3201 Lecture 1: Types of temperature measuring instruments
Document Summary
Temperature is defined as the energy level of a substance, which can be proved by certain changes in the substance. There are many types of temperature measurement sensors and they have one thing in common: they all measure temperature by sensing certain changes in physical properties. The most widely used device for measuring temperature is the liquid in glass thermometer, which to produce and simple to use. A glass bulb is connected to a sealed glass tube in the liquid in glass thermometer (also called the stem or capillary tube). A very thin opening called a bore runs down the center of the tube from the bulb. As the temperature rises, the bulb expands and rises up into the tube, and when the temperature falls, it contracts and moves down the tube. A liquid stored in a graduated glass envelope is the thermally sensitive factor in liquid in.
