Photoelectric and Ultrasonic Sensors 240

acoustic

Relating to sound. Acoustic interference can cause ultrasonic sensors to malfunction.

alignment

The accurate positioning of components in relation to one another. Sensors require proper alignment to be effective.

alternating current

AC. Electricity that reverses direction at regularly recurring intervals of time. In the United States, alternating current cycles 60 times per second, or at 60 Hertz (Hz).

amplifies

The increasing of an electronic signal's strength or amplitude. Amplifying an ultrasonic sensor's signal increases the loudness of the signal.

analog

An electrical signal that continuously varies within a specific range. Analog outputs communicate information about variable conditions, such as distance or size.

anti-vibration brackets

A mounting device designed to minimize the movement of installed equipment. Anti-vibration brackets help ultrasonic sensors maintain accuracy.

beam angle

The angle of the signal emitted by a sensor. Beam angle determines the sensor's sensing and detection ranges.

binary digits

The smallest unit of information on a computer. Binary digits, also known as bits, are formed using 1s and 0s.

brackets

A mounted support device. Brackets come in different forms for sensor installation.

calibrate

To compare and adjust a device or machine with unknown accuracy to a device with a known, accurate standard. Sensors must be calibrated after installation.

ceramics

A hard, brittle material that can withstand high temperatures and resist corrosion. Some ceramics are piezoelectric.

crystals

A type of material with atoms arranged in a highly organized and repeating structure. Many crystals, such as quartz, are piezoelectric.

current

The flow of electricity through a circuit. Current strength is called amperage and is measured in amperes (A), or amps.

dark operate mode

DO mode. A photoelectric sensor operating mode in which the output turns on when light from the emitter does not reach the receiver. Dark operate mode triggers the sensor when an object blocks the light from reaching the receiver.

detection range

The entire area that a sensor can observe from a fixed position. The detection range, also known as the field of view, accounts for the signal's distance and width.

diffuse

A sensor that uses the target or background to bounce the signal sent by the emitter back to the receiver. Diffuse sensors use one-point systems because the emitter and receiver are housed in the same unit.

digital

An electrical signal that is output as a series of pulses or signals, often resulting in binary strings of 0s and 1s. Digital outputs allow sensors to turn machines on and off.

echoes

A reflection of a sound wave that returns to the source after striking a surface. Echoes are analyzed by ultrasonic sensors operating in pulse-echo mode.

electrical signals

A current that carries data from one device to another. Electrical signals are either analog or digital.

emitter

The part of a sensor that sends out a signal to a receiver. An emitter may send out sound waves or a light beam.

excess gain

The amount of additional light a sensor requires to operate properly in a contaminated environment or an environment with excess light. Excess gain must increase to account for higher levels of contamination or light interference.

false positives

An error that occurs when a sensor registers as detecting an object but no object is present or the incorrect object is present. False positives can result from choosing a sensor without the proper sensing range.

fiber optic

A bundle of thin, flexible cables made of glass or plastic that emit and receive light signals. Fiber optic cables can serve as an extension of the emitter and receiver in photoelectric sensors.

fiber optic sensors

A type of photoelectric sensor that uses fiber optic cables to carry and receive signals. Fiber optic sensors are used in high-temperature environments, restricted spaces, and contaminated environments.

field of view

The entire area that a sensor can observe from a fixed position. The field of view, also known as the detection range, accounts for the signal's distance and width.

frequency

A measurement of the number of times a waveform repeats in one second. Frequency is measured in hertz (Hz).

gain

The amount of light a sensor emits. Gain can be adjusted based on the environment of the sensor.

high-voltage lines

An electrical conductor with enough potential energy to cause serious injuries to people and serious damage to equipment. High-voltage lines can interfere with sensors when they are placed close together.

infrared light

IR light. A wavelength of light that is beyond, or longer than, red on the visible light spectrum. Infrared light is invisible to the human eye.

input

Energy received by a device. Input signals include light and sound.

input terminals

A connection point on a sensor where electricity enters the sensor. Low or absent voltage at the input terminals can indicate a faulty power supply.

input/output-link

I/O-link. A point-to-point communication system that communicates more sensor data. An input/output-link can provide data such as exact distances and signal integrity.

inspection

The examination of a part during or after its creation to confirm that it adheres to quality specifications. Inspection processes may use photoelectric and ultrasonic sensors to detect defects.

