The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

The invention relates to detecting a composition of a sample or contamination in liquids by detecting corresponding changes in their thermal properties. In a disclosed arrangement, an apparatus is provided comprising a first probe element configured to provide a first surface in direct contact with the sample and a second surface that is not in direct contact with the sample. A measurement system measures a rate of heat transfer through the first surface. A processing unit analyses the measured rate of heat transfer in order to detect a heat transfer characteristic of the sample that is indicative of a composition of the sample.

A gas measurement device measures gas using a gas sensor including a sense resistance exposed to the gas and a reference resistance not exposed to the gas. The gas measurement device applies a first current value and a second current value to the sensor. A detector functions to detect a first resistance variation and a second resistance variation of the sense resistance exposed to the gas with respect to the reference resistance as a function of the first current value and the second current value, respectively. The resistance variation dependent on relative humidity is then determined as a function of the first and second resistance variations and a first constant. The resistance variation dependent on gas content is then determined as a function of the first and second resistance variations and a second (different) constant.

A gas measurement device measures gas using a gas sensor including a sense resistance exposed to the gas and a reference resistance not exposed to the gas. The gas measurement device applies a first current value and a second current value to the sensor. A detector functions to detect a first resistance variation and a second resistance variation of the sense resistance exposed to the gas with respect to the reference resistance as a function of the first current value and the second current value, respectively. The resistance variation dependent on relative humidity is then determined as a function of the first and second resistance variations and a first constant. The resistance variation dependent on gas content is then determined as a function of the first and second resistance variations and a second (different) constant.

One example discloses a ratiometric device, including: a current source having a first current, a second current different from the first current, and a current-select program; a sensor device responsive to a gas and having a sensor-cold temperature T(cold,sens) in response to the first current and a sensor-hot temperature T(hot,sens) in response to the second current; a reference device having a reference-cold temperature T(cold,ref) in response to the first current and a reference-hot temperature T(hot,ref) in response to the second current; and wherein the ratiometric device includes a temperature difference ratio output based on T(cold,sens), T(hot,sens), T(cold,ref) and T(hot,ref).

One example discloses a ratiometric device, including: a current source having a first current, a second current different from the first current, and a current-select program; a sensor device responsive to a gas and having a sensor-cold temperature T(cold,sens) in response to the first current and a sensor-hot temperature T(hot,sens) in response to the second current; a reference device having a reference-cold temperature T(cold,ref) in response to the first current and a reference-hot temperature T(hot,ref) in response to the second current; and wherein the ratiometric device includes a temperature difference ratio output based on T(cold,sens), T(hot,sens), T(cold,ref) and T(hot,ref).

We disclose herein an environmental sensor system comprising an environmental sensor comprising a first heater and a second heater in which the first heater is configured to consume a lower power compared to the second heater. The system also comprises a controller coupled with the environmental sensor. The controller is configured to detect if a measured value of a targeted environmental parameter is present. The controller is configured to switch on at least one of the first and second heaters based on the presence and/or result of the measured value of the targeted environmental parameter.

We disclose herein an environmental sensor system comprising an environmental sensor comprising a first heater and a second heater in which the first heater is configured to consume a lower power compared to the second heater. The system also comprises a controller coupled with the environmental sensor. The controller is configured to detect if a measured value of a targeted environmental parameter is present. The controller is configured to switch on at least one of the first and second heaters based on the presence and/or result of the measured value of the targeted environmental parameter.

A gas detector includes a gas detection element having a protection layer formed of an oxide film mainly containing tantalum oxide (Ta.sub.2O.sub.5). Since the protection layer has excellent condensed-water resistance, even when water droplets adhere thereto, the morphology thereof does not change from dense to porous. Thus, since a change in property of the protection layer, which would otherwise be caused by adhesion of water droplets, can be reduced in the gas detector, even when water droplets adhere to the outermost surface layer of the gas detection element, impurities can be prevented from entering the protection layer (the outermost surface layer), whereby a change in thermal capacity of the gas detection element can be reduced. Thus, the gas detection element of the gas detector has excellent alkali resistance and condensed-water resistance.

A gas detector includes a gas detection element having a protection layer formed of an oxide film mainly containing tantalum oxide (Ta.sub.2O.sub.5). Since the protection layer has excellent condensed-water resistance, even when water droplets adhere thereto, the morphology thereof does not change from dense to porous. Thus, since a change in property of the protection layer, which would otherwise be caused by adhesion of water droplets, can be reduced in the gas detector, even when water droplets adhere to the outermost surface layer of the gas detection element, impurities can be prevented from entering the protection layer (the outermost surface layer), whereby a change in thermal capacity of the gas detection element can be reduced. Thus, the gas detection element of the gas detector has excellent alkali resistance and condensed-water resistance.