Which two liquids are used in the construction of liquid in glass thermometers?
The two common liquids used in liquid-in-glass thermometers are alcohol (ethanol) and mercury, which have melting points and boiling points of -114 C, 79 C and -39 C, 357 C, respectively. Which one of these thermometers would be better for low temperature measurements?
What is the liquid in glass thermometer used for?
The liquid in glass thermometer, is the most commonly used device to measure temperature and it is inexpensive to make and easy to use. The liquid in glass thermometer has a glass bulb attached to a sealed glass tube (also called the stem or capillary tube).
Why is water not used in the construction of liquid in glass thermometer?
Water is not able to be used as a thermometer liquid because of its higher freezing point and lower boiling point than the other liquids in general. If water is used in a thermometer, it will start phase variation at 0∘C and 100∘C. This will not help in measuring temperature, beyond this range.
What liquid is used inside most glass thermometers?
In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. Mercury thermometers can be used to determine body, liquid, and vapor temperature.
What liquids are used in thermometers?
Mercury is one of the most familiar materials used in liquid thermometers. Other liquids, such as kerosene or ethanol, may also be used in these types of thermometers. When heat rises, the liquid expands from a bowl or bulb into the empty area, climbing up the tube.
What is liquid-in-glass thermometer discuss its advantages and disadvantages?
Mercury was the liquid the most often used because of its good reaction time, repeatability, linear coefficient of expansion and large temperature range. But it is poisonous and so other working liquids are used….
| THE LIQUID-IN GLASS THERMOMETER | |
|---|---|
| Advantage | Disadvantage |
| easy to use & cheap | cannot be digitised or automated |
Why only alcohol and mercury is used inside glass thermometers and why can’t water be used instead?
And a water thermometer will break when the temperature drops below 0°C, since water expands when freezing. Mercury or alcohol thermometers may break when exposed to too high temperatures, but too low isn’t a problem.
Which of the following fluid is not used in liquid in glass thermometer?
Water cannot be used as a liquid in a thermometer.
Which two liquids are used inside a traditional thermometer?
The liquids found in most thermometers are mercury, alcohol or a hydrocarbon. Special care must be taken when a mercury thermometer is broken as mercury vapor is toxic.
What liquid is used in thermometers?
Mercury
Mercury is the only one in liquid state at room temperature. It’s used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer. It also has a high boiling point which makes it very suitable to measure higher temperatures.
How does a liquid in glass thermometer work?
In the Liquid In Glass Thermometers (LIG) the thermally sensitive element is a liquid contained in a graduated glass envelope. The principle used to measure temperature is that of the apparent thermal expansion of the liquid. A typical liquid-in-glass thermometer is shown in the figure below.
What are the different types of glass thermometers?
EXPERIMENTAL TECHNIQUES 1 Liquid-in-Glass Thermometers. Liquid-in- glass thermometers measure the thermal expansion of a liquid, which is placed in a solid container, on a length scale. 2 Filled Thermometers. 3 Bimetallic Thermometers
What makes up the bulb of a thermometer?
As illustrated in Figure 1, the bulb of the thermometer is the thin glass reservoir that holds the liquid. The bulb is carefully designed to contain a calculated volume of liquid, based upon the length and diameter of the capillary (or stem), as well as the thermal expansion coefficient of the liquid.
Which is ASTM specification for liquid in glass thermometer?
ASTM has developed a specification for low-hazard precision LiG thermometers, ASTM E 2251, Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids. This standard provides specific details on proper use of these devices, the repeatability of their measurements, and other limitations.