What is the purpose of a bimetal thermometer?

The purpose of a bimetal thermometer is to measure the temperature of a fluid. This device consists of two different metals that expand at different rates when heated. As the temperature changes, the bimetallic strip bends due to the differential expansion of the two metals, which then moves a pointer on a dial to indicate the temperature. This makes it a reliable and practical instrument for measuring temperatures in various applications, including those in refrigeration systems where monitoring the temperature of fluids is essential for effective operation and safety.

The other options do not align with the function of a bimetal thermometer. For example, controlling pressure in a system is typically the job of pressure gauges or regulators, while converting thermal energy into electrical energy is a function related to thermoelectric devices, such as thermocouples or thermoelectric generators. Sensing the level of a refrigerant would involve level sensors or floats, not a thermometer designed primarily for temperature measurement. Each of these functions is distinct and relies on specialized devices designed for those tasks.