The vacuum in the other bulb allows free movement of the alcohol and mercury. It is the alcohol which measures the temperature; the mercury indicates the temperature reading on both scales. This is unlike a normal mercury thermometer, in which the expansion and contraction of mercury itself indicates temperature.
Hereof, which thermometer contains alcohol and mercury?
Temperature Measurement
The liquid-in-glass thermometer is a well-known temperature-measuring instrument that is used in a wide range of applications. The fluid used is normally either mercury or colored alcohol, and this is contained within a bulb and capillary tube, as shown in Figure 14.18(a).
Similarly, what is the difference between Mercury and alcohol thermometer? Mercury has a greater coefficient of thermal expansion than alcohol. This means a column of mercury will expand and rise more than a column of alcohol for the same temperature change. As a result, you can get finer readings with mercury. However, clinical mercury thermometers are on the decline.
Also Know, why is mercury and alcohol used in thermometers?
mercury and alcohol is used in thermometer because they expand at a fixed rate when it is heated , hence a slight change in temperature will increase the expansion a long way up the tube..
Are thermometers still made with mercury?
If the thermometer has silver liquid and is not labeled as “mercury-free,” assume it contains mercury. The non-silver liquid-in-glass thermometers typically contain a colored alcohol. The main health problems from mercury are from the vapors. These are produced at room temperature and especially when mercury is heated.
Related Question Answers
Where are alcohol thermometer used?
Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (−94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the freezing point of the liquid used.Why is mercury a good choice for thermometer?
Mercury is the only one in liquid state at room temperature. It's used in thermometers because it has high coefficient of expansion. It also has a high boiling point which makes it very suitable to measure higher temperatures. Also, it has a shiny appearance and doesn't stick to the glass surface of glass.What has replaced mercury in thermometers?
Non-mercury organic-liquid-filled-glass thermometers are also a replacement for mercury thermometers.How do you read an alcohol thermometer?
When reading the alcohol thermometer, make sure the eye position is level with the surface of the alcohol level. You will not observe a meniscus, as the alcohol level will be flat.Where are mercury thermometers banned?
While many people probably have them in their medicine cabinets, or on their walls, the retail sale of mercury thermometers has been banned or restricted in at least 18 states, including Washington, with more such legislation pending, according to the Interstate Mercury Education and Reduction Clearinghouse.How do mercury and alcohol thermometers work?
A thermometer has a glass tube sealed at both ends and is partly filled with a liquid like mercury or alcohol. As the temperature around the thermometer's bulb heats up, the liquid rises in the glass tube. When it is hot, the liquid inside the thermometer will expand and rise in the tube.What are the disadvantages of alcohol thermometer?
A thermometer comparison| advantages | disadvantages |
|---|---|
| Alcohol thermometer (compared to a mercury thermometer) | |
| lower freezing point (-114 C) | less durable (alcohol evaporates) |
| larger coefficient of expansion | alcohol can polymerise |
| less hazardous | fluid loss by evaporation hard to avoid |
Under what condition is it better to use alcohol instead of mercury in a thermometer?
Alcohol thermometers are used rather than mercury thermometers in very cold regions because alcohol has a lower freezing point than mercury. Pure ethanol freezes at -115 degrees C, while mercury freezes at -38 degrees C. Thermometers rely upon thermal expansion of the liquid in a bulb at the base of a thin glass tube.What happens if mercury touches you?
Direct contact with elemental (liquid) mercury can cause irritation and chemical burns. Possible immediate effects may include dizziness, vertigo, flu-like symptoms, burning or irritation, pale or clammy skin, irritability, and emotional instability.Why are mercury thermometers no longer used?
The reason: Mercury released into the environment from a broken thermometer is highly poisonous. Pure mercury and its compounds can cause neurological problems and other ailments in people exposed to them. Federal and state authorities have lobbied since 2002 for bans on medical mercury thermometers.What are the disadvantages of mercury?
The Weaknesses or the disadvantages of Mercury:- It cannot measure very low temperature, because its freezing point is high (-40ºC)
- Mercury is poisonous, so it harmful if its tube is broken.
- Its price is very high.
- display is harder to read.
- cannot be used for thermograph.
- slow response.
- fragile.
