US 5,756,878 A · Thermal conductivity measuring device

Abstract

A thermal conductivity measuring device includes a diaphragm portion, a thermal conductivity detector, a temperature sensor, a control section, and a thermal conductivity calculating section. The diaphragm portion is formed on a base. The thermal conductivity detector is formed in the diaphragm portion to perform conduction of heat to/from a sample gas. The temperature sensor is disposed on the base to be near the thermal conductivity detector so as to measure the ambient temperature around the base. The temperature sensor is thermally insulated from the thermal conductivity detector. The control section controls the amount of energy supplied to the thermal conductivity detector such that the temperature difference between the ambient temperature measured by the temperature sensor and the heating temperature of the thermal conductivity detector becomes a constant value. The thermal conductivity calculating section calculates the thermal conductivity of the sample gas on the basis of the amount of energy supplied to the thermal conductivity detector while the temperature difference is kept at the constant value by the control section.

Claims10

Dependent claims

A device for measuring the thermal conductivity of a sample gas, comprising:

a diaphragm formed on a base;
a thermal conductivity sensor formed on said diaphragm and coupled to said sample gas so that heat generated by said thermal conductivity sensor is transferred between said thermal conductivity sensor and said sample gas;
temperature measuring means, disposed on said base near said thermal conductivity sensor, for measuring an ambient temperature around said base, said temperature measuring means being thermally insulated from said thermal conductivity sensor;
means for supplying electrical energy to said thermal conductivity sensor;
means for controlling the electrical energy supplied to said thermal conductivity sensor so that a temperature difference between the temperature of said thermal conductivity sensor and said ambient temperature measured by said temperature measuring means is a constant, predetermined value;
thermal conductivity calculating means for calculating a thermal conductivity of the sample gas on the basis of the electrical energy supplied to said thermal conductivity sensor to achieve said temperature difference of said constant predetermined value.

3 more elements

Dependencies are inferred from the claim text.

Thermal conductivity measuring device

Life of this patent

Thermal conductivity measuring device

Life of this patent

Abstract

Claims10