In his post, When Do You Specify An Inductive Sensor?, Shawn Day (Market Manager, Inductive Sensors) discusses selection criteria and application for inductive proximity sensors. In that article, Shawn focuses on what are sometimes referred to as discrete sensors – sensors that detect the presence of a metal target, and then turn on (or turn off). As Shawn points out, there are many, many applications for this type of discrete sensing.
But what if just indicating the presence or absence of a part is not enough? What if you need to know not only if a part is in a particular position or not, but rather you need to know exactly where the part is at any given point along its entire range of travel? That’s where analog, or continuous, inductive position sensors come into play.
Analog inductive sensors employ basically the same technology as discrete proximity sensors. That is, they use inductive coils to generate eddy currents that respond to a metal target. But, unlike discrete sensors, analog inductive sensors provide a continuously variable output, not just an on/off change of state.
Analog inductive sensors are available in numerous form factors. For example, tubular analog inductive sensors, which look just like their discrete cousins, and which typically use a single inductive coil, are used primarily for very short-range (short stroke) applications.
Block-style, or bar-style analog inductive sensors employ an array of coils, usually situated side-by-side, and are useful where longer linear ranges are needed.
Some applications for analog inductive include:
- Distance measurement
- Part thickness measurement
- Machine tool spindle position
- Position monitoring on grippers and clamps
- Material handling and automated assembly
For more information on analog inductive sensors, visit www.balluff.us