Can you still buy a mercury thermometer?
What Will Replace Them? The National Institute of Standards and Technology (NIST) announced last week that it would stop calibrating mercury thermometers starting March 1 a move that brings the U.S. one step closer to phasing out these temperature-measuring devices for good.
Why do we not use a laboratory thermometer to measure body temperature?
A laboratory thermometer cannot be used to measure the human body temperature. This is because as soon as we take out the bulb of the laboratory thermometer from our mouth, the level of mercury in its tube will start falling quickly. This will give a wrong value of the body temperature.
Which is better mercury or digital thermometer?
1. Digital thermometers provide faster results. Digital thermometers provide fast results as opposed to mercury thermometers whose readings are slower to realize because you have to wait for the mercury to heat and then slowly rise to display the temperature.
Why do you use mercury instead of alcohol in a thermometer?
There is a technical reason for using mercury in clinical thermometers. 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.
Is it bad to breathe Mercury in a thermometer?
Mercury vapor is not irritating and has no odor, so people do not know when they are breathing it. Even the small amount of mercury from a broken thermometer can cause harm, especially to children, unless it is properly cleaned up and removed. Are alcohol thermometers more accurate?
Why did Fahrenheit use a mercury thermometer?
Moving from Hg thermometers. Today, there is no scientific or metrological reason to employ mercury thermometers for any application. That may come as a surprise. Fahrenheit chose mercury because it gave more precise readings over a wider range than the alcohol mix he used in his first thermometer.
Is there an ASTM equivalent to a mercury thermometer?
ASTM Equivalent Non-Mercury Thermometers have the same physical and performance characteristics as ASTM Non-Mercury Thermometers and the same ranges and divisions as ASTM Mercury-filled thermometers but have not yet been reviewed by ASTM subcommittees for their referenced applications.