|


Immiscible -- incapable of being mixed without separation of phases. Water
and petroleum oil are immiscible under most conditions, although they can be
made miscible with the addition of an emulsifier.
In-line filter -- a filter assembly in which the inlet, outlet and filter element
axes are in a straight line.
Indicator, pressure -- an indicator that signals pressure conditions.
Indicator, differential pressure -- an indicator which signals the difference
in pressure between two points, typically between the upstream and downstream
sides of a filter element.
Influent -- the fluid entering a component.
Infrared spectroscopy -- an analytical method using infrared absorption for
assessing the properties of used oil and certain contaminants suspended therein.
See FTIR.
Infrared spectra -- a graph of infrared energy absorbed at various frequencies
in the additive region of the infrared spectrum. The current sample, the reference
oil and the previous samples are usually compared.
Ingested contaminants -- environmental contaminant that ingresses due to the
action of the system or machine.
Ingression level -- particles added per unit of circulating fluid volume.
Inhibitor -- any substance that slows or prevents such chemical reactions as
corrosion or oxidation.
Inorganic compound -- a chemical compound usually mineral that does not include
hydrocarbons or their derivatives. Some simple carbon compounds such as carbon dioxide and carbon
disulphide are regarded as inorganic.
Insolubles -- particles of carbon or agglomerates of carbon and other material.
Indicates deposition or dispersant drop-out in an engine. Not serious in a compressor
or gearbox unless there has been a rapid increase in these particles.
Insulating oil -- high quality oil with superior oxidation stability and dielectric strength as a coolant for transformers and other electrical equipment.
Intensifier -- a device which converts low pressure fluid power into higher
pressure fluid power.
Interfacial tension (IFT) -- the energy per unit area present at the boundary
of two immiscible liquids. It is usually expressed in dynes/cm (ASTM Designation
D 971.)
IP -- Institute of Petroleum
Iron (Fe) -- element number 26 on the periodic table of the elements.
In the context of oil analysis iron can be present as a wear metal in various sampled components
and the origins can be from such sources as: gears, bearings, and shafts just to name a few.
ISO -- International Organization for Standardization
ISO Solid Contaminant Code (ISO 4406) -- a code assigned on the basis of the
number of particles per unit volume greater than 5 and 15 micrometers in size.
Range numbers identify each increment in the particle population throughout
the spectrum of levels.
ISO Standard 4021 -- the accepted procedure for extracting samples from dynamic
fluid lines.
ISO viscosity grade -- a number indicating the nominal viscosity of an industrial
fluid lubricant at 40°C (104°F) as defined by ASTM Standard Viscosity
System for Industrial Fluid Lubricants D 2422. Essentially identical to ISO
Standard 3448.
Journal -- that part of a shaft or axle that rotates or angularly oscillates
in or against a bearing or about which a bearing rotates or angularly oscillates.
Journal bearing -- a sliding type of bearing having either rotating or oscillatory
motion and in conjunction with which a journal operates. In a full or sleeve
type journal bearing, the bearing surface is 360° in extent. In a partial
bearing, the bearing surface is less than 360° in extent, i.e., 150°,
120°, etc.
|