what are most of todays thermometers made of?

Answer 1

There are many types of thermometers -- liquid in glass, bimetal, and an assortment of electronic-based sensors. The homemade thermometer design I provide here is based on the bimetal concept of measuring temperature, but instead of using metal strips, I use a strip taken from a discarded plastic bleach bottle and an equal length of "strapping" tape. The plastic and tape have different rates of expansion/contraction with temperature. And when they are fastened together the resulting strip will deform as the temperature changes. The cost to make this simple homemade thermometer is just a few pennies.

Putting it all together

Here is what I use to make this homemade thermometer:

(1) Strip of plastic from a bleach bottle, 2 to 4 inches long and as wide as the strip of strapping tape that will be used
(2) Length of strapping tape the same length and width as the plastic strip
(3) A cocktail straw
(4) Small block of wood 1/2" by 1/2" by 2"
(5) Small, stiff sheet of white cardboard
(6) A few thumbtacks

First, I cut out the plastic strip from a clean, rinsed bleach bottle and affix the tape to the inside cuve of the plastic strip. Note: If you make the curve of the plastic into a tight semicircle before affixing the tape, the deformation (i.e., sensitivity) of the strip will be much greater with temperature changes. I have done this by wrapping the plastic strip around a piece of metal pipe and gently heating it in the oven. This creates a nice tight plastic curve for me to attach the tape.

Next, I tape or glue a cocktail straw to one end of the plastic strip. Using a thumbtack, I then affix the sensor to a small block of wood. Finally, the block of wood is tacked to a small sheet of cardboard. See the diagram below for more information. Once completed, I test the instrument by simply breathing on it. My warm breath makes the cocktail straw move significantly downward.

Answer 2

The long glass ones are either alcohol or mercury. Probably only very old glass thermometers use mercury because of the perceived safety hazard.

But ... Has anyone actually seen a long glass thermometer outside of the laboratory lately??

I have an indoor/outdoor digital thermometer in the kitchen and a digital temp readout on the dash of my car. Plus I have three dial thermometers: a furnace thermostat thermom., a cooking thermom. in the kitchen, and one built into the gas grill outside.

Digital thermom. are usually of two types. Most common is the thermistor. This is a special resistor that changes resistance with temperature changes.

Another common type is the diode thermometer. This is an ordinary silicon diode with a tiny constant forward current. The voltage drop across the diode then changes with changing temperature.

Another that is uncommon outside the lab is the thermocouple thermom. It uses two wires made of dissimilar metals that are welded together at a point. Tiny voltages are amplified and measured at the other end of the two wires.

Finally, a dial thermom is made from two thin strips of dissimilar metal bonded together and bent into a spiral. As the temperature changes, the spiral coils or uncoils. An indicator needle is attached to the end of the spiral.

Answer 3

Since mercury is actually toxic, even in vapour form, most thermometers are made with an alcohol with red dye as the indicator of temperature.


Mercury thermometers are actually been taken out of schools and hospitals because the threat of breakage and mercury vapour released in the air. If one breaks, proper protocol is to use a respirator with a mercury filter while soaking up the liquid metal with an appropriate mercury absorbent. (You can buy kits)

The alcohol thermometers, though less harmful, are not as accurate nor responsive as the mercury thermometers.

Answer 4

What Are Thermometers

Answer 5

glass and alcohol with a red dye added.

There are very few mercury thermometers anymore

Answer 6

The ones that show a red line are alcohol with a red dye in it.

Mercury thermometers are also available and appear to be sivery.

Answer 7

Mercury is poisonous and has not been used in thermometers in many years.

They use red-dyed alcohol, nowadays.

Answer 8

They're digital mostly today.

They're definitely not made out of mercury. Those ones are very old, they discontinued using mercury for safety reasons. Mercury can be breathed in as a vapor and cause brain damage, and all kinds of foul stuff.

Answer 9

Ready made clothes. The only problem I've found is that a size eight dress always seems to be a little tight around the chest and shoulders but other than that everything is fine.

Answer 10

Mercury