Explosive gas warning semiconductor sensor for detection of esp. methane

摘要

The sensor includes an element (2) located in a aluminium housing (1) where the entry (7) for external air is via a gas-permeable filter (8). At least one of the multiple filter layers is of activated charcoal. An electronic evaluation circuit also provided monitors the electrical resistance (5) of the sensor. The sensor resistance over a period since startup is stored in non-volatile memory. A caution and warning alarm at different concentration levels is raised after a pre-determined internal as the sensor measurement value exceeds these thresholds.