interference

An unwanted signal that impedes the functioning of an electrical device. Interference can cause a sensor to malfunction.

laser diode

A semiconductor device that generates light in laser form. Laser diodes operate similarly to light-emitting diodes, but the emitted beam is different.

laser sensors

A type of photoelectric sensor that uses a laser as the signal. Laser sensors are commonly used for safety purposes, such as in light curtains.

lens

A curved, transparent component used to concentrate or disperse light rays. Lenses on photoelectric sensors must be clean to function properly.

light curtains

A type of presence-sensing device consisting of a field of light that stops a machine when the light is blocked by an object. Light curtains prevent mechanical parts from striking employees and equipment.

light operate mode

LO mode. A photoelectric sensor operating mode in which the output turns on when light from the emitter reaches the receiver. Light operate mode triggers the sensor when there is nothing in front of it.

light-emitting diode

LED. A semiconductor device that emits a narrow spectrum of light in a forward direction. Light-emitting diodes are commonly used in photoelectric sensors.

linear

Extending in a straight or nearly straight line. A photoelectric sensor emits light in a linear beam.

load

A component in a circuit that converts electrical energy into light, heat, or mechanical motion. A load, such as a light bulb, appliance, or machine, may be controlled by a photoelectric or ultrasonic sensor.

lockout/tagout

LOTO. A method of protecting employees from accidental machine startup through proper locking and labeling of machines undergoing maintenance. Lockout/tagout renders a tool or machine inoperable.

motor control

A group of devices used to start, stop, or change the speed or direction of a motor. Motor control systems use sensors to enhance safety and automation.

multimeter

A device that can measure voltage, amperage, and resistance. A multimeter is used to verify that a device receives voltage from a power source.

non-contact sensors

A type of sensor that detects changes and objects without using physical contact. Non-contact sensors include photoelectric and ultrasonic sensors.

non-destructive testing

A category of inspection processes that evaluate a part's properties and performance using methods that do not damage or permanently alter the part. Non-destructive testing methods include visual testing, liquid penetrant testing, magnetic particle testing, eddy current testing, ultrasonic testing, and radiographic testing.

NPN sensors

A sensor that receives current and provides a path to the load. NPN sensors, also known as sinking sensors, contain a NPN transistor.

NPN transistor

A semiconductor device that consists of a layer of P-type semiconductor material sandwiched between two layers of N-type material. A NPN transistor is used in sinking sensors and has fast switching speeds.

one-point systems

A sensor that consists of a single unit. One-point systems are used by diffuse sensors.

oscilloscope

A device that displays a visual representation of a waveform. An oscilloscope can be used to test the signal produced by ultrasonic sensor's emitter.

output

Energy released by a device. Output energy is often electrical signals.

personal protective equipment

PPE. Any article of clothing or device worn or used to minimize exposure to hazards and prevent injury. Personal protective equipment may include safety glasses, safety gloves, earplugs, respirators, or steel-toed boots.

photo eyes

A type of non-contact sensor that emits and analyzes a beam of light. Photo eyes, also known as photoelectric sensors, are used in safety devices like light curtains.

photoelectric sensors

A type of non-contact sensor that emits and analyzes a beam of light. Photoelectric sensors, also known as photo eyes, are used in safety devices like light curtains.

piezoelectric

Having the ability to generate an electrical charge when subjected to mechanical stresses. Piezoelectric materials also generate mechanical forces when energized by electricity.

PNP sensors

A sensor that supplies positive voltage to a load. PNP sensors, also known as sourcing sensors, contain a PNP transistor.

PNP transistor

A semiconductor device that consists of a layer of N-type semiconductor material sandwiched between two layers of P-type material. A PNP transistor is used in sourcing sensors and is easier to troubleshoot.

power source

A device that generates electricity. Power sources include generators and batteries.

programmable logic controllers

PLCs. A processor-driven device that uses computer software to provide electrical control to machines. Programmable logic controller are often connected to sensors.

pulse-echo mode

An ultrasonic sensor operating mode that analyzes the echoes reflected by a target, reflector, or background. Pulse-echo mode is used to detect internal flaws in parts and characterize the material of targets.

quality assurance

A system of managing quality by regulating the quality of materials, assembly processes, products, and components. Quality assurance is a proactive approach to preventing errors.

quartz

A hard, crystalline mineral made of silica. Quartz is piezoelectric and often used in transducers.

