Non-contact Position Sensing Using Optical Sensors

Photodetectors that measure the brightness of light sources find use all around us.

They are contained within such everyday items as cameras, bar-code readers, and laser printers. They are a mainstay in most scientific instruments used to measure light intensity or color.

But there is another class of optical detectors unrelated to light source brightness measurements, per se. And though these devices find use in a wide range of applications, many technologists are unfamiliar with them.

For example, medical researchers use such detectors to track the high-speed patterns of human eye movement, and to perform 3-D modeling of human motion. Optical scientists rely on such devices to align lasers, light sources, and mirrors to within fractions of microns. This technology is incorporated into ultra-fast, accurate auto focusing schemes for a variety of optical systems, such as microscopes. And such industrial measurements as machine tool alignment and vibration analysis are performed with these detectors.

Rather than quantifying the brightness of a light source, these types of measurements are concerned with finding its position in space. As such, this category is generally referred to as optical position sensing, and includes measurements of:

angle	straightness	location
height	centering	surface uniformity
distance	movement	vibration

 

UDT Instruments has integrated this detector technology into a number of specialized optical instruments, which, as we shall see, are being creatively applied to a wide range of measurements in science and industry.

Tutorial

Position Sensing Instruments

Electronic Autocollimators
Model 301-DIV Position Sensing Amplifier
Model 431 X-Y Optical Position Indicator
Model 531 X-Y Optical Position Indicator

Model 501 Dual Channel Position Amplifier

Accessories