(Wireless) Antenna type whose overall span is one half the length of the wave that can be transmitted.

Light source using gas such as iodine placed inside an incandescent lamp to gather the evaporated filament off the bulb and redeposit it back onto the filament.

(Machine Safety) A hand-operated mechanism or device used as an actuating control. Two normally open “input switches” are used as hand controls in a two-hand control system.

(Machine Safety) Screens, bars, or other mechanical barriers affixed to the frame of the machine intended to prevent entry by personnel into the hazardous area(s) of a machine.

Electronic integrated circuits, boards and systems. All the machines and physical equipment directly involved in the performance of data-processing or communications functions.

(Machine Safety) Physical injury or damage to the health of people, which may result through direct interaction with the machine or through indirect means, as a result of damage to property or to the environment.

(Machine Safety) The effort to eliminate differences in the technical content of standards having the same scope, especially differences that may impact trade between countries.

(Machine Safety) A potential source of harm.

(Machine Safety) The closest reachable point of the hazardous area.

(Machine Safety) An area that poses an immediate or impending physical hazard.

(Machine Safety) A circumstance in which a person is exposed to a hazard, or any specific activity done on or around the machine during its lifecycle that results in a potential source of harm. Also known as a Task/Hazard Pair or Combination. See B11.TR3 for further information.

An air-tight seal. In photoelectrics, the lens assemblies of some sensors have hermetic seals to exclude the entrance of air and water behind the lens, thereby preventing fogging of the inner surface of the lens.

Abbreviation for Human Machine Interface. An interface that allows a user to interact with a machine or device.

(Wireless) 1. The act of changing from one frequency to another.
2. The device to device transmission link, such as from the Master device to the Slave device.

(Wireless) Precalculated, pseudorandom frequencies used by both the Transmitter and Receiver of a radio to create a hopping sequence.

Describes several aspects of a sensor: body style, housing material, and sealing capacity.

Used synonymously with the term "color" but does not include gray. It is the dominant wavelength of light, the one that distinguishes a color as red, yellow, blue, etc.

The side of a right triangle opposite the right angle.

Intentional time lag added to a circuit to prevent false actuation or intermittent operation (chatter).

Hertz. The international unit of frequency, equal to one cycle per second. Named after the German physicist, Heinrich Rudolph Hertz.