radial

Extending outward from a common center point. A radial beam has a wider detection range but a shorter sensing range.

recalibrate

To reset or reconfigure a device in order to operate more accurately after initial calibration. A malfunctioning sensor must be recalibrated after any problems are fixed.

receiver

The part of a sensor that detects a signal sent by an emitter. A receiver can detect sound waves or a light beam.

reflector

A component of a retroreflective sensor that bounces the signal sent by the emitter back to the receiver. A reflector is a separate part that must be installed across from the emitter and receiver unit.

retroreflective

A sensor that uses a reflector to bounce a signal sent by the emitter back to a receiver. A retroreflective sensor's emitter and receiver are housed in the same unit.

sensing modes

The setup that determines how a sensor detects a target. Sensing modes commonly include through-beam, retroreflection, and diffuse.

sensing range

The maximum distance at which a sensor can detect a signal. The sensing range depends on many factors, such as the object being detected and the type of sensor.

sensitivity

The smallest change in an input that a sensor is capable of detecting. The sensitivity of a sensor should be adjusted if the sensor is detecting false positives or having trouble detecting an object.

sensitivity adjustment screw

A device on a sensor that is used to increase or decrease the sensor's ability to detect targets. The sensitivity adjustment screw is turned using a screwdriver.

signal

Energy that varies over time and is used to carry information. Signals include changes in electrical energy, heat, light, sound, pressure, magnetic fields, and other stimuli.

signal integrity

The ability of a signal to preserve its strength when traveling between devices. Signal integrity can be monitored with an I/O-link.

signal-to-noise ratio

The comparison of a sound wave signal to the level of interference in an environment. Signal-to-noise can be improved by increasing the signal volume or reducing acoustic environmental noise.

sinking sensors

A sensor that receives current and provides a path to the load. Sinking sensors, also known as NPN sensors, contain a NPN transistor.

smart manufacturing

A method of manufacturing designed to improve product design and processes by integrating digital technology throughout the supply chain. Smart manufacturing increases connectivity and data exchange between all areas of product development, factory operations, and enterprise systems.

sound waves

A vibration, or disturbance, of matter caused by the movement of energy. The sound waves used by ultrasonic sensors have a frequency beyond the range of normal human hearing.

sourcing sensors

A sensor that supplies positive voltage to a load. Sourcing sensors, also known as PNP sensors, contain a PNP transistor.

straight edge

A flat, rectangular hand tool that can be used to draw straight lines and determine the straightness of a line. A straight edge is used to align certain types of sensors.

targets

The physical object or substance that a sensor intends to perceive. A target may be a part or even liquid in a tank.

through-beam

Thru-beam. A sensor that sends a signal directly from an emitter to a receiver. A through-beam sensor detects an object when it passes between the emitter and receiver units.

thru-beam

Through-beam. A sensor that sends a signal directly from an emitter to a receiver. A thru-beam sensor detects an object when it passes between the emitter and receiver units.

transducers

A device that converts one form of energy to another. A transducer in an ultrasonic sensor uses the properties of a semiconductor material to convert sound waves into electrical energy to be analyzed.

troubleshooting

The systematic elimination of the various parts of a malfunctioning system, circuit, or process to locate the source of the problem. Troubleshooting an electrical circuit often involves conducting visual inspection, consulting electrical prints, and using electrical testing instruments.

two-point system

A sensor that consists of two separate units. Two-point systems are used by through-beam and retroreflective sensors.

ultrasonic sensors

A type of non-contact sensor that emits and analyzes high-frequency sound waves. Ultrasonic sensors are extremely precise and can be used with almost any type of material.

vacuum

A space with negative air pressure created by removing air with suction. Ultrasonic sensors do not work in vacuum environments.

visual inspection

An assessment of components done with the naked eye to look for defects and mechanical damage. Visual inspection of sensors may reveal broken wires or incorrect wiring.

voltage

A measure of the electrical force or pressure that causes current to flow in a circuit. Voltage is measured in volts (V).

waveform

The shape of a wave produced by a sound signal. The waveform of a sound signal depends on its amplitude and frequency.

window mode

An ultrasonic sensor operating mode that detects objects within a certain space or area. Window mode is useful for ensuring a part is the correct size or oriented correctly.

wiring diagram

An electrical print that shows the physical locations and electrical relationships of all electrical components in a circuit. The wiring diagram should be consulted before installing photoelectric and ultrasonic sensors.