Tuesday, May 11, 2010

sensors for distance measurement (2)

optical analog sensors:
This sensor is suitable for applications which require analog measurement of the distance between the sensor and the object. The sensor is capable of direct or scanning mode operation. Bright objects reflect transmitted light better than dark objects. Output voltage is dependent upon the brightness of the object to be measured.

Sensors for Distance measurements

inductive analog Distance sensor:
inductive analog sensors are ideal for applications involving relatively short metal target travel They provide precision, non-contact position measurement by varying its electrical output in proportion to the position of a metal target within its working range.

linear potentiometer:
Linear Potentiometers are well known displacement transducers. The working principle is voltage division on a hybride conductive film. It is possible to get different housing and mounting types, like versions for hydraulic cylinders, with spherical bearrings, clamping jaw mounting or sprung loaded.

ultrasonic sensor:
work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance to an object.

Tuesday, April 20, 2010

stress and strain and strain guage

Stress : Force that produces strain on a physical body.
stress= F/A
Stress (N/m2)
F: Force (N)
A: Area (m2)


Strain: Deformation of a physical body under the action of applied forces.
e= ΔL/L= L-L/L
e : strain
L= Original length
Δ= change in length

Strain guage:
It is a device used to measure the strain of an object। the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern.

Wednesday, April 14, 2010

pressure and pressure sensor

Pressure:
The force applied to a unit area of surface.
P=F/अ
प:pressure(Pa)
F= force(N)
A= cross sectional area(m2)





Pressure sensor: An instrument component that detects a fluid pressure and produces an electrical signal related to the pressure. Also known as electrical pressure transducer.

Tuesday, April 13, 2010

sensors for force and pressure

Force:
the influence that produces a change in a physical application.

F= m . a
F= Force (N)
m= Mass (kg)
a= Acceleration (m/s2)


types of forces:
gravity
friction
air resistance


Force Sensor is defined as a transducer that converts an input mechanical force into an electrical output signal. Force Sensors are also commonly known as Force Transducers.