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WorksheetsMEC5
Total questions: 39
Worksheet time: 1hrs 2mins
(a) are signal converters, which converts a physical variable (temp., position, pressure, etc.) into a different, more easily evaluated variable (usually an electrical signal)
Sensors provide sensing and measurement of the process and variable in manufacturing; they are always the first device in the whole automation system; they provide feedback in closed-loop systems.
True
False
Sensors which detect movement by means of contactless sensing (magnetic, optical, inductive or capacitive)
(a)
These converts physical quantity into a continuous analogue signal in which signal’s amplitude (current, voltage, resistance) or frequency or pulse width (PWM) tells the extent of the physical quantity being measured.
(a)
These converts physical quantity into a continuous analogue signal in which signal’s amplitude (current, voltage, resistance) or frequency or pulse width (PWM) tells the extent of the physical quantity being measured.
(a)
In a 2-wire DC/AC Technology the load is connected in series with the sensor and the supply.
True
False
Possess antivalent switching function (possess both NO and NC in just one device)
(a)
Magnetic Field Lines always run from the north pole to the south pole; Both poles never occur individually.
True
False
(a) are magnetized by applying strong magnetic field to them so as to retain the magnetic field in them
(a) are temporarily magnetized by applying current to its conducting wire; an iron core is placed to further intensify or align the generated magnetic field
The most simple way to detect a magnetic material with on/off output.
(a)
(a) sensors often consist of semi-conductive materials such as indium- antimonide (InSb) or indium-antimonide/nickel-antimonide (InSb-NiSb), which change their electrical resistance in the presence of a magnetic field.
(a) proximity sensors emits high frequency alternating electromagnetic fields which will be evaluated by its oscillator circuitry.
In an inductive sensor the switching distance depends on the (a) of the material to be detected
(a) proximity sensors emits high frequency alternating electric fields which will be evaluated by its oscillator circuitry.
The active element of a capacitive proximity sensor consists of a (a) , which is made up of a disc-shaped metallic electrode and a beaker-shaped half-open metallic shield
Depending on the composition of its semiconductor material, light beams of varying wavelengths (or color) are emitted
True
False
(a) or light-emitting diodes (LED) are used as emitters in optical proximity sensors; they emit light beams when an electrical current passes through
Photodiodes or (a) are used as receivers in optical proximity sensors; they generate electrical charges when exposed to light emission (photoelectric effect)
The smaller the wavelength of the light beam (higher frequency), the higher is its signal attenuation as it propagates through fiber optic cables and harder to receive
True
False
(a) is used in optical proximity sensors because of their reduced light attenuation (longer wavelength)
Infrared light beam is used in optical proximity sensors because they are susceptible to ambient light interferences and they can span greater distances than red light beams
True
False
In (a) sensors, emitter and receiver are separately assembled whereby wide sensing ranges can be achieved
In (a) sensors, emitter and receiver are installed in one single housing; additional reflector material is required
In (a) sensors, emitter and receiver are installed in one single housing; no reflector is needed
(a) proximity sensors is a diffused-scanning sensor that emits acoustic sound waves in the non-audible range (ultrasonic) and senses object presence via the diffused reflection of the acoustic waves
The minimum object size required for proper sensing of an ultrasonic sensor depends on the sensor beam’s (a)
Sensors which converts physical variable are called (a) (passive device) or electronic sensors (active device).
Types of Sensors According to Output (5)
Sensors with analogue output without integrated amplifier and conversion circuit
Output are in millivolts or milliamps range and needs to be evaluated by additional circuitry
(a)
Fields of Application of Proximity Position Sensors (6)
Types of Connections of Sensor (4)
Important Criteria in Selecting Sensors (6)
Magnetic Proximity Sensor: Ways to Detect Magnet (5)
Disadvantages of through-beam sensing (2)
Advantages of retro-reflective sensing (3)
Advantages of diffused scanning (2)
Disadvantages of ultrasonic sensor (3)
Features of the sensor (5)
