motor control 2-3
What is the photoelectric scanning method in which the transmitter and receiver are housed in the same enclosure and in which a specialized scanning technique is used not only to determine when an object is moved into position but also to identify the specific location of the object?
Diffuse
What is the photoelectric scanning method in which the transmitter and receiver are placed opposite each other?
Direct
? devices are solid-state sensors that detect the presence of a magnetic field.
Hall effect
? proximity sensors can only detect metals that conduct current
Inductive
? devices are non-contact solid-state devices that use light to detect the presence of objects.
Photoelectric
What is the photoelectric scanning method in which the receiver responds only to the depolarized reflected light from a special reflector or polarized sensitive reflective tape?
Polarized
Electronic sensors with a(n) ? output interface can switch AC or DC without the specific polarity requirements for DC circuits.
Relay
? is measured by the number of light pulses per second that a photoelectric device transmits.
Response time
What is the photoelectric scanning method in which the transmitter and receiver are housed in the same enclosure and the transmitted beam is reflected back to the receiver from a reflector?
Retroreflective
? is the threshold value for received light to trigger a change in the output status of a photoelectric device.
Sensitivity
A primary step in troubleshooting any of the sensors covered is to determine if the sensor has the correct operating input voltage.
True
Discrete mechanical sensors have contacts that open and close. Since discrete electronic sensors often do not have mechanical contacts, the output condition is described as activated or de-activated.
True
Since solid-state sensors use semiconductor circuits instead of contacts to switch the attached load, the load must match the voltage and current specifications for the sensor.
True
The output signal of a discrete sensor can only be on or off.
True
What type of proximity sensor emits a high frequency sound signal and detects the reflected sound from the object?
Ultrasonic
A photocell is a photoelectric device that only reacts to ? light.
ambient
A(n) ? proximity sensor can detect a wide range of materials, including metals (ferrous and nonferrous), glass, plastics, and liquids.
capacitive
Proximity sensors that detect objects using an electrostatic field are known as ? devices.
capacitive
The size and dielectric properties of the object are the two factors that determine the effective sensing range of a ? proximity sensor.
capacitive
A ? operating margin indicates that a sensor will be reliable when ambient light conditions are variable.
higher
Proximity sensors that detect objects using an electromagnetic field are known as ? devices.
inductive
The size of the object and the type of metal (ferrous or nonferrous) are two factors that determine the effective sensing range of a(n) ? proximity sensor.
inductive
The ? modes enable a photoelectric sensor to detect whether a target is present or absent.
light/dark operation
Identify the NEMA symbol with the correct 3-wire sensor.
nc PNP, NO NPN
Current-sinking outputs use the ? side of the DC output circuit as the switch leg to the load device.
negative
The ratio of the available level of light at a photoelectric sensor's receiver to the minimum level of light required to trigger the sensor is the ? .
operating margin
Response time, sensitivity, operation margin, and light/dark operation are four parameters that are commonly used to describe the operation of ? devices.
photoelectric
Current-sourcing outputs use the ? side of the DC output circuit as the switch leg to the load device.
positive
Capacitive, inductive and ultrasonic are three types of ? sensors that are based on the sensor's operating principles.
proximity
The component present in a photoelectric device that detects the presence of the light source is a ? .
receiver
Sensors that use an NPN transistor to switch DC loads are current- ? devices.
sinking
The sensor in an IEC Standard NPN device must be connected to provide a ? connection to the load.
sinking
Sensors that use a PNP transistor to switch DC loads are current- ? devices.
sourcing
The IEC Standard PNP device must be connected to provide a ? connection to the load.
sourcing
The component present in a photoelectric device that provides a light source is a ? .
transmitter