Coping with the application environment is one of the more complex issues that sensors must address. To survive in harsh environments, sensors manufacturers improve the ruggedness of their sensors in many different ways. Three recently announced products exemplify the differences.
For dusty and wet environments, Sensata Technologies ACW4 single turn and TCW4 multi-turn absolute Hall Effect sensors have a small over-molded, two-part modular construction. The 50-mm diameter by 24-mm thick sensors are encased in a thermoplastic polyamide shell. Since the thermoplastic is molded at low pressure, it can be economically produced in lower volume.
To work in high pressure, low temperature, and high-temperature conditions, Kaman Measuring takes a different approach for high-precision displacement sensors. Packaged in hermetically sealed, all laser-welded Inconel housings and using an Inconel-jacketed, mineral-insulated cable, the company’s KD-1925, KD-1950 and KD-1975 displacement sensors can function in operating temperatures ranging from -320°F to +1000°F and its displacement systems can withstand pressures up to 5000 pound-force per square inch (psi). While capable of handling rocket engine validation testing, the sensors can also handle the displacement sensing requirements of nuclear reactors, steam and gas turbines, chemical processes and high-temperature processing.
Higher-speed and higher-resolution analog-to-digital conversion for sensors and other systems that operate in high temperature and high electromagnetic environments require special design considerations. For those found in automotive and industrial applications, Microchip Technology developed analog-to-digital converters (ADCs) and a companion differential amplifier. The 12 new successive approximation register (SAR) ADCs in the MCP331x1(D)-xx family include the industry’s only one million samples per second (Msps) automotive (AEC-Q100) qualified 16-bit SAR. The companion MCP6D11 differential amplifier provides a low-distortion, high-accuracy interface.
