Glass stem thermometer
The glass stem thermometer is one of the oldest instruments for measuring temperature. In this method, mercury or alcohol is used in a glass tube, which expands with increasing temperature and moves inside the tube, although the air inside the tube is evacuated. In some applications, the glass tube is filled with nitrogen to increase the operating temperature range.
The material used in the glass stem thermometer must remain liquid in the working range. Mercury has a wide range of functions and is quite suitable for this purpose. Alcohol is used at lower temperatures. Since alcohol is transparent, it is used to increase the visibility of that color.
In order to increase the usability and mechanical protection of glass stem thermometers in automatic control systems and also due to the toxicity of mercury, they are less used today. Thermometers are very cheap temperature displays and may still be found in older systems.
Advantages
*low cost
* Simplicity
* No need for re-calibration
Disadvantages
* Measure only locally
* Separate from other control and local equipment
* Fragile
Mercury thermometer, alcohol thermometer, mercury temperature gauge, alcohol temperature gauge
Rose Calibration Company in Melbourne, Australia with over ten years of experience provides all calibration, maintenance, and repair services throughout Australia. If you live in Sydney, Melbourne, Adelaide, Perth, Geelong, and Brisbane, you can receive your quote in less than two hours by fill-up the form via the “Booking” link.