Analog to Digital Converter. An electronic device that converts varying sinusoidal signals from instruments into binary code for a computer.

A flow of electricity which reaches maximum in one direction, decreases to zero, then reverses itself and reaches maximum in the opposite direction. The cycle is repeated continuously. The number of such cycles per second is frequency. The average value of voltage during any cycle is zero.

AC-coupled amplifiers may sometimes be used reliably in close differential sensing applications, since they amplify only quick signal changes and ignore slow signal changes. As a result, very small changes in light level can be highly amplified. The output of ac-coupled amplifiers is a one-shot pulse. Because ac-coupled amplifiers are sensitive to very small signal changes, they may respond to unwanted conditions like sensor vibration or electrical "noise". Use of ac-coupled amplifiers should be avoided, except when they are the only solution to a close differential sensing situation.

Equipment that will operate on either an AC or DC power source.

The rate of change of velocity, with respect to time.

The angle at which the core of the fiber will take in light.

(Machine Safety) A type of perimeter guarding, typically used to guard doorways, cell entries or exits, walkways, and machine access points. Two general characteristics of access guarding using multiple or singe beam safety systems are short range, typically 10-30 feet, and the frequent use of muting.

1. The degree to which a measured value is similar to an actual value. 2. The extent to which vision sensors can correctly measure and obtain a true value of a feature. A combination of imager resolution, pixel resolution and field of view is used to describe the match level of an inspection.

(Measurement and Inspection) The difference between indicated value and actual value, at room temperature. In most cases, the accuracy is comprised of two main sources of error: the resolution and the linearity.

(Vision Sensing) The manner in which outside information is brought into an analysis system; an image acquisition generally involves A/D conversion.

(Machine Safety) A device whose sensing function is performed by opto-electronic emitting and receiving elements detecting the interruption of optical radiations generated, within the device, by an opaque object present in the specified detection zone. Also know as Optical [Safety] Systems, Electro-optical Presence-sensing Safeguarding Devices.

To put into motion or action; to activate

(Machine Safety) A guard that can be adjusted to accommodate various jobs or set-ups.

Adjustable-field sensors use two receivers and a comparator circuit to cancel sensing response whenever the intensity of the reflected light reaching the long-range receiver exceeds the intensity of the reflected light reaching the close-range receiver. As a result, any object lying beyond the sensor's "cutoff point" can be reliably ignored.

Adjustable field sensors use an array of multiple receiver elements, which allows the sensor circuitry to move the location of the cutoff point, using a simple adjustment. Here is a downloadable reference about sensing modes.

A set of well-defined rules or procedures for solving a problem in a finite number of steps, or providing an output from a specific set of inputs. Usually implemented as a computer program.

Positioning of a sensor so that the maximum amount of the emitted energy reaches the receiver sensing element.

An exclusive Banner built-in feature that permits optimum alignment and continuous monitoring of a photoelectric sensing system. The AID system lights an indicator LED whenever the receiver "sees" its modulated light source. As alignment is improved, the pulse rate increases, indicating increased excess gain. Optimum sensor alignment is indicated by the fastest pulse rate.

Light in the area of the photoelectric sensor, not originating from the sensor emitter. Ambient light can adversely affect non-modulated sensors.

Usually refers to the air temperature at a sensing location.

(Amp) A unit of measurement of electric current. One volt across one ohm of resistance causes a current flow of one ampere. One ampere is equal to 6.28 x 1018 electrons passing a point in one second.

Strength of a signal voltage or current.

Pertaining to a class of devices or circuits in which the output varies as a continuous function of the input.

A sensor output that varies over a range of voltage (or current) and is proportional to some sensing parameter (as opposed to a digital output). The output of an analog photoelectric sensor is proportional to the strength of the received light signal. The output of an analog ultrasonic proximity sensor is proportional to the distance from the sensor to the object returning the sound echo.

