New VPG RTD Simulator With Built-In Climate Control Features TCR Down To ±1 ppm/°C For Precise Instrument Calibration

Vishay Precision Group, Inc. recently announced that its Vishay Foil Resistors brand (VFR) has introduced a new Bulk Metal Foil RTD Simulator resistor with built-in climate control. Designed to simulate resistance temperature detector (RTD) PT-100 and PT-1000 outputs for the calibration of RTD instruments, the device features a low nominal TCR of ±1 ppm/°C from -55°C to +125°C, +25°C ref., and load-life stability of ±0.005% after 2,000 hours of rated power at +70°C.

The device released today provides a faster, easier, and far less expensive alternative to decade boxes and electronic simulators for the calibration of transmitters, controllers, data acquisition, process control, and lab equipment in the field, shop, or control room. Each resistor comes with certification and features its specified temperature simulation — anywhere from -200°C to +850°C — clearly printed on the device for easy identification.

"The climate control capabilities of the RTD Simulator are provided by the inherently low absolute TCR of Bulk Metal Foil resistors, which itself results from two predictable and opposing physical phenomena within the composite structure or the resistive alloy and its substrate," said Yuval Hernik, senior director of application engineering for the VFR team. "The first is that the resistance of the alloy increases with the temperature. The second is that the coefficient of thermal expansion (CTE) of the alloy and substrate are different, resulting in a compressive force on the alloy when the temperature increases and a consequent decrease of the foil resistance. The two effects occur simultaneously, resulting in an unusually low predictable, repeatable, and controllable TCR."

The RTD Simulator offers power ratings to 0.6 W at +70 °C and a maximum working voltage of 300 V. The device features a resistance range from 10 Ω to 5 kΩ, with tight resistance tolerance to ±0.005% (50 ppm). Any conceivable ohmic value within this range, to six digits, is available with no additional cost or lead time effect.

Featuring a non-inductive (< 0.08 μH), non-capacitive design, the RTD Simulator offers a rise time of 1.0 ns with effectively no ringing, thermal EMF of 0.05 μV/°C, voltage coefficient of < 0.1 ppm/V, and current noise of 0.010 μVRMS/V of applied voltage (< –40 dB). The resistor withstands ESD spikes to at least 25 kV and is available with both lead (Pb)-free and tin/lead alloy terminal finishes.

Samples and production quantities of the RTD Simulator are available now, with lead times of five working days for prototype samples and six weeks for standard orders.

About Vishay Precision Group, Inc. (VPG)

VPG is an internationally recognized designer, manufacturer and marketer of: components based on its resistive foil technology; sensors; and sensor-based systems specializing in the growing markets of stress, force, weight, pressure, and current measurements. VPG is a market leader of Foil Technology Products, providing ongoing technology innovations in precision foil resistors and foil strain gages, which are the foundation of the company’s Force Sensors Products and its Weighing and Control Systems. The product portfolio consists of a variety of well-established brand names recognized for precision and quality in the marketplace. For more information, visit www.vpgsensors.com.

About VPG Foil Resistors

VPG Foil Resistors produces the most precise and stable resistors available. Distinguished by the premier brands Vishay Foil Resistors, Powertron, and Alpha Electronics, the VPG Foil Resistors portfolio includes discrete resistors and resistor networks in surface mount and through-hole (fixed-lead) configurations; customized chip resistor networks; precision trimming potentiometers; and discrete chips for use in hybrid circuits. These devices are used in applications requiring a high degree of precision and stability, such as in medical testing equipment, semiconductor equipment, precision measuring instruments, aerospace, and military applications. For more information, visit www.vishayfoilresistors.com.