Kaman Releases Non-Contact Displacement Sensors Designed for Defect Detection

November 17, 2020 by Robin Mitchell

Kaman announced a new AMS family of high precision non-contact displacement sensors for industrial and commercial applications.

Kaman Sensing Technology

Kaman Precision Products is an American company that specializes in high-performance, precision non-contact measuring systems utilizing inductive technology. Kaman provides a configuration and customization of its products to help engineers achieve solutions. 


Kaman Sensors logo. Image courtesy of Kaman


The company was founded in 1945 and operates as an umbrella under the parent company Kaman Corporation, is headquartered in Middletown, CT. The company and has manufacturing sites in Orlando, Florida, Colorado Springs, and Tucson. 


What are Displacement Sensors?

Displacement sensors detect the displacement between an object and the sensor itself. Unlike proximity sensors, displacement sensors provide distance measuring and utilized for positioning applications. Displacement sensors can use a whole range of different technologies depending on the target application. Common displacement technologies include laser and ultrasound. A signal is emitted from a transducer, and the time taken for the signal to bounce off the object and return is recorded. 

Knowing the speed and distance of the emitted signal can quickly be determined using the seed x time formula. However, not all applications can utilize light or sound as these don’t always work with all mediums, and they often require a clean atmosphere to operate (i.e., lack of dust, vapor, and obstacles).

One method for measuring displacement is with the use of eddy currents. An inductor coil has an AC current passed through it, and this results in a rapidly changing magnetic field generated by the inductor coil. When a ferrous surface approaches the inductor, the changing magnetic fields induce a current in the ferrous surface (i.e., eddy currents). This results in the formation of an opposing magnetic field. 

This causes the reactance of the inductor to change (the load on the inductor is now increasing). If the circuit is configured as an oscillator, the frequency of oscillation will change. If the frequency is fixed, then the result will decrease the voltage across the inductor. The change is detected. The size of the change also indicates the distance between the surface and the inductor which determines the distance. 


Kaman's new AMS range

Kaman's new AMS range is inductive non-contact displacement sensors that provide engineers with a high-performance, high-precision sensor for use in a wide range of different environments. The AMS range is designed for operation in environments with pressure from 500 psi to 22,500 psi, does not require a magnet on the target surface, and will work with any ferrous target (e.g., iron, steel). 


The AMS sensor range. Image courtesy of Kaman


The sensors can determine the displacement to a surface through a wide range of atmospheres and non-conductive surfaces, including oil, water, gas, and dust. The sensors are rated for IP-67, meaning they are dust-tight and can be submerged in water up to 1 meter deep. 

As standard, the AMS range of sensors comes with a flanged design, an AS4320 pressure port compatible, and has both head style configurations with hermetic options available. 

Regarding technical specifications, the AMS range has a resolution of 1 micron for displacement sensing, has a 12.5 kHz frequency response, output voltages between 0V to 10V and 0V to V5V (4-20mA), and a power supply requirement of 12V to 28V. The AMS operating temperature range is -40°C to +120°C. 



The AMS range is designed for condition monitoring, speed sensors, shaft runout, and defect detection. These sensors target industries such as military, aerospace, industrial monitoring, UVAs, and process control.