A method provides a diagnostic on a combined humidity and temperature sensing device including a humidity sensor having a humidity sensing element, a temperature sensor, and a heater. The method comprises obtaining a first temperature and a first relative humidity, heating the humidity sensing element with the heater, obtaining a second temperature and a second relative humidity after heating the humidity sensing element, and determining a difference between the first temperature and the second temperature and a difference between the first relative humidity and the second relative humidity. Diagnostic information representative of a possible malfunction of the humidity sensor is output when the difference between the first temperature and the second temperature is higher than a predetermined temperature difference threshold and the difference between the first relative humidity and the second relative humidity is lower than a predetermined humidity difference threshold.

A method provides a diagnostic on a combined humidity and temperature sensing device including a humidity sensor having a humidity sensing element, a temperature sensor, and a heater. The method comprises obtaining a first temperature and a first relative humidity, heating the humidity sensing element with the heater, obtaining a second temperature and a second relative humidity after heating the humidity sensing element, and determining a difference between the first temperature and the second temperature and a difference between the first relative humidity and the second relative humidity. Diagnostic information representative of a possible malfunction of the humidity sensor is output when the difference between the first temperature and the second temperature is higher than a predetermined temperature difference threshold and the difference between the first relative humidity and the second relative humidity is lower than a predetermined humidity difference threshold.

A temperature sensor and a relative humidity sensor are placed in an environment allowing air to flow and are displaced in an upstream-downstream direction of the airflow. An absolute humidity acquisition unit acquires absolute humidity of air from outputs from the temperature sensor and the relative humidity sensor. A delay adjustment unit delays an output from one of the temperature sensor and the relative humidity sensor placed upstream and to reconcile change-behaviors of outputs from the temperature sensor and the relative humidity sensor in response to a state change in air. The absolute humidity acquisition unit acquires the absolute humidity based on the output from the other of the temperature sensor and the relative humidity sensor placed downstream and an output acquired from the one sensor placed upstream and delayed in the delay adjustment unit.

It is an object of the present invention to provide a thermal humidity measuring device that has a configuration including a first heating element and a second heating element and that is capable of obtaining a plurality of measurement values (measured values) including humidity measured by the first heating element, by effectively utilizing each of the heating elements.

A thermal humidity measuring device 1 includes a first bridge circuit 2 that includes a first heating element 4 that senses humidity, and a second bridge circuit 3 that includes a second heating element 10 that heats air around the first heating element 4. In the thermal humidity measuring device 1, a first output signal Va5 is extracted from the first bridge circuit 2, and the humidity is sensed. A second output signal Va15 is extracted from the second bridge circuit 3, and the second output signal Va15 includes information relating to at least any one of pressure, an air flow rate, and air temperature.

The present invention obtains a humidity measuring device capable of performing self-diagnosis with high reliability. This humidity measuring device 20 has a diagnosis processing unit 25 for performing self-diagnosis by using gas temperatures and gas humidities before and after a gas in an ambient atmosphere to be measured is heat-controlled. The diagnosis processing unit has a diagnosis start determining unit 26 for determining whether the self-diagnosis can be started on the basis of an exchange state in the ambient atmosphere to be measured and the gas temperature and the gas humidity before the gas in the ambient atmosphere to be measured is heat-controlled, and a diagnosis continuation determining unit 28 for determining whether the self-diagnosis can be continued on the basis of the gas temperature and the gas humidity that are heat-controlled during the self-diagnosis.

The present invention obtains a humidity measuring device capable of performing self-diagnosis with high reliability. This humidity measuring device 20 has a diagnosis processing unit 25 for performing self-diagnosis by using gas temperatures and gas humidities before and after a gas in an ambient atmosphere to be measured is heat-controlled. The diagnosis processing unit has a diagnosis start determining unit 26 for determining whether the self-diagnosis can be started on the basis of an exchange state in the ambient atmosphere to be measured and the gas temperature and the gas humidity before the gas in the ambient atmosphere to be measured is heat-controlled, and a diagnosis continuation determining unit 28 for determining whether the self-diagnosis can be continued on the basis of the gas temperature and the gas humidity that are heat-controlled during the self-diagnosis.

A method for identifying a state of a stream of refrigerant includes capturing a plurality of sample images of a sensor for sensing the stream of the refrigerant, processing each of the plurality of sample images to identify a first color indicative of a dry refrigerant and a second color indicative of a wet refrigerant. The method also includes calculating an aggregated volume of each of the first color and the second color, wherein the aggregated volumes of the first color and the second color indicate a dry refrigerant or the wet refrigerant respectively in the stream. Further, the method includes comparing an aggregated volume ratio of the first color and the second color with a first threshold ratio and a second threshold ratio and determining the state as one of a dry state, a transient state, and a wet state based on the comparison.

A method for identifying a state of a stream of refrigerant includes capturing a plurality of sample images of a sensor for sensing the stream of the refrigerant, processing each of the plurality of sample images to identify a first color indicative of a dry refrigerant and a second color indicative of a wet refrigerant. The method also includes calculating an aggregated volume of each of the first color and the second color, wherein the aggregated volumes of the first color and the second color indicate a dry refrigerant or the wet refrigerant respectively in the stream. Further, the method includes comparing an aggregated volume ratio of the first color and the second color with a first threshold ratio and a second threshold ratio and determining the state as one of a dry state, a transient state, and a wet state based on the comparison.

A method provides a diagnostic on a combined humidity and temperature sensing device including a humidity sensor having a humidity sensing element, a temperature sensor, and a heater. The method comprises obtaining a first temperature and a first relative humidity, heating the humidity sensing element with the heater, obtaining a second temperature and a second relative humidity after heating the humidity sensing element, and determining a difference between the first temperature and the second temperature and a difference between the first relative humidity and the second relative humidity. Diagnostic information representative of a possible malfunction of the humidity sensor is output when the difference between the first temperature and the second temperature is higher than a predetermined temperature difference threshold and the difference between the first relative humidity and the second relative humidity is lower than a predetermined humidity difference threshold.

A method provides a diagnostic on a combined humidity and temperature sensing device including a humidity sensor having a humidity sensing element, a temperature sensor, and a heater. The method comprises obtaining a first temperature and a first relative humidity, heating the humidity sensing element with the heater, obtaining a second temperature and a second relative humidity after heating the humidity sensing element, and determining a difference between the first temperature and the second temperature and a difference between the first relative humidity and the second relative humidity. Diagnostic information representative of a possible malfunction of the humidity sensor is output when the difference between the first temperature and the second temperature is higher than a predetermined temperature difference threshold and the difference between the first relative humidity and the second relative humidity is lower than a predetermined humidity difference threshold.