The key difference between thermometry and thermography is that thermometry describes the measurement of the temperature of an object, whereas thermography describes the measurement of abnormally hot or cold areas on an object.
Both thermometry and thermography are important measurement techniques in chemistry that can be used to measure parameters regarding the temperature of an object. These two measurement techniques have applications in the field of analytical chemistry.
CONTENTS
1. Overview and Key Difference
2. What is Thermography
3. What is Thermography
4. Side by Side Comparison – Thermometry vs Thermography in Tabular Form
5. Summary
What is Thermometry?
Thermometry is the measurement of the temperature of an object. More precisely, it describes the measurement of the current temperature of an object for immediate or later evaluation. Thermometry includes repeated standardized measurements to assess the temperature trends of an object.
Many different methods can be used to measure the temperature of an object. Most commonly, these methods measure the variation of a particular property with the temperature. The most often used instrument for temperature measurement is glass thermometer. This glass thermometer contains a glass tube that is filled with mercury, and thus called mercury thermometer. Mercury acts as the working liquid, and its volume varies with the variation of temperature. For example, the volume of mercury expands with increasing temperature. However, this method measures temperature as a relative parameter to the volume of the working liquid. Therefore, thermometers are usually calibrated so that we can easily get a measurement. Another similar apparatus is the gas thermometer, which uses gas instead of a liquid.
Figure 01: A Mercury-filled Thermometer
There are many other techniques that can be used for the temperature measurement other than thermometers. Some examples include thermocouples, thermistors, resistant temperature detectors, pyrometers, Langmuir probes, etc.
What is Thermography?
Thermography is the process of measuring abnormally hot or cold areas on an object. This measurement is taken under normal atmospheric conditions so that the variations in temperature can be detected easily. The end result of the thermography is given as a thermogram.
A thermogram is a thermal image which displays the amount of IR energy emitted, reflected, or transmitted by an objected. Obtaining the readings using this method is difficult because there are multiple sources of IR radiation. However, a thermal imaging camera is capable of performing the algorithms and build an appropriate image by interpreting the data.
Figure 02: Thermal Imaging of Warm-Blooded Animals
A significant application of thermography is the thermal imaging of warm-blooded animals during clinical diagnostics. Therefore, it has applications in the field of medicine for allergy detection and in veterinary medicine.
What is the Difference Between Thermometry and Thermography?
Both thermometry and thermography are important measurement techniques in chemistry that can be used to measure the parameters regarding the temperature of an object. The key difference between thermometry and thermography is that thermometry describes the measurement of the temperature of an object, whereas thermography describes the measurement of abnormally hot or cold areas on an object. Moreover, thermometry uses thermometers as instruments, while thermography uses IR thermographic cameras.
The following table summarizes the difference between thermometry and thermography.
Summary – Thermometry vs Thermography
Both thermometry and thermography are important measurement techniques in chemistry that can be used to measure the parameters regarding the temperature of an object. The key difference between thermometry and thermography is that thermometry describes the measurement of the temperature of an object, whereas thermography describes the measurement of abnormally hot or cold areas on an object.
Reference:
1. “Thermometry.” WikiLectures, Available here.
2. “Temperature Measurement.” Wikipedia, Wikimedia Foundation, 8 May 2020, Available here.
Image Courtesy:
1. “Clinical thermometer 38.7” By Menchi – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Human-Infrared” By NASA/IPAC – Transwiki approved by: w:en:User:Dmcdevit This image was copied from wikipedia:en. – comes from a NASA “Cool Cosmos” website (Public Domain) via Commons Wikimedia
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