HYGROMETER AND TEMPERATURE-HUMIDITY CHAMBER PROVIDED WITH SAME

• US 20150068283A1
• Filed: 03/06/2013
• Published: 03/12/2015
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Espec Corporation
• Original Assignee: Espec Corporation
• Inventors: Yamauchi, Satoru
• Granted Patent: US 10,481,078 B2
• Time in Patent Office: Days
• US Class Current: 73/29.02
• CPC Class Codes: G01N 19/10 Measuring moisture content, e.g. by measuring change in length of hygroscopic filament; Hygrometers
• CPC Class Codes: G01N 25/66 by investigating dew-point

Abstract

A hygrometer includes a heat transfer section extending from a measurement space toward an outside space separated from the measurement space, a heat release amount control unit that causes heat to be released to the outside space from the heat transfer section such that an amount of heat released to the outside space is made constant, and a computation device that calculates a humidity of the measurement space. The computation device calculates the humidity from a heat transfer section temperature and a measurement space temperature using a relational expression based on a heat balance in the heat transfer section when condensation is occurring in a portion, of the heat transfer section, located within the measurement space in a state where the amount of heat released to the outside space from the heat transfer section is made constant by the heat release amount control unit.

Claims

1. A hygrometer that measures a humidity of a measurement space, comprising:

a heat transfer section extending from the measurement space toward an outside space separated from the measurement space by a thermal insulation section;

a heat release amount control unit that causes heat to be released to the outside space from the heat transfer section such that an amount of heat released to the outside space is made constant; and

a computation device that calculates a humidity of the measurement space,

wherein the computation device calculates a humidity of the measurement space from a temperature of the heat transfer section and a temperature of the measurement space using a relational expression based on a heat balance in the heat transfer section when dew formation is occurring in a portion, of the heat transfer section, located within the measurement space in a state where the amount of heat released to the outside space from the heat transfer section is made constant by the heat release amount control unit.

2. The hygrometer according to claim 1, comprising a heat transfer section temperature detection unit that detects a temperature of the heat transfer section,

wherein the computation device uses a temperature detected by the heat transfer section temperature detection unit as the temperature of the heat transfer section.

3. The hygrometer according to claim 1, comprising a measurement space temperature detection unit that detects a temperature of the measurement space,

wherein the computation device uses a temperature detected by the measurement space temperature detection unit as the temperature of the measurement space.

4. The hygrometer according to claim 1, wherein the heat release amount control unit includes a Peltier element and a power supply unit that supplies power to the Peltier element,

the Peltier element is arranged to be capable of cooling the heat transfer section, and

the power supply unit is capable of supplying constant power to the Peltier element.

5. The hygrometer according to claim 4, wherein the Peltier element is arranged to surround, together with the thermal insulation section, a portion of the heat transfer section other than the portion located within the measurement space.

6. The hygrometer according to claim 1, wherein the heat transfer section protrudes toward the outside space side from the thermal insulation section, and

the heat release amount control unit includes an air supply section that forms a flow of air toward a portion of the heat transfer section protruding toward the outside space side, and a temperature adjustment section that makes a temperature of air supplied to the protruding portion by the air supply section constant.

7. A temperature-humidity chamber comprising:

a thermal insulation section that surrounds a predetermined measurement space;

the hygrometer according to claim 1 that measures a humidity of the measurement space; and

a temperature and humidity adjustment section that adjusts at least one of a humidity and a temperature within the measurement space on the basis of a result of measurement by the hygrometer.

8. A hygrometer that measures a humidity within a space, comprising:

a heat transfer section extending from a first end section arranged in a first position within the space up to a second end section arranged in a second position that is apart from the first position, and capable of heat transport of heat that has entered the first end section from the space to the second end section;

a heat release amount control unit that causes heat to be released to the space from the second end section of the heat transfer section such that an amount of heat released to the space is made constant; and

a computation device that calculates a humidity of the space,

wherein the computation device is configured to calculate a humidity of the space from a temperature of the heat transfer section and a temperature of the space using a relational expression based on a heat balance in the heat transfer section when dew formation is occurring at least in the first end section in a state where the amount of heat released to the space from the second end section is made constant by the heat release amount control unit.