ipt sensor

7/31/2019 Ipt Sensor

http://slidepdf.com/reader/full/ipt-sensor 1/33

A sensor (also called detector) is a converter that

measures a physical quantity and converts it into a signal

which can be read by an observer or by an (today mostly

electronic) instrument.



*TEMPERATURE

*ULTRASONIC

*FLOAT



*GAS*BRAKE FAILURE*SMOKE EMISSION*AUTOMATIC WIPER CONTROL



A Passive Infrared sensor (PIR sensor) is an

electronic device that measures infrared (IR)

light radiating from objects in its field of view.PIR sensors are often used in the construction

of PIR-based motion detectors (see below).

Apparent motion is detected when an infrared

source with one temperature, such as a human,

passes in front of an infrared source with

another temperature, such as a wall.



WORKING PRINCIPLE?

The PIR Sensor senses the

motion of a human body bythe change in surrounding

ambient temperature when a

human body passes across.



A person entering a monitored area

is detected when the infrared energy

emitted from the intruder's body is

focused by a Fresnel lens or a mirror

segment and overlaps a section on

the chip that had previously been

looking at some much cooler part of the protected area. That portion of

the chip is now much warmer than

when the intruder wasn't there.



This sensor can be used for most

indoor applications where no

important ambient light is present.

For simplicity, this sensor doesn't

provide ambient light immunity,

but a more complicated, ambient

light ignoring sensor should be

discussed in a coming article.However, this sensor can be used to

measure the speed of object moving

at a very high speed, like in

industry or in tachometers.



It is the same principle

in ALL Infra-Redproximity sensors. The

basic idea is to send

infra red light through

IR-LEDs, which is thenreflected by any object

in front of the sensor.



Then all you have to do is to pick-up thereflected IR light. For detecting the reflectedIR light, we are going to use a very originaltechnique: we are going to use another IR-LED, to detect the IR light that was emittedfrom another led of the exact same type!

This is an electrical property of Light EmittingDiodes (LEDs) which is the fact that a ledProduce a voltage difference across its leadswhen it is subjected to light



A gas detector is a device which detects thepresence of various gases within an area, usuallyas part of a safety system. This type of equipment

is used to detect a gas leak and interface with acontrol system so a process can be automaticallyshut down. A gas detector can also sound analarm to operators in the area where the leak isoccurring, giving them the opportunity to leavethe area. This type of device is important becausethere are many gases that can be harmful toorganic life, such as humans or animals.



There are several types of

flame detector. The optical

flame detector is a detector

that uses optical sensors todetect flames. There are

also ionisation flame

detectors, which use

current flow in the flame to

detect flame presence, and

thermocouple flame

detectors.



An LDR (Light dependent

resistor), as its name

suggests, offers resistance

in response to the ambient

light. The resistance

decreasesas the intensity

of incident light increases, and vice versa.

In the absence of light, LDR exhibits a resistance

of the order of mega-ohms which decreases to few

hundred ohms in the presence of light.



It can act as a sensor,

since a varying voltage

drop can be obtained inaccordance with the

varying light. It is made

up of cadmium sulphide(CdS).



INDUSTRY PURPOSE

SENSOR



A pressure sensor measures

pressure, typically of gases or

liquids.

Pressure is an expression

of the force required to stop a

fluid from expanding , and is

usually stated in terms of force per unit area. A pressure

sensor usually acts as a transducer; it generates a signal

as a function of the pressure imposed. For the purposes

of this article, such a signal is electrical.

http://en.wikipedia.org/wiki/File:P_sensors.JPG



A pressure sensor measures pressure,

typically of gases or liquids. Pressure is an

expression of the force required to stop a fluidfrom expanding, and is usually stated in terms

of force per unit area. A pressure sensor

usually acts as a transducer; it generates a

signal as a function of the pressure imposed.

For the purposes of this article, such a signal is

electrical.



A semiconductor piezo-resistance dispersion

pressure sensor has a semiconductor distortion

gauge formed on the surface of the diaphragm,and it converts changes in electrical resistance

into an electrical signal by means of the piezo-

resistance effect that occurs when the

diaphragm is distorted due to an external force

(pressure).



A proximity

sensor is a sensorable to detect the

presence of nearby

objects without any

physical contact.



A proximity sensor often emits anelectromagnetic field or a beam of electromagnetic radiation (infrared, for instance),

and looks for changes in the field or return signal.The object being sensed is often referred to as theproximity sensor's target. Different proximitysensor targets demand different sensors. For

example, a capacitive or photoelectric sensormight be suitable for a plastic target; an inductiveproximity sensor always requires a metal target.



A humidity sensor also

called a hygrometer,

measures and regularly

reports the relativehumidity in the air.

http://www.wisegeek.com/what-is-humidification.htm

http://www.wisegeek.com/what-is-a-hygrometer.htm

http://www.wisegeek.com/what-is-relative-humidity.htm




http://www.wisegeek.com/what-is-a-hygrometer.htm

http://www.wisegeek.com/what-is-humidification.htm

ipt sensor

Documents