Photoelectric applications with space restrictions, small part detection, high temperatures, or aggressive harsh environments may be solved using fiber optic sensors. These sensors allow the electronics to be mounted out of harm’s way while at the same time focusing the light beam on a small target. The sensing tips can be manufactured in a wide variety of housings for unique mounting requirements.
Fiber optic sensors require two components: a remote mounted amplifier, and the fiber optic cable(s). The amplifiers can be basic, with few features, or advanced with many configurable options and digital displays. The fiber optic cables are made of either plastic or glass fibers, each with advantages and application specific solutions.
Many applications, primarily those in the medical sciences and semiconductor industries, cannot be solved with fiber optic or miniature photoelectric sensors because they are physically too large to fit in the instruments. Additionally, the cables are typically not flexible enough to be routed through the instruments. Today, highly flexible and miniature sensors are are being incorporated in other industries due to today’s demands of smaller machines and tools.
MICROmote® sensors are miniaturized photoelectric sensors with separate amplifiers that are also available with a variety of functionalities. Their highly flexible, electric sensor cables make them a genuine technical alternative to conventional fiber optics. The photoelectric sensor heads have extraordinarily small dimensions, excellent technical characteristics, and outstanding flexibility for application-specific solutions.
Similar to fiber optic sensors, these micro-optic photoelectric sensors function as either a through-beam or diffuse type sensor with comparable sensing ranges. Unlike fibers, the wired sensing heads are inherently bifurcated type cables so that there is only one connection to the amplifier.
Unlike conventional fiber optic cables, there are no significant coupling losses, minimum bending radius and cyclic bending stresses. The patented precision elements produce extremely small beam angles with sharply defined light spots unlike standard fiber optics where the beam angle is a function of the fiber geometry. Additional lenses must be used if the light beam of a fiber optic cable must be focused which adds to the costs.
MICROmote® photoelectric sensors for water detection use a specific wavelength at which water absorbs more light. This significantly simplifies the detection of liquids with high water content using optical sensors. The combination of an ultra-compact design and powerful micro-optics allows for reliable use in capillary tubes where other sensing devices are stretched to their limits.
These sensors can also be used as precision tube sensors for detecting bubbles through use of either light refraction or attenuation through the air, or liquid column within the tube. They provide excellent detection for even the smallest air-to-liquid transitions and are reliable for all liquid types, even clear liquids.
In addition, these sensors are designed to detect free-floating microbubbles in transparent liquids. Microbubbles refer to little gas bubbles with dimensions smaller than the inside diameter of the tube. Uniform lighting is achieved in the liquid column by using a concentrated arrangement of multiple light beams with very uniform intensity distribution. Gas bubbles that move through this field induce a signal jump in the built-in photoelectric receiver elements
For more information on this technological alternative to fiber optics visit www.balluff.com.