# Temperature Measurement

Improved Essays
This module will help you understand the applications of temperature measurement in industry as well as help you develop skills to convert temperature between common scales. It also discusses the thermal expansion principles used by some temperature measurement instruments. You will also learn about thermal contact and its effect on the accuracy and response time of temperature sensors, and about thermowells and their purpose.

Objective One
When you have completed this objective, you will be able to:
Explain why and where temperature measurement is used in industry.
Temperature Measurement
Temperature expresses the common notions of hot and cold. Objects of low temperature are cold, and various degrees of higher temperatures are warm or
Temperature Measurement Terms
Temperature measurement is an important parameter in monitoring and controlling processes in industry. You must understand the terms related to temperature measurement.
Temperature
Temperature is a measure of the average kinetic energy of the particles in an object; kinetic energy is the rate at which molecules or particles move. When particles of any matter (solids, liquids, gases or elementary plasmas) move faster, they carry more kinetic energy and feel warmer than a material with slower particles.
Boiling
Boiling is the process where molecules transition from the liquid phase to the gas phase, resulting in the formation of vapour bubbles within the liquid (Figure 1).

Figure 1 – Liquid changing to a gas.
Boiling Point
Boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure that surrounds the liquid. At boiling point, the vapour pressure of the liquid becomes sufficient to overcome atmospheric pressure and lift the liquid to form bubbles inside the bulk of the liquid. For example, at standard atmospheric pressure of 101.325 kPaa, the boiling point of water is 100C
For example, water requires 2257 kJ/kg (970 BTU/lb) to change to steam. Steam gives up 2257 kJ/kg (970 BTU/lb) when it condenses back to water. The temperature stays constant during these phase changes (Figure

## Related Documents

• Improved Essays

Rankine cycle Figure 2: Rankine cycle As mentioned earlier, the Rankine cycle also includes the possibility of superheating the vapor, as cycle 1–2–3–4–1. If changes of kinetic and potential energy are neglected, heat transfer and work may be represented by various areas on the T–s diagram. The heat transferred to the working fluid is represented by area a–2–2–3–b–a and the heat transferred from the working fluid by area a–1–4–b–a. From the first law we conclude that the area representing the work is the difference between these two areas—area 1–2–2–3–4–1. The thermal efficiency is defined by the relation For analyzing the Rankine cycle, it is helpful to think of efficiency as depending on the average temperature at which heat is supplied and the average temperature at which heat is rejected.…

• 766 Words
• 4 Pages
Improved Essays
• Superior Essays

The mass of the substance was measure on a scale balance. Also the temperature of the substance (water or metal) was measured using a thermometer at a given time. A pre-heated immersion heater was placed in the substance and allowed to cool off. Therefore in the case heat was being transferred from the heater to the substance (water/ metal). The specific heat capacity was calculated.…

• 2159 Words
• 9 Pages
Superior Essays
• Improved Essays

The thermometer will accumulate condensation and will accurately measure the boiling point of the collected compound. After the more volatile compound is collected, the heat is increased in order to determine the boiling point of the second compound. The boiling point of the compounds is observed by a plateau in temperature…

• 1011 Words
• 5 Pages
Improved Essays
• Superior Essays

The Calorimetric Determination of Enthalpy and Entropy Changes of the Thermal Decomposition of Sodium Sulphate Decahydrate Abstract Sodium sulphate decahydrate thermally decomposes to anhydrous sodium sulphate at 50⁰ C and cools to form anhydrous sodium sulphate. Using Hess's Law the enthalpy and entropy changes of this process can be determined in order to deduce the spontaneity of the reaction. The transition temperature was determined by melting the hydrated crystals at 50⁰ C and allowing them to cool until a constant temperature was reached. The molar enthalpy and molar entropy changes were determined using calorimetric principles. Different weights of both decahydrate and anhydrous crystals were added to water and the temperature changes…

• 1185 Words
• 5 Pages
Superior Essays
• Improved Essays

Double diffusive convection phenomenon occurs in situations where flow is driven by solutal gradients apart from thermal gradients. Present days in industrial processes like food processing, drying, chemical vapour deposition etc. the nature of fluid flow with in the process chambers largely governs the outcome. Thus research on double diffusive convection flows in relations to various applications in many mechanical and chemical engineering industries and also in fields like oceanography, nuclear technology, renewable energy etc [1-6] became admirable. The research reported in context to double diffusive convection are as flows: Coasta et al.…

• 988 Words
• 4 Pages
Improved Essays
• Improved Essays

The instability starts near the interface and causes a sinuous movement to the interface. At higher temperature gradients, the instabilities increase and the movement becomes continuous. When temperature gradients are a sinuous wave was observed [26]. Also, when the concentration at the interface is less than the concentration at the slot the surface tension at the free surface accordingly reduces. This implies that the surface tension is inversely proportional…

• 899 Words
• 4 Pages
Improved Essays
• Improved Essays

At : B.C.2: At the solid-air interface, the heat transferred from air to solid by convection is consumed in changing the solid temperature and evaporating the moisture at the solid surface. At : Equation (2) with its boundary conditions can be solved using finite difference method. Another method of solution is using the collocation method. Simply; this method assumes that the temperature profile within the solid particle can be expressed as a binomial of the second degree, function in two collocation points; the surface collocation point at and an interior collocation point at where their temperatures are nominated (Ti) and (T1) respectively. The collocation method is explained in details in appendix A.…

• 1160 Words
• 5 Pages
Improved Essays
• Superior Essays

Various components of the gas turbine were specifically designed to perform individual functions separately. These functions are known as Intake, Compression, Combustion, Expansion, and Exhaust. The Brayton cycle can also be better explained as air entering the inlet at atmospheric pressure and constant volume. As the air passes through the compressor, it increases in pressure and decreases in volume. Combustion occurs at constant pressure while the increased temperature causes a sharp increase in volume.…

• 1872 Words
• 8 Pages
Superior Essays
• Great Essays

In convection, warm particles move to a region with substance at a lower temperature and particles transfer heat by colliding with the cooler particles (Sukhatme, 2005). As it collides the warm particles lose heat to become cooler whereas cool particles gain heat to become warmer. This cycle repeats, occurring in circular motion (The Physics Classroom, 2015). An example of this is shown by the heat transfer through water in a heated pot on a stove. As the metal pot becomes hotter, it begins to conduct heat to the water.…

• 1176 Words
• 5 Pages
Great Essays
• Great Essays

Abstract The purpose of this experiment is to determine the relationship between the temperature and pressure of air at constant volume which placed the Jolly’s bulb in water of different temperature. At the constant volume of the air in the Jolly’s bulb, the temperature and pressure of the air are measured and recorded throughout the experiment. The result shows that the pressure of the air in the Jolly’s bulb increases as the temperature rises, and the pressure decreases as the temperature decreases. After plotting the graph manually according to the data obtained from the experiment, it shows that the pressure of air is linearly proportional to the temperature of air at constant volume. In order to obtain the value of absolute zero from…

• 1745 Words
• 7 Pages
Great Essays