MP135 / MP503 Air Quality & Gas Sensor

The MP135 / MP503 Gas Sensor is a compact metal-oxide semiconductor gas-sensing component designed for air-quality monitoring and gas detection applications. It offers good sensitivity to methane and other target gases, making it suitable for gas-monitoring experiments, environmental sensing, and DIY electronic projects.

The sensor is manufactured using multilayer thick-film technology. It features a miniature Al₂O₃ ceramic substrate with a built-in heater and metal-oxide semiconductor sensing material. The sensing element is protected inside a metal housing, providing a compact and durable structure suitable for long-term applications.

The sensor’s electrical conductivity changes according to the concentration of the target gas. As the gas concentration increases, the conductivity of the sensing material also changes. An external measurement circuit can detect this change and convert it into an electrical output corresponding to the gas concentration.

With its fast response and recovery, good stability, low power consumption, strong anti-interference capability, and simple drive circuit, the MP135 / MP503 is suitable for air-quality monitoring systems, gas detection experiments, Arduino projects, and other embedded sensing applications.

Features

• Designed for air-quality and gas detection
• Good sensitivity to methane
• Wide gas concentration detection range
• Strong anti-interference capability
• Low power consumption
• Fast response and recovery
• Good long-term stability
• Long service life
• Low-cost sensing solution
• Simple drive circuit
• Metal-oxide semiconductor sensing element
• Miniature Al₂O₃ ceramic substrate
• Integrated heater
• Suitable for DIY gas-sensing projects
• Useful for environmental monitoring applications
• Suitable for microcontroller-based projects

Specifications

Parameter	Specification
Product Type	Air Quality / Gas Sensor
Sensor Type	Metal-Oxide Semiconductor
Model	MP135 / MP503
Primary Application	Air Quality and Gas Detection
Gas Sensitivity	Good sensitivity to methane
Sensing Element	Metal-Oxide Semiconductor
Substrate	Al₂O₃ Ceramic
Heater	Integrated Heater
Response	Fast
Recovery	Fast
Stability	Good
Drive Circuit	Simple External Circuit
Application	Gas Detection / Air Quality Monitoring

Design and Construction

The MP135 / MP503 uses a metal-oxide semiconductor sensing layer deposited on a miniature alumina (Al₂O₃) ceramic substrate. A heater element is integrated into the sensing structure to maintain the required operating conditions for gas detection.

The sensing element and heater are connected through electrode leads and enclosed within a metal housing and cap. This construction provides a compact sensing solution suitable for integration into gas-detection equipment and electronic prototypes.

The sensor’s resistance or conductivity changes when exposed to the target gas. This electrical variation can then be measured using an appropriate external circuit.

Working Principle

The sensor operates by detecting changes in the electrical conductivity of its metal-oxide semiconductor sensing material.

When the sensor is exposed to the target gas, the gas interacts with the sensing material and changes its electrical conductivity. Generally, as the concentration of the target gas increases, the sensor’s conductivity changes accordingly.

An external circuit can measure this change in resistance or conductivity and convert it into an electrical signal that can be processed by a microcontroller or other electronic system.

A suitable calibration process is required to relate the sensor’s electrical output to an actual gas concentration.

Gas Detection

The MP135 / MP503 is designed for air-quality and gas-sensing applications, with stated good sensitivity to methane.

The actual sensor response depends on factors such as:

• Gas type
• Gas concentration
• Temperature
• Humidity
• Heater operating conditions
• Sensor aging
• Circuit configuration
• Calibration

For accurate gas-concentration measurement, the sensor should be properly calibrated for the specific application.

Drive Circuit

The sensor can be operated using a relatively simple external circuit. The change in sensing-element conductivity can be converted into a measurable voltage or other electrical signal using a suitable resistor, voltage-divider circuit, amplifier, ADC, or microcontroller input.

The exact circuit should be designed according to the required gas-detection range and measurement accuracy.

Applications

• Air-quality monitoring
• Methane detection experiments
• Gas leakage detection
• Environmental sensing
• Indoor air monitoring
• Gas concentration monitoring
• Arduino gas sensor projects
• Microcontroller-based sensing
• DIY air-quality systems
• IoT environmental monitoring
• Industrial gas monitoring prototypes
• Safety monitoring experiments
• Educational electronics projects
• Embedded gas-detection systems
• Sensor research and development

Advantages

• Good methane sensitivity
• Wide concentration range
• Fast response and recovery
• Good stability
• Low power consumption
• Long service life
• Simple operating circuit
• Compact sensing element
• Low-cost solution
• Suitable for embedded systems
• Easy to integrate into prototype circuits

Package Includes

• 1 × MP135 / MP503 Air Quality / Gas Sensor

Product Disclaimer

Product images are for illustrative and representational purposes only. The actual sensor may vary slightly in colour, metal housing, dimensions, markings, terminal configuration, or overall appearance depending on the manufacturing batch.

The sensor’s electrical response is affected by gas concentration, temperature, humidity, heater conditions, circuit design, and sensor aging. It should not be treated as a precision gas-concentration instrument without appropriate calibration.

The sensor requires a suitable heater supply and measurement circuit for proper operation. Do not connect the sensing element directly to a microcontroller without an appropriate interface circuit.

The exact gases detected, sensitivity, concentration range, and electrical characteristics should be verified against the datasheet of the specific sensor version supplied.