Trade related science; Chapter 2 homework, test material

Flashcards covering vocabulary and core concepts of thermodynamics, heat measurement units, temperature scales, and heat transfer mechanisms based on the lecture transcript.

Melting point

The point reached when a solid absorbs a sufficient quantity of latent heat of fusion and changes state to a liquid.

Bimetal thermometer

A thermometer that measures temperature by the movement in a bimetal strip or coil caused by a change in temperature.

Forced convection

A process that uses fans and blowers to create air movement when systems require a relatively immediate heat transfer to take place.

British thermal unit (BTU)

A unit used to measure the quantity of heat.

Thermistor

A type of thermometer that operates on the principle that resistance to the flow of electric current increases as the temperature of the conducting wire increases.

Total heat of steam

The amount of $BTU$ required to raise the temperature of $1\,lb$ of water from $32^{\circ}F$ to the corresponding boiling point and to change this water to saturated steam.

Celsius to Fahrenheit formula

$$Celsius = (Fahrenheit - 32) \times \frac{5}{9}$$

Conduction

The transfer of heat resulting from a difference in temperature between two objects or substances in direct physical contact.

Fahrenheit temperature scale

A temperature scale based on a $180^{\circ}$ degree separation between the melting and boiling points of water, with fixed points at $32^{\circ}$ and $212^{\circ}$.

Specific heat

A ratio of the heat capacity of a substance to the heat capacity of pure water.

Superheated

The state of a gas or vapor when it is heated to a temperature higher than its boiling point.

Evaporation

The physical process exemplified by the operation of a cooling tower.

Radiation

A method of heat transfer that does not require a medium between two objects for the transfer to take place.

Infrared thermometer

A device used for noncontact temperature measurement.

Sensible Heat

Heat that causes changes in temperature that can be measured.

Flashing

An occurrence where water, under pressure, is released from a steam boiler to the atmosphere, such as during boiler blow down operations.

Wet saturated steam

Steam that contains a moisture content of more than $2\%$.

Steam

The vapor that forms when water is heated to its boiling point at $1\,atm$ at $212^{\circ}F$.

Intensity of heat

The velocity attained by the molecules in a substance, which is indirectly measured by temperature.

Latent heat of vaporization

The type of heat involved with changes between the liquid and gas/vapor state.

Temperature

An indirect measure of the velocity attained by the molecules in a substance.

Natural convection

Heat transfer occurring because of a combination of conduction and the actual movement of some of the fluid from one place to another.

Celsius temperature scale

A temperature scale based on a $100^{\circ}$ degree separation between the freezing and boiling points of water, with fixed points at $0^{\circ}$ and $100^{\circ}$.

Latent heat

Heat that a substance continues to absorb or remove without a change in temperature until it has absorbed or removed enough heat to change state.

Thermal conductivity rating

The rating upon which the rate of heat conduction through a material is dependent.

Saturation point

A given phase containing the highest concentration of molecules of a certain substance that it can hold before it changes state.

Liquid-in-glass thermometer

A thermometer that measures temperature by the expansion or contraction of the liquid in the stem.

Thermodynamics

The science of thermal energy (heat) and how it transforms to and from other forms of energy.

Condensation

The formation of water on the outside of a glass of ice water in summer.