Glossary “Hg” Definition:
Mercury
h
HHV
Glossary “HHV” Definition:
Higher Heating Value.
hi test
Glossary “hi test” Definition:
Gasoline that has an octane number near 90-95.
HIC
Glossary “HIC” Definition:
Hot Idle Compensator
HFC-134a
Glossary “HFC-134a” Definition:
Hydrofluorocarbon gas that is not damaging to the environment and ozone layer, and that can be used in automotive A/C systems and to replace CFC-12.
HFCF
Glossary “HFCF” Definition:
High Fan Control Fault Displayed as Yes/No.
HFCM
Glossary “HFCM” Definition:
Horizontal Fuel Conditioning Module (diesel)
hex nut
Glossary “hex nut” Definition:
Nut used when the bolt penetrates the clamping surface. The hex nut and the bolt must be the same grade and have the same thread pattern. Using nuts and bolts of different grades will not allow for proper clamping force to be developed.
hexadecimal
Glossary “hexadecimal” Definition:
The base 16 numbering system in which binary numbers are arranged in groups of four bits each. They are 0,1,2,3,4,5,6,7,8,9, and A, B, C, D, E, and F.
HFC
Glossary “HFC” Definition:
High Fan Control, or Hydrofluorocarbon
herringbone gear
Glossary “herringbone gear” Definition:
A pair of helical gears designed to operate together. The angle of the pair of gears forms a V.
heptane
Glossary “heptane” Definition:
Hydrocarbon that serves as a primary reference fuel, when determining octane ratings, with an index of 0.
hertz
Glossary “hertz” Definition:
Unit of frequency of any regularly occurring event..
Hertz Cycle
Glossary “Hertz Cycle” Definition:
Named for Heinrich Rudolf Hertz (1857 – 1894 ) The number of electrical events per second.
hesitation
Glossary “hesitation” Definition:
Momentary lack of throttle response or pause in the rate of acceleration.
HEPA filter
Glossary “HEPA filter” Definition:
A high-efficiency particulate air filter. A type of air filter that traps at least 99.7% of all particles that are 0.3 microns or larger in size.
HEPA vacuum
Glossary “HEPA vacuum” Definition:
Vacuum cleaner with a special filter that is only used for asbestos.
henry
Glossary “henry” Definition:
A unit of inductance. The inductance of a coil of wire in henries is a function of the coils size, the number of turns of wire and the type of core material used.
HEPA
Glossary “HEPA” Definition:
High Efficiency Particulate Air filter.
hemi head
Glossary “hemi head” Definition:
Cylinder head with hemispherical combustion chambers providing room for extra large valves or multi-valve arrangements and providing an ideal shape for smooth, even combustion.