This article presents the proof-of-principle of a new sensor capable of detecting the position of the interface between two fluids.

To take full advantage of the resolver's potential, you have to compensate for error sources. Simulating resolver and cable functions go a long way toward helping you achieve this goal.

A new generation of inductive proximity sensors are engineered to withstand the high pressures now common in fluid power applications.

A Machine That Watches Dec 1, 2006 By: Bill Silver

During an automated manufacturing process, the product typically moves along a production line at either constant or variable speeds. The first task of optoelectronic inspection is to discard that motion. For example, machine vision systems use triggers and shutters and photoelectric sensors use gates to freeze the object at a particular point in time so that it can be analyzed.

Linear Hall sensors generate a DC output voltage proportional to the strength of an applied magnetic field and can be used for high-resolution angle sensors when placed near a diametrically magnetized magnet. The rotating magnet generates a sinusoidal waveform, one full wave per revolution. This type of setup can be used only for a limited angular range because the output voltage (in relation to the rotation angle) is ambiguous at angles >90? in both directions from the zero crossing point.

When Michael Faraday introduced the concept of an electric field, little did he realize how far science would run with the idea. Today, engineers are using electric fields to sense the presence of other objects without relying on physical contact. Referred to as e-field sensors or capacitance sensors, they are becoming more and more prevalent in a wide range of inexpensive and long-lasting applications. When you take a closer look at how they work, you quickly see why their popularity is growing.

Logging linear movement can be a complicated and expensive business. A variety of measuring systems can be used, depending on the accuracy required and distance to be measured. The simplest of these is the sliding potentiometer, which supplies a variable resistance proportional to the distance of travel. Incremental or absolute linear encoders can have accuracies of <1 ?m at lengths of several meters. Simple applications, such as level controllers, lift magnets, seat adjusters, motion sensors, or noncontact sliding switches, however, require the measurement of distances from a few millimeters to several hundred centimeters—as inexpensively as possible and without contact between the components. Magnetic encoders based on Hall sensors have long been successfully deployed for the detection of rotational motion [1].

The development of "active," noncontact sensors based on Hall effect, magnetoresistive, and variable-reluctance transformer technologies is penetrating the established market of "passive," contact sensors—and increasingly taking market share for automotive speed and position applications, says market research firm Strategy Analytics. "This is being driven by the need for improved reliability as well as increased functionality and accuracy," notes senior analyst Simon Schofield.

Electrolytic tilt sensors are inexpensive to buy and use, and offer good repeatability and reliability. Their sensitivity to both internal and external influences, however, makes them complex devices that should be understood before installation and operation.

In the last two decades, the development of fiber-optic sensors has led to the creation of devices and systems that can measure more than 60 different parameters. Here's a look at the physical underpinnings of the light-guiding operation of fibers and an overview of the fundamental field manipulation techniques used in these sensors.