Patent ID: 7934868

Claim:
A measurement device comprising: a thermal sensor; and a calculation section electrically coupled to the thermal sensor, wherein the thermal sensor comprises: a sensing element including a heater and a temperature sensor that senses heat generated by voltage application to the heater; a resin mold that seals the sensing element; a heat transfer member exposed from the resin mold that performs heat transfer between the sensing element and an aqueous liquid to be measured, a base body to which the resin mold is fixed; and a heat transfer member cover member attached to the base body and surrounding the heat transfer member so as to form therebetween a flow passage for the aqueous liquid to be measured, wherein a part of the heat transfer member is exposed to the flow passage so as to form a first exposed surface portion, a part of the resin mold is exposed to the flow passage so as to form a second exposed surface portion, and at least one of the first exposed surface portion, the second exposed surface portion and an inner surface portion of the heat transfer member cover member exposed to the flow passage is hydrophilic, and wherein the calculation section calculates a characteristic value of the aqueous liquid to be measured based on a first value of output of the thermal sensor obtained by averaging a predetermined number of samples from the output of the thermal sensor at a first predetermined time period prior to starting the voltage application and a second value of output of the thermal sensor obtained by averaging a predetermined number of samples from the output of the thermal sensor at a second predetermined time period prior to stopping the voltage application to the heater.