Video shows Vishay Bulk Metal foil COTS resistors in action in RTD measurement systems

MALVERN, PA — Aug. 13, 2013 — Vishay Precision Group, Inc. released a new video that explores using Vishay Foil Resistors brand Bulk Metal Foil commercial off-the-shelf (COTS) resistors to calibrate and maintain the accuracy of precision temperature measurement systems using resistance temperature detector (RTD) sensors. The short video demonstrates the selection and use of foil resistors to simulate physical parameters in the calibration of RTD-based temperature measurements, and how the ultra-low-TCR precision resistors are nearly immune to drift over temperature and time, serving as the ideal reference to check against the RTD under any operating condition. With Bulk Metal Foil resistors, RTD-based systems can be recalibrated in harsh environments and hold their accuracy for several years.

RTD measurement instrumentation must maintain calibration regardless of the end user or application. Ultra-precision temperature accuracy is required for extended periods of time in a variety of extremely harsh environments, such as oil platforms, deserts, and the Antarctic. Resistors used in these applications must be rugged and impervious to heat and humidity, with low absolute TCR to simulate perfectly the value of the RTD at defined temperatures. Traditional standard resistors, however, are expensive, fragile, and do not provide the accuracy required.

The demo video highlights the characteristics of VFR's Bulk Metal Foil resistors for RTD calibration. RTD-based systems can be recalibrated with precision foil resistors instead of expensive certified physical standards, even in extreme operating environments. Rugged, tight-tolerance foil resistors with TCR of only 0.2 ppm/°C from -55° to +125°C and a long-term stability of 2 ppm per year (worst case) can be supplied to the exact resistance necessary to duplicate platinum, nickel, and copper temperature sensors at critical temperatures. Available with a hermetic seal 0066or ruggedness, the compact resistive devices can be trimmed to unique resistance values. Any conceivable ohmic value to six digits is available with an absolute tolerance to ±0.001%. Due to the devices' convenient built-in calibration factor, these values can be provided in only a few days at a low cost.