Temperature-controlled bath

A linear expansion coefficient measuring device comprising:

• a temperature-controlled bath;
• measurement means for measuring a length of the sample at different temperatures;
• and calculation means for calculating a coefficient of linear expansion of the sample based on the length of the sample at each temperature, wherein
• the temperature-controlled bath comprises:
• temperature changing means for heating or cooling a gas so that the temperature of the gas is adjusted to a set temperature;
• a temperature-controlled chamber whose temperature is adjusted by the temperature changing means, the temperature changing means being disposed in the temperature-controlled chamber;
• a sample holding chamber containing a sample therein, the sample holding chamber being separated from the temperature-controlled chamber by a thermally conductive wall;
• and
• connection cut-off means for changing a connection between the temperature-controlled chamber and the sample holding chamber to a connected state or a cut-off state.

A temperature-controlled bath comprising:

• a temperature changing unit that heats or cools a gas so that the temperature of the gas is adjusted to a set temperature;
• a temperature-controlled chamber whose temperature is adjusted by the temperature changing unit, the temperature changing unit being disposed in the temperature-controlled chamber;
• a sample holding chamber containing a sample therein, the sample holding chamber being separated from the temperature-controlled chamber by a thermally conductive wall;
• and
• a connection cut-off unit that changes a connection between the temperature-controlled chamber and the sample holding chamber to a connected state or a cut-off state.