Meter capable of measuring ambient dust concentration

摘要

A dust meter includes a duct member having a lower portion formed with an air inlet, and an upper portion formed with an air outlet, and confining an air passage. A heating element is used to heat air in the air passage to result in air flow from the air inlet to the air outlet. A light emitter is operable so as to generate a light beam in the air passage. An optical sensor module includes a light sensor responsive to changes in optical flux in the air passage attributed to dust content of the air that flows from the air inlet to the air outlet. The sensor module generates an electrical signal that varies with the optical flux detected by the light sensor. A processing circuit determines an actual ambient dust concentration by referring the electrical signal from the sensor module to pre-established data in the processing circuit.