Gas sensors are employed in a wide range of applications in the fields of safety, health, instrumentation etc… Common examples are domestic/commercial alarms for explosive or toxic gases or in automotive application, as gas… Electronics Projects, Gas Detector Circuit ATtiny45 “avr project, microcontroller projects, “
Gas sensors are employed in a wide range of applications in the fields of safety, health, instrumentation etc… Common examples are domestic/commercial alarms for explosive or toxic gases or in automotive application, as gas leakage detectors for LPG powered cars and exhausts detectors inside any fuel-powered truck/car. Such sensors, nowadays, are found also in applications involving air quality control systems and pollution monitoring.
Today’s sensors, while featuring an high sensitivity to a wide gases variety, are very compact in size and have significantly reduced their power consumption to better adapt to portable solutions.
Building a system with a gas sensor is not as easy as it could appear. Despite the sensor could be treated basically as a variable resistor (which value depends on gas concentration in air) the practical implementation in a project should be done considering some design rules, especially if the final circuit is a device to be used in a field where reliability is strongly required (e.g. safety). As an example the internal elements of a sensor (heater and gas sensitive resistors) have to be constantly kept under control to avoid failures leading to a wrong alarm indication; furthermore, if the application needs to achieve a good measurement accuracy, factors like environment temperature, sensor life etc… have to be taken into account.
All those features and controls require to introduce in the project a certain amount of external circuitry (including components like comparators, temperature sensor, spare logic etc…) to carry out functions such us temperature compensation, sensor heating control, sensor warm-up time, sensor life time check and so on…
Read more: GAS DETECTOR CIRCUIT Gas Detector Circuit ATtiny45 project files: gas-detector-circuit-attiny45.rar alternative link2 alternative link3