Abstract: A device for sensing a gas comprises a plastics housing (106, 107) moulded in situ around at least one portion of a conducting lead frame (100), the housing defining an enclosure (113) and being provided with means for enabling gas flow into the enclosure. A gas sensitive element (114) within the enclosure (113) is mounted to the conducting lead frame (100). The conducting lead frame (100) comprises connection leads which are accessible through, and at least partially encapsulated by, the wall of the housing.

Abstract: A gas sensor assembly comprising a gas-sensitive element, and a first pulse modulation circuit comprising a first switching device is disclosed. The gas-sensitive element and the first switching device are arranged in series with a power supply. The first pulse modulation circuit further comprises a first control module adapted to control the first switching device in accordance with a monitored parameter of the gas-sensitive element, the parameter varying with the temperature of the element, thereby controlling the power consumed from the power supply by the gas-sensitive element.