Glossary “heated air system” Definition:
Term used for heated air-intake system.
h
heated exhaust gas oxygen sensor (HEGOS)
Glossary “heated exhaust gas oxygen sensor (HEGOS)” Definition:
An oxygen sensor that is heated electronically and by engine exhaust so it warms up to normal operating temperature more quickly, allowing the engine to enter closed-loop operation sooner than with a non-heated sensor.
heat sink
Glossary “heat sink” Definition:
1). A finned, aluminum housing that dissipates heat and serves as a base on which electrical components, such as semiconductor devices, are mounted. 2). A heat dissipating section of the alternator that holds the insulated diodes or all the diodes, and carries heat away from the devices.
heat sink compound
Glossary “heat sink compound” Definition:
A paste that can be applied to parts during welding to absorb heat and prevent warpage.
heat tab
Glossary “heat tab” Definition:
A small aluminum disk attached to the cylinder head or block having a lead center designed to melt at 260¡ãF, to indicate if the engine has been overheated.
heat transfer
Glossary “heat transfer” Definition:
Movement of heat from a hotter to a colder area by conduction, convection, or radiation.
heat treatable
Glossary “heat treatable” Definition:
Metal alloy that can be hardened by heat treatment after being shaped.
heat shrink tubing
Glossary “heat shrink tubing” Definition:
Tubing that shrinks to seal electrical joints when heated.
heat riser
Glossary “heat riser” Definition:
A channel in an intake manifold through which exhaust gas flows in order to heat the manifold, thus aiding in fuel vaporization.
heat riser valve
Glossary “heat riser valve” Definition:
Control valve between the exhaust manifold and exhaust pipe that restricts the flow of exhaust, causing it to flow back through the heat-riser channel under the intake manifold. It acts as an aid to fuel evaporation and to speed engine warm-up.
heat setting
Glossary “heat setting” Definition:
Determines the length of the arc when MIG welding.
heat load
Glossary “heat load” Definition:
The “load” imposed on an A/C system. due to ambient temperature, humidity, and all other factors that produce unwanted heat.
heat of compression
Glossary “heat of compression” Definition:
An increase of temperature brought by the compression of gas, air, or an air/fuel mixture.
heat of fusion
Glossary “heat of fusion” Definition:
Amount of latent heat, in Btu, required to cause a change of state from a solid to a liquid.
heat quantity
Glossary “heat quantity” Definition:
1). Amount of heat as measured on a thermometer. 2). Amount of heat contained in an object measured in Btu’s or calories.
heat radiation
Glossary “heat radiation” Definition:
Transmission of heat from one substance to another while passing through, but not heating, intervening substances.
heat range
Glossary “heat range” Definition:
Measurement of a spark plug’s ability to transfer heat from the tip of the insulator into the cylinder head.
heat exchanger
Glossary “heat exchanger” Definition:
Apparatus in which heat is transferred from one medium to another on the principle that heat moves to an object with less heat.
heat induced ignition
Glossary “heat induced ignition” Definition:
See preignition.
heat intensity
Glossary “heat intensity” Definition:
Measurement of heat concentration with a thermometer.