Fahrenheit scale

Temperature. Temperature maybe measured on an absolute or relative scale. The two most common relative scales are the Celsius and the Fahrenheit scales. The Celsius scale is defined as 0°C at the freezing point (triple point) of water and 100°C at the boihng point. The Fahrenheit scale is arbitrarily defined by assigning it a temperature of 32 degrees at the freezing point of water and 212°F at the boihng point of water (see Temperature measurements). 

The absolute temperature scale that corresponds to the Celsius scale is the Kelvin scale for the Fahrenheit scale, the absolute scale is called the Rankine scale. The Celsius scale reads 0 when the Kelvin scale reads 273 the Fahrenheit scale reads 0 when the Rankine scale reads 460. These relationships are shown in Figure 1. 

Fahrenheit or Centigrade scales. The absolute Fahrenheit scale is called Rankine and the absolute Centigrade is called Kelvin. For conversion ... 

Enthalpy may be expressed as a total above absolute zero, or any other base which is convenient. Tabulated enthalpies found in reference works are often shown above a base temperature of - 40°C, since this is also - 40° on the old Fahrenheit scale. In any calculation, this base condition should always be checked to avoid the errors which will arise if two different bases are used. 

The Fahreuheit and Celsius temperature scales. The distance between the freezing and boiling points of water is 180° on the Fahrenheit scale and 100° on the Celsius scale. Thus the Celsius degree is 9/5 as large as the Fahrenheit degree, as is evident from the magnified section of the thermometer above. 

Two scales used in die measuring of temperatures are Fahrenheit (F) and Celsius (C) (also known as centigrade). On the Fahrenheit scale, die freezing point of water is 32° F and die boiling point of water is 212° F. On die Celsius scale, 0° C is the freezing point of water and 100° C is die boiling point of water. 

The Fahrenheit scale, in which water freezes at 32 °F and boils at 212 °F, is still in common use in the United States, but scientists rarely use the Fahrenheit scale. The formula for converting temperature from Fahrenheit to Celsius is... 

The intensity of heat, or temperature, is measured in Celsius (centigrade) or Fahrenheit scales, and expressed in degrees (°). The instrument that measures the temperature is called thermometer. Most thermometers in the United States use the Fahrenheit scale. 

A comparison of Celsius and Fahrenheit scales is shown in Figure D.l. 

To convert the temperature from Fahrenheit scale to Celsius scale, the following expression may be used ... 

Rankine Temperature Scale A temperature scale with the size of degree equal to that of the Fahrenheit scale and zero at absolute zero. Therefore 0°R = -459°F (-273,2°C) and the normal boiling point of water is 671.67°R. 

Three different scales are in common use for measurements of temperature the Celsius scale (expressed in degrees Celsius, or °C), the Fahrenheit scale (expressed in degrees Fahrenheit, or °F), and the Kelvin scale (expressed in kelvins, or K). The Fahrenheit scale is commonly used in daily life and in engineering work. The Celsius scale is used in scientific work and is coming into common usage in daily life in English-speaking countries. The Kelvin scale (also called the absolute scale) is the SI choice for temperature measurements, and it is widely used in scientific work. 

If the readings on the Imaginary scale are now expressed in terms of the readings on the Fahrenheit scale, we shall have the formula to convert from Fahrenheit to Celsius given in Table 4-2. That is,... 

ABSOLUTE ZERO. Conceptually that temperature where there is no molecular motion, no heat. On the Celsius scale, absolute zero is -273.15°C, on the Fahrenheit scale, —459.67°F and zero Kelvin (0 K). The concept of absolute zero stems from thermodynamic postulations,... 

Fahrenheit scale A temperature scale on which the freezing point of water is at 32 degrees and the normal boiling point is at 212 degrees. Units on this scale are degrees Fahrenheit, °F. 

At a certain point, the Celsius and Fahrenheit scales "cross," giving the same numerical value on both. At what temperature does this crossover occur ... 

The Rankine temperature scale used in engineering is to the Fahrenheit scale as the Kelvin scale is to the Celsius scale. That is, 1 Rankine degree is the same size as 1 Fahrenheit degree, and 0°R = absolute zero. 

On the Celsius (or centigrade) scale, a temperature difference of 1°C is 1 K (exactly). The normal boiling point of water is 100°C, the normal freezing point 0°C, and absolute zero -273.15°C. On the Fahrenheit scale, a temperature difference of 1°F is 5/9 K (exactly). The boiling point and freezing point of water, and absolute zero are 212°F, 32°F and -459.67°F, respectively. Conversions from one temperature scale to another make use of the following equations ... 

In these equations, we have used a particularly convenient notation t/°C, T/K, and t/°F refer to the numerical values of temperatures on the Celsius, Kelvin, and Fahrenheit scales. By dividing the temperature in degrees Celsius by 1°C, we obtain a pure number. 

A difference of one degree on the Fahrenheit scale is exactly 5/9 K. The normal boiling point of water is 212°F the normal freezing point of water is 32°F and absolute zero is -459.67°F. 

Ethyl alcohol (a) boils at 78.5°C and (b) freezes at —117°C, at one atmosphere of pressure. Convert these temperatures to the Fahrenheit scale. 

Gold has been mined and refined for many thousands of years, certainly before electric furnaces and other high-temperature devices were possible. The melting point of gold is 1064°C express this temperature in terms of the Kelvin and Fahrenheit scales. 

An accelerant is suspected when a vehicle fire is so hot that the glass in the windshield melted. The melting point of this car s glass (essentially Si02) is 1698°C. Convert that temperature to (a) the Kelvin scale and (b) the Fahrenheit scale. 

A patient has a temperature of 310 K. Should you be concerned Or rather, what is the patient s temperature on the Fahrenheit scale ... 

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