information on different types of thermometers, their history along with photographs
Answers
Answer:
Types of thermometer
An ideal thermometer shall have infinite temperature range.Since no thermometer is ideal, therefore we have a large number of thermometers.
1.Mercury thermometer
mercury thermometer
It has linear expansion property and has a temperature range of -35°C to +500 °C(with compressed nitrogen).It works on the principle:
ΔL α ΔT
Where ΔT= Δl/lοα and α is the linear expansion coefficient.
2. Constant pressure gas thermometer
Constant pressure gas thermometer
In this thermometer, volume increases directly with the increase in temperature.It measures temperature in the range from o k 5oo k.
ΔV α ΔT
Where ΔT=ΔV/Vογ=ΔV×273/Vο
And γ=1/273 for ideal gases.
3. Constant volume thermometer
In this thermometer pressure increases directly with the increase of temperature.It measures temperature in the range o k to 5oo k.
ΔP α ΔT
where ΔT=Δp/P triple point γ
=273 Δp/P triple point
4.Platinum resistance thermometer
In this thermometer resistance of material in thermometer increases directly with increase of temperature.It measures temperature in the range of 5oo k to 2300 k.
ΔR α ΔT
where ΔT=ΔR/Rα , α is thermal coefficient of resistance.
5. Thermocouple thermometer
This thermometer work on the principle:
emf ∈ = αT +β T²
In this scale is nonlinear.Temperature is either matched with a standard curve supplied by the manufacturer or a digital display is provided.α and β depend upon the materials used to form thermocouple. where:
emf ∈=αT + βT²/2
It measures temperature in the range 500 k to 2300 k
6.Pyrometer
This thermometer work on the principle of radiation.It measures temperature greater than 2000 k.It uses Stefan’s law:
Intensity E= σT4
HISTORY
What is a Thermoscope?
Before there was the thermometer, there was the earlier and closely related thermoscope, best described as a thermometer without a scale. A thermoscope only showed the differences in temperatures, for example, it could show something was getting hotter. However, the thermoscope did not measure all the data that a thermometer could, for example, an exact temperature in degrees.
Early History
Several inventors invented a version of the thermoscope at the same time. In 1593, Galileo Galilei invented a rudimentary water thermoscope, which for the first time, allowed temperature variations to be measured. Today, Galileo's invention is called the Galileo Thermometer, even though by definition it was really a thermoscope. It was a container filled with bulbs of varying mass, each with a temperature marking, the buoyancy of water changes with temperature, some of the bulbs sink while others float, the lowest bulb indicated what temperature it was.
In 1612, the Italian inventor Santorio Santorio became the first inventor to put a numerical scale on his thermoscope. It was perhaps the first crude clinical thermometer, as it was designed to be placed in a patient's mouth for temperature taking.
Neither Galileo's nor Santorio's instruments were very accurate.
In 1654, the first enclosed liquid-in-a-glass thermometer was invented by the Grand Duke of Tuscany, Ferdinand II. The Duke used alcohol as his liquid. However, it was still inaccurate and used no standardized scale.
For photos you can use google.
Hope it may help you...
Answer There are many different types of thermometer available in today's market. Before you make your purchase, it is vital that you are made aware of the range of products available to you. You should also understand and consider each type of thermometers suitability for various different uses. Complying with safe storage regulations in a catering establishment will require a very different thermometer to manufacturing of goods. Just as a generic office or workplace thermometer is not suitable for critical industrial measurements. At ATP we believe it is important to choose the right thermometer to suit your intended application. So let's take a look at the different thermometers we offer and their ideal uses
View types of thermometers at our webstore
Probe Thermometers
Infrared Thermometers
K-Type Thermocouples
Temperature Data Loggers
Analogue Thermometers
Thermal Imaging Cameras