Industrial Terminology Glossary – P
Panel Meter
An instrument that displays an input signal in either a digital or analog form
Parallax
The seeming displacement of an object and its background when viewed from two different points of observation. A common source of error when reading analog gauges.
Parallel Circuit
A parallel circuit is a closed circuit in which the current divides into two or more paths before recombining to complete the circuit. Each load connected in a separate path receives the full circuit voltage, and the total circuit current is equal to the sum of the individual branch currents.
Parallel Communications
A method of conveying multiple binary digits (bits) simultaneously. For example, an 8-bit parallel channel will convey eight bits (or a byte) simultaneously, whereas a serial channel would convey those same bits sequentially, one at a time.
Parity
A process that ensures accurate data transmission between nodes. A parity bit is added to the end of the original data bits to create an even or odd number.
Peak Demand (maximum RMS power)
The highest average load during a specified time interval (kW).
Peak Hold
An instrument function that permits retaining and displaying the peak value momentarily reached by a pulse or other brief signal under measurement.
pH
A figure expressing the acidity or alkalinity of a solution on a logarithmic scale on which 7 is neutral, lower values are more acid and higher values more alkaline.
A precision scientific device designed for the purpose of determining the relative acidity or alkalinity of a liquid solution, particularly those predominantly consisting of water. Read More…
Phase
In electronic signaling, phase is a definition of the position of a point in time (instant) on a waveform cycle. A complete cycle is defined as 360 degrees of phase. Phase can also be an expression of relative displacement between or among waves having the same frequency.
Phase Angle
An expression of relative displacement between or among waves having the same frequency.
A specialized tool for precisely assessing hole and slot dimensions and positions. Read More…
A calibrated glass tube used for accurately measuring and transferring specific liquid volumes. Read More…
Pivot and Jewel
Method of suspending the moving coil or moving iron vane in a magnetic field, in analog meters. The movable element is equipped with two metal pivots that engage glass or synthetic jewel cup bearings. In most designs, the bearings are spring-backed to prevent dislodging of the pivots by shock or vibration.
Platinum Resistance Thermometer (PRT)
A resistance temperature detector (RTD) that uses platinum as the metal conductor whose electrical resistance changes as a function of temperature.
Poise
A counterweight used to balance a scale
Polyphase Wattmeter
This wattmeter consists of 2 or 3 single-phase wattmeters mounted in the same package. The watt sensing elements can be electronic transducers or analog dynamometers. A dual element wattmeter will measure power in a 3 phase 3-wire system regardless of power factor, voltage or current variations between phases. Most common analog dynamometer forms are 2, 2-1/2, or 3 element types. In 4-wire circuits with the 4th wire carrying current, the 2-1/2 or 3 element types are used. If there is voltage unbalance, only the 3 element is suitable.
Port (Electronics)
A place where different devices connect in a circuit and signals can be introduced or taken away
Positive Temperature Coefficient (PTC)
A characteristic observed in specific materials, such as platinum and nickel, where their electrical resistance increases as the temperature rises. Read More…
The maximum voltage attainable from an energy source, such as a battery or generator. Read More…
Potential Transformer
An instrument transformer used to step down high voltage potentials to lower levels acceptable for the input of electrical test instruments
Potentiometer
A resistor with an adjustable voltage divider.
Potted Cell
A load cell that is protected well so it may perform in harsh environments
Pounds per Square Inch (PSI)
A unit of measure defined by the pressure created when one pound-force is applied over a surface area of one inch.
Pounds per Square Inch Absolute (PSIA)
A measurement of pressure measured relative to a vacuum rather than the atmosphere
Pounds per Square Inch Gauge (PSIG)
A measurement of pressure measured relative to the atmosphere rather than a vacuum
Power Factor
The ratio of consumed power (watts) to apparent (volt-ampere) power in an AC circuit. Expressed in decimal form.
An electrical device that transforms and dispenses electrical power from a source to a recipient. Read More…
PPM (Parts Per Million)
Just as per cent means parts of a hundred, parts per million defines parts of a million. Often used in measurement to annotate very small percentages (0.0001% = 1ppm).
The extent to which multiple measurements of a particular quantity closely align with each other. Read More…
A pressure gauge is an instrument designed to quantify the force exerted on a surface in relation to the surface’s area by a fluid. There are two primary types of pressure gauges: analog and digital. Analog pressure gauges rely on a pointer and a dial to convey pressure measurements, whereas digital pressure gauges present the pressure value in numerical format on a screen. Read More…
A pressure relief valve (PRV) plays a crucial role in ensuring the safety and integrity of hydraulic systems. Its primary purpose is to maintain the system pressure within a designated and safe range. Read More…
A device designed to transform physical pressure into an electrical signal. It functions as a sensor primarily used for measuring the pressure of both liquids and gases. Read More…
A device engineered to precisely assess the pressure levels within a fluid, liquid, or gas. Read More…
Pressurization
The act of increasing the pressure in an enclosure above the atmospheric pressure outside the enclosure.
Primary Axis
The imaginary line that the load should be placed on. Usually runs through the center of the load cell
Process Calibrator
A single device containing a variety of instruments used for calibrating process instruments such as pressure gauges or transducers and thermocouple or RTD temperature controllers.
Process Meter
Any of a variety of instruments designed to measure, display, alarm, and control a wide range of process variables, such as 4-20 mA and 0-10 V analog inputs.
Protection Device
Device installed with the aims of protection of assets and ensuring continued supply of energy. Switchgear is a combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment.
Pneumatic Torque Tool
A planetary torque multiplier or a gearbox that is mated to a pneumatic air motor. At the end of the gearbox is a reaction device that absorbs torque to ensure proper torque at the joint.
Pulse Torque Tool
Rotary torque tools which apply torque in increments rather than in one continuous effort. This type of torque application is also known as discontinuous drive.
Purging
Supplying a steady flow of clean air into a closed area to get rid of any flammable or hazardous gas.
Push-Button Auto Zero (PAZ)
A button that when pushed balances the scale to display 0 even if something is on it.def
