| abstract |
A thermal sensor in which, when an object to be measured is a water-based liquid, attachment of air bubbles to the external surface of the sensor is reduced to improve measurement accuracy. The thermal sensor has a sensing element ( 21 a ) including a heat producing body and a temperature sensing body, a resin mold ( 23 ) for sealing the sensing element ( 21 a ), and a heat transmission member ( 21 c ) for transmitting heat between the sensing element ( 21 a ) and a water-based object to be measured. A part of the heat transmission member ( 21 c ) is exposed from the resin mold ( 23 ) to form an exposed surface section. A hydrophilic film ( 50 ) formed of a silicon oxide film is applied to the exposed surface section and to that part of the surface of the resin mold which is positioned around the exposed surface section. |