Clinical Thermometer

Clinical thermometer is a slight modification of mercury thermometer. It is specially designed to measure the human body temperature. Structure: It is smaller in size than the laboratory thermometer. It has a constriction in the fine capillary tube. This constriction prevents the mercury from contracting and flowing back when it is removed from human body (temperature of surroundings being lower). …

Read more

Laboratory thermometer

Structure: The thermometer is made relatively small so that it is portable and cheap. The liquid is contained in a thin-walled glass bulb. The bulb is made relatively larger than its bore to contain more of the liquid, so as to improve sensitivity. The narrow bore of the capillary tube is uniform. The round glass stem around the capillary tube …

Read more

Defining A Temperature Scale

A thermometer is useless without a temperature scale (the markings on the thermometer). In order to define a temperature scale, the following steps are required: Choose a thermometric substance with a suitable thermometric properties. Select two fixed points which are easily obtainable and reproducible. (Fixed points are explained in more details below.) Divide the temperature range between the two fixed …

Read more

Thermometric Property

An instrument, a thermometer, is required to measure temperature objectively. The thermometer makes use of a physical property of a thermometric substance which changes continuously with temperature. The physical property is referred to as thermometric property. Thermometric Properties Used In Various Thermometers The following table shows some of the thermometric properties of matter that are used in the various thermometers: …

Read more

Thermometry

Thermometry (Aka. temperature measurement) is essential to a wide range of activities, including manufacturing, scientific research, and medical practice. The ability to measure temperature accurately was only developed recently. Temperature (like mass, length, time) is a chosen fundamental quantity. Therefore, arbitrarily chosen units (such as degrees Celsius, degrees Fahrenheit or Kelvin) are used to measure temperature. Temperature is measured quantitatively …

Read more

Application of Radio Waves

Radio waves can be used to carry messages and simple television pictures at very large distances. Radio-waves are grouped into bands; each band has particular nature and special set of uses: http://en.wikipedia.org/wiki/Radio_spectrum In order to reach greater distances than line of sight, some radio waves can be made to travel towards the sky. (sky waves) The waves are then refracted …

Read more

The Electromagnetic Spectrum

The spectrum of the radiation emitted by a hot body is continuous because there are many different kind of oscillators in any real lump of matter, so that in practice radiation exists at all frequencies. The main components of the electromagnetic spectrum are gamma-rays, x-rays, ultra-violet, visible light, infra-red, microwaves and radio-waves. Gamma-rays and X-rays are the highest-energy electromagnetic waves …

Read more