The Liquefied Petroleum Gas LPG gas leak detector is an instrument designed to measure the concentration of combustible LPG. Its core function involves using a gas sensor to detect LPG components (propane/butane) and converting concentration changes into electrical signals via physical or chemical reactions. Once the signal is processed and reaches a specific threshold, the device triggers an audible and visual alarm and initiates linked actions, such as shutting off the gas supply.
1.Core Operational Workflow
Signal Processing: Weak electrical signals from the sensor undergo amplification, filtering, and temperature compensation to ensure stability and reliability.
Microprocessor Analysis: The core microcontroller continuously reads the processed signals and converts them into specific gas concentration values.
Threshold Assessment and Alarming: Low-concentration warning: When the concentration reaches a preset level (e.g., 25% LEL), the detector issues a continuous audible and visual alarm, indicating a potential slow leak and prompting the user to inspect the system.
High-concentration emergency alarm: When the concentration reaches a dangerous threshold (e.g., above 50% LEL), the detector immediately issues a continuous, urgent audible and visual alarm; immediate action is required in this situation.
Linked Actions: When the concentration meets or exceeds the preset alarm value, the device immediately activates the audible and visual alarm and can output signals to trigger linked equipment, such as solenoid valves or exhaust fans.
2.Key Detection Technologies
Catalytic Combustion: The most common principle. Combustible gas undergoes flameless combustion on the surface of a catalytic element, generating heat that alters the resistance of an electrical bridge circuit; suitable for industrial and commercial use, though sensors require protection against poisoning.
Semiconductor: Gas adsorption causes a significant change in the resistivity of the semiconductor material; low cost and high sensitivity make it common for household use, though it is susceptible to interference from temperature and humidity.
Infrared Spectroscopy: Uses the specific infrared absorption characteristics of LPG for non-contact measurement; offers strong interference resistance, long service life, and maintenance-free operation (no calibration required), though costs are generally higher.
Thermal Conductivity: Detection based on differences in gas thermal conductivity; primarily used for high concentrations or specific industrial applications.
3.Key Features
Detection Targets: Primarily targets hydrocarbons such as propane and butane; due to the low Lower Explosive Limit (LEL) of LPG (approximately 1.5%–9.5%), high-sensitivity detection is required.
Output Signals: Standard outputs include 4–20 mA current, relay contacts, or digital bus interfaces (e.g., M-BUS), supporting remote monitoring and automated control.
Safety Mechanisms: Features automatic zero-point calibration, sensor poisoning resistance, and explosion-proof certification (e.g., Ex d IIC T6) to ensure stable operation in hazardous environments.