Saturday, 20 April 2024, 5:59 AM
Site: IMI eLearning
Course: IMI eLearning (IMI eLearning)
Glossary: Automotive Glossary
P

Pickling

The use of a chemical solution (usually acidic) to prepare a surface for painting or bonding by dissolving away surface oxides and other impurities.

PID

Parameter ID

Piezo-resistive

A special crystal that changes resistance as pressure is applied.

Piezoelectric

Voltage produced by shock waves on a piezo crystal. Used in engine knock sensors.

Pigment

Small particles added to paint to influence properties such as colour, corrosion resistance, mechanical strength, etc. Pigments may be coloured, semi-transparent, black, white, or colourless. They must be incorporated into a paint system by very efficient dispersion processes.

Pilot Bearing

Small bearing usually where two shafts meet. See also Spigot.

Pinging

Noise heard from an engine when the ignition of fuel occurs too early (advanced) in the cycle. Also 'ping'.

Pinholing

A defect consisting of tiny holes in the dried paint surface. Defects such as pin holing, popping, bubbling, and cratering are usually caused by solvent vapours forming from the substrate or the paint and rising to the surface.

Pinion

A small gear wheel or the driver of a meshing pair of gear wheels.

Pinion Gear

A small gear wheel or the driver of a meshing pair of gear wheels.