Thermometers and conman types
We hear that matter expands when heated and this expansion is not always linear. We also know that alcohol and mercury were initially the liquids used for the construction of thermometers. Clearly, not all thermometers are built this way, but because they are the most common, we’ll start them: the thermometers of this type consist of a glass tube with an inner diameter very small (capillary) soldier a glass sphere containing the liquid selected. The more liquid, the expansion of warming is more noticeable and therefore the rise in the capillary tube, easier to observe.
Surely you have thought that if the bodies expand by heat, it also thins the glass in which is contained the liquid. Will it change the fact the accuracy of the measurement? Dilatation of the glass scale is so small that we can dismiss it, only for very accurate to be used other methods. It is important to consider that for this reason the readings in glass thermometer with an accuracy of 0.01 K.
All liquids freeze and boil at specific temperatures, therefore, each thermometer is designed for specific temperature ranges. In the case of mercury, its freezing point is -39.0 ° C and the boiling point is 356.7 ° C, values ??that limit their range of application. For the same reason, an alcohol thermometer works only in a range from -100 ° C to 70 ° C. Here are the list of some common thermometers
- Gas thermometer
- Platinum resistance thermometers
- Several thermometric probes for use with a digital thermocouple thermometer laboratory
- The temperature inside a furnace is measured with a thermometer or pyrometer radiation
- EXPANSION THERMOMETERS
- Bimetallic strip thermometer
- Thermometers filled systems
- Gas filled thermometers
- Thermometers vapor pressure
- Thermometer pressure steam pressure-sensitive element
- Liquid expansion thermometers