PH

1. Measurement of the free hydrogen ion concentration in an aqueous solution. A pH of 7 is neutral. Acid substances have lower pH. Basic substances have higher pH.
2. Mathematically, pH is the logarithm (base 10) of the reciprocal of the hydrogen ion concentration. The pH may range from 0 to 14, where 0 is most acidic, 14 most basic, and 7 is neutral. Natural waters usually have a pH between 6.5 and 8.5.

Also see

• PH value

Phaeton

An open-type body with two cross seats, it usually accommodates five passengers. A folding Windshield, folding weatherproof fabric top and removable side curtains are usually standard equipment. The four-seater was called a double phaeton, and the six-seater or seven-seater was called a triple phaeton.

Also see

• Sport and Imperial phaeton

Phase

1. Distinct functional operation during a cycle.
2. The space relationship of windings and changing values of the recurring cycles of AC

Phase Control

See

• Automatic Phase Control

Phase displacement

The mechanical and electrical angle by which phases in a polyphase motor or main and capacitor (or starting) windings in an induction motor are displaced from one another

Phase Electrical

See

• Single Phase Electrical
• Three Phase Electrical

Phase-locked loop circuitry

See

• PLL circuitry

Phase loss monitor

Motor protection device for polyphase motors that measures current flow to detect phase loss.

Phase pressure forming

See

• Solid phase pressure forming

Phase Separation

The phenomenon of a separation of a liquid or vapor into two or more physically distinct and mechanically separable portions or layers.

Phase Shift Keying

See

• Binary Phase Shift Keying
• Quaternary Phaseshift Keying

Phenol

An organic compound that is an alcohol derivative of Benzene.

Phenolic

A wheel cylinder or caliper piston made of plastic (phenolic) material rather than metal.

Phenolic spacer

A carburetor base gasket made from a thermosetting resin used specifically for heat insulation between the carburetor and the intake manifold

Phenomena

The basis of symptoms

Phial

Term sometimes used to denote the sensing element on a thermostatic expansion valve.

Phillips head screw

A screw having a fairly deep cross slot instead of the single slot as used in conventional screws.

Phillips Recessed Head

A type of screw drive having a cross recess with a wide center opening, steep walls and a blunt conical bottom. Permits easy and rapid entrance of the 4-winged driver.

Phillips screw

A common type of cross-head screw

Phillips screwdriver

Phillips Screwdriver Tip

A Screwdriver with a blunted pointed tip that is shaped to fit the crossed slots in the heads of Phillips screws. It is distinguished from a Reed and Prince screwdriver which has a pointed tip.

Phone

See

• Car phone
• Cellular phone
• Mobile phone

Phosphate

See

• Manganese phosphate coating

Phosphate coating

A special conversion coating produced by phosphating. It is applied to camshafts which promotes oil retention.

Also see

• Manganese phosphate coating
• Zinc phosphate coating

Phosphate section

A section in a painting line in which Phosphate treatment is performed

Phosphate treatment

A treatment of metals with a phosphating solution to produce a phosphate conversion coating on the surface

Phosphating

See

• Heavy phosphating
• Low temperature phosphating
• Phosphate treatment

Phosphating solution

A solution of phosphoric acid, often enriched with zinc, used during the bodywork production process for cleaning and rust prevention

Phosphor-bronze

Bearing material composed of tin, Lead, and copper.

Phosphoric acid fuel cell

(PAFC) A type of fuel cell in which the electrolyte consists of concentrated phosphoric acid (H3PO4) and protons (H+) are transported from the anode to the cathode. The operating temperature range is generally 160 - 220°C.

Phosphorus

A non-metallic substance that lowers the rate of oxidation, thereby helping resist corrosion.

Photocell

See

• Cadmium Photocell

Photochemical

Relates to branch of chemistry where radiant energy (sunlight) produces various chemical changes.

Photodiode

A light-emitting or light-sensitive diode commonly used in sensing or switching circuits.

Photoelectricity

Physical action wherein an electrical flow is generated by light waves.

Photon

Particle of electromagnetic energy found in solar radiation.

Photostatically

Method by which the molecular formation of an element changes due to light.

Photosynthesis

The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll, with sunlight as the energy source. Carbon is sequestered and oxygen and water vapor are released in the process. While plants can handle carbon dioxide in a beneficial way, they cannot process carbon monoxide as emitted from vehicle exhausts.

Photovoltaic cell

(PVC) An electronic device consisting of layers of semiconductor materials fabricated to form a junction (adjacent layers of materials with different electronic characteristics) and electrical contacts and being capable of converting incident light directly into electricity (direct current).

Also see

• Solar cell

Photovoltaic module

An integrated assembly of interconnected photovoltaic cells designed to deliver a selected level of working voltage and current at its output terminals, packaged for protection against environmental degradation, and suited for incorporation in photovoltaic power systems.

PH value

A measure of the concentration of hydrogen ions in a solution, which shows the strength of acid or alkaline. The pH value of an aqueous solution is a number describing its acidity or alkalinity. The pH of a neutral solution is 7.0 at 25°C

Physical Properties

The characteristics of a substance which distinguishes it from another substance, such as color, density, electrical conductivity, magnetism, co-efficient of thermal expansion, etc.

☜ ☞