Autonomous programmable detector designed for the detection of toxic gases and O2 with electrochemical technology and CO2 with infrared technology. Three programmable alarm relay outputs with different levels for each gas. Digital control over the state of the sensor. Automatic hardware status testing. Digital filter based on variable sampling of the averages of the sensor values. Automatic thermal compensation that provides a correct response to temperature variations. Exact automatic zero adjustment. Monitors zero relative to sensor and electronics response. STANDGAS automatically performs a test every 30 minutes: if the drift -drift- is greater or less than 2% of the total scale value, it will be reset to zero; otherwise the data will be displayed as a reading. Other functions only accessible at the factory allow knowing the remaining useful life of the sensor, the date of manufacture and the last calibration, in addition to the serial number.