensor maintains a certain static capacitance due to distributed capacitance between the sensor and ground.

As the liquid level gradually rises and approaches the sensing area, the liquid generates an additional parasitic capacitance that couples with the existing static capacitance, causing the total capacitance value to increase.

The changing capacitance signal is then processed by the internal control IC, which converts the capacitance variation into an electrical signal. Through a specific detection algorithm, the sensor analyzes the magnitude of the change.

When the capacitance variation exceeds the preset threshold, the system determines that the liquid level has reached the detection point and outputs the corresponding signal.