(Vision Sensing) Tool set included in vision software which uses information analyzed by the Vision Tools to create distance, size and count measurements and result tolerances for the vision tools.

A logic function in which all of two or more defined input conditions must exist simultaneously before a load is energized (A and B and C = output).

The included angle of the area of response of a photoelectric sensor.

The angle at which light strikes a surface.

1) The angle formed between two lines drawn from the most widely separated points in the object plane to the center of the lens. 2) The angle between the axis of observation and perpendicular to the specimen surface.

(Machine Safety) The installation of a single emitter/receiver pair to create a sensing field that is not vertical but is greater than 30° from horizontal. Gains advantages of both area guarding and point-of-operation guarding techniques.

A positive electrode of a device.

(Machine Safety) Acronym for the American National Standards Institute, an association of industry representatives that develops technical standards (including safety standards). These standards comprise a consensus from a variety of industries on good practice and design. ANSI standards relevant to application of safety products include the ANSI B11 Series, and ANSI/RIA R15.06.

(Wireless) An electronic component used to transmit and receive radio waves. Antennas are designed to operate in a narrow frequency range.

(Wireless) A perceived increase in signal strength related to how a specific antenna can focus signal power. Antenna gain establishes the radiation pattern and signal range.

A lens attachment consisting of a pair of polarizing filters that are oriented so that planes of polarization are at 90 degrees to one another. Used to enable a photoelectric receiver to "see" only light of the desired polarization (from its modulated emitter), while blocking unwanted light. Used with retroreflective sensors for minimizing “proxing" effects from shiny objects.

(Machine Safety) A feature of a two-hand control where both hand controls must be released before the machine can restart. This is to ensure that one of the two hand control actuator is not "tied down." It is also part of the fault detection of the two-hand control system. If a mechanical button physically sticks, or if the return spring breaks, the next machine cycle will be prevented.

(Machine Safety) The function of the control system designed to limit the machine to a single stroke or cycle even if the tripping or actuating means is held operated.

1. The size of a lens opening. 2. A mechanical part attached to a lens used to restrict the size of a lens opening.

The specific use to which a sensor is put.

A prolonged electrical discharge between two electrodes.

Overall design or structure of a system or network, including all hardware and software.

(Machine Safety) A safeguarding technique that provides a means of continually sensing or detecting an individual within an area adjacent to or associated with a hazard. Often used as supplemental safeguarding to prevent start or restart of a hazard while the primary safety device is responsible for stopping or removing the hazard.

(Vision Sensing) An area light provides even illumination in a concentrated area. Well-placed area or spot lights can create shadows and glare, allowing the vision sensor to detect the presence or absence of a feature. Learn more about area lights here.

(Machine Safety) A safeguarding device that creates a sensing area or plane to detect the presence of an individual or object. Also known as an Area Scanner or Active Opto-electronic Protective Device responsive to Diffuse Reflection (AOPDDR).

1. An artificial structure, form or shape, created by accident or on purpose.
2. Distortion caused by a limitation or malfunction in graphics or sound hardware or software. Can also result from compression.

Acronym of American Standard Code for Information Interchange. Pronounced askee. An 8 bit coded character set used to represent alphanumeric, punctuation marks and certain special control characters.

Acronym for Application Specific Integrated Circuit. Pronounced a-sick. A chip designed for a specific application rather than a general-purpose chip such as a microprocessor.

(Vision Sensing) The width to height of an object. The ratio states the relationship of one side to the other. A computer monitor is 4:3, meaning 4 units wide by 3 units high.

(Wireless) Describes serial communication that does not use a receive and transmit synchronizing clock signal to transmit data.

Lessening or loss of signal intensity as the signal propagates through a medium. Attenuation is directly proportionate to frequency.

(Machine Safety) A safety light screen system feature that enables the system to be powered up into the RUN mode (or recover from a power interruption) without requiring a manual reset.

(Machine Safety) A barrier, signal, light or signage that warns individuals of an approaching, present, or the proximity of a hazard.