Dither is expressed by the dither frequency (Hz) and the peak-to-peak dither current amplitude.

Absolute viscosity divided by fluid density equals kinematic viscosity.

Interference between opposing asperities in sliding or rolling applications is a source of friction, and can lead to metal welding and scoring.

Ideally, the lubricating film between two moving surfaces should be thicker than the combined height of the opposing asperities.

It is a measure of the particle-capture efficiency of a filter element.

The ISO 4572 Multipass Test Procedure passes fluid through a test circuit to check for contaminant retention.

A measured amount of contaminant is injected upstream of the filter and laser particle counters record particles in to particles out across the filter.

When 100,000 particles are measured upstream of a 10( filter and 10,000 downstream it would have a Beta Ratio of 10.

B10(100,00010,00010).

Efficiency of a filter element is what counts when comparing one filter to another.

Efficiency coupled with the volume of contaminant retention can make a more expensive filter cost less due to its longer useful life.

Boundary lubrication can be made more effective by including additives in the lubricating oil that provide a stronger oil film, thus preventing excessive friction and possible scoring.

There are varying degrees of boundary lubrication, depending on the severity of service.

An excessive breakout value indicates the development of adhesion.

Also, the pitting or wearing away of a solid surface as a result of low fluid levels that draw air into the system.

Compression efficiency accounts for fluid-friction losses, leakage, and thermodynamic variations from the theoretical process.

Polar compounds wet the metal surface preferentially, protecting it with a film of oil.

Other compounds may absorb water by incorporating it in a water-in-oil emulsion so that only the oil touches the metal surface.

Another type of corrosion inhibitor combines chemically with the metal to present a non-reactive surface.

This relaxation eventually results in permanent deformation or set.

It usually consists of a movable element such as a piston and piston rod, plunger or ram, operating within a cylindrical bore.

For double-acting cylinders, the value must be given for both directions of stroke.

For practical purposes, it must be referred to a stated pressure.

This term applies only to positive-displacement compressors.

Symbol For Diaphragm Pump