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Photon

A single quantum of light energy that moves as a unit at the speed of light.

Phototransistor

A bipolar transistor that has gain and produces collector current when light shines on its collector-base junction.

Photovoltaic Diode

A device having a junction of two dissimilar metals that produces an electrical signal proportional to the amount of light that strikes it.

Physical Hazards

Any personal hazards, such as excessive noise, temperature, pressure, and rotating equipment.

Physical Properties

Properties that pertain tot he physics of a material, such as melting point, density, electrical and thermal conductivity, specific heat, and coefficient of thermal expansion.

Pi

The mathematical constant which is equal to the ratio of the circumference of a circle to its diameter. Approximately 3.1415927.

Pickup

1. Vehicle acceleration. 2. A term used for pickup truck.

Pickup Coil

An engine-speed sensor in an electronic engine system.

Pickup Truck

A type of vehicle having an open cargo bed behind an enclosed cab.

Pickup Tube

1. A tube extending from the outlet of the receiver almost to the bottom of the tank to ensure that 100% liquid is supplied to the liquid line or metering device. 2. A tube used to transfer fuel or oil from the storage tank.

Pico

The prefix representing the number. 0.000,000,000,001.

PID

An acronym for Parameter Identification Data; The opperating parameters of a sensor or device.

Piece Work

A method of payment whereby a worker receives an agreed fixed amount per piece produced.

Piezoelectric

A crystal property which causes a voltage to be developed across the crystal when mechanical stress is applied.

Piezoelectricity

Voltage produced by the application of pressure or vibration to certain crystals.

Piezoresistive

A sensor whose resistance varies in relation to pressure or force applied to it. A piezoresistive sensor receives a constant reference voltage and returns a variable signal in relation to its varying resistance.

Piezoresistive Sensor

A sensor (knock) that is sensitive to pressure changes or viborations.

Pig

1. An unattractive vehicle. 2. A vehicle that is not performing well or as expected. 3. A bar of cast metal.

Pig Tale

[1] A wiring component such as a bulb socker that is provided with wires attached for connecting to the original vehicle wiring. [2] A wiring repair connection some times refereed to as a western union pig tale splice.

Pigment

Small particles added to the paint to influence properties such as color, corrosion resistance, and mechanical strength.