DIFFERENTIAL MEASUREMENTS These differential measuring systems are a significant advance in precision measurement technology. They provide exceptional resolution, repeatability, and nulling accuracy for detecting the aligned/centered position of a conductive target relative to a pair of noncontacting sensors. For differential measurement applications, two precisely matched sensors per channel are positioned on opposite sides or ends of a target. In this sensor-to-target relationship, as the target moves away from one sensor, it moves toward the other an equal amount. Output is differential and bipolar. The electronically-matched sensors on opposing legs of the same bridge provide superior thermal stability.

The KD-5100 features superior thermal and long-term stability of 5x10E-6 inches/month or better provided in a small package size: just 2 x 2.12 x 0.75 inches thick. It has high sensitivity up to 10 V/mil (394 mV/micrometers). Its low power consumption is less than 2W @ ±15 Vdc typical.

Cryogenic applications Kaman builds an alternate version of the 20N sensor specifically for cryogenic applications. This sensor has internal expansion joints, and when screw mounted using a Belleville washer, effectively eliminates stress or temperature induced mechanical distortions. Kaman has confirmed optimum performance in liquid nitrogen at 70° Kelvin. Several aerospace applications make effective use of this sensor in a liquid helium environment at 4° K.

Vacuum applications Both sensor and KD-5100 electronics are used in vacuum applications down to 10E-6 Torr. The vacuum-compatible systems use a NASA-certified heat-sink compound. These systems have been specified for orbital platforms.

KD-5100 DIFFERENTIAL SUPER HIGH-PRECISION SYSTEM The hybrid for the KD-5100 is manufactured to MIL-H-38534. MIL-SPEC components are utilized throughout the electronics module wherever possible. The KD-5100 features rugged construction with a mean time between failures of better than 55,000 hours in a tactical environment, 238,000 hours in a space flight environment.

The small package size of the KD-5100 (just 2 x 2.12 x 0.75 inches thick) makes this system ideal for applications where space is a limiting factor.

Commercial differential systems The KDM-8200 differential system is a commercial version of the KD-5100. This system significantly reduces the cost of a differential system yet maintains most of the performance characteristics. Kaman achieved this by using high-volume packaging with discreet components and eliminating the MIL-SPEC requirements. These differential systems are ideal where weight, size, and power consumption are not critical.

Examples of Current Applications RELAY MIRROR EXPERIMENT The Relay Mirror Experiment (RME) demonstrated that a laser beam could be accurately relayed from the earth to an orbiting satellite 450 kilometers away and then back to a 3- meter target on the ground. A free-flying spacecraft functions as the orbiting laser beam relay system. The objective was to validate the stabilization, tracking and pointing technologies at military performance levels through a credible demonstration of a space-based relay mirror system. Kaman's KD-5100 differential sensors were used to precisely position the 60- centimeter relay mirror on the spacecraft payload to reflect the beams back to the target site. The KD- 5100 was instrumental in achieving relay laser beam pointing accuracy that was 16 times better than the experimental goal and line-of-sight stabilization that was 2.3 times better.

SUPER PRECISE LASER FOCUSING Laser microcolumn technology is being used to develop direct-write applications in semiconductor wafer manufacturing. Microcolumn architecture uses laser devices with column lengths of several millimeters, and offers high resolution, miniaturization, and new source technology possibilities. The technology is being used to develop both direct write applications and high- throughput mask patterning applications, and is being incorporated into products around the 0.1 micron generation. Kaman's KD-5100 sensors are used in this technology to precisely position the laser to allow exceptionally fine placement, critical dimensions, and alignment control.

Other applications include night vision systems, precision telescope positioning, and magnetic bearing shaft positioning.