VFR resistors are suitable for use on Mars
VPG's Vishay Foil Resistors (VFR) brand has released a video demonstrating the advantages of using Bulk Metal Foil resistors for applications operating in extreme temperatures. The video compares the TCR performance and resistance stability of Bulk Metal Foil with thick film and thin film technologies when exposed to the temperature conditions on Mars.
Most resistors perform well in controlled, room-temperature environments. However, there are some applications that operate under temperature conditions requiring optimal TCR performance and resistance stability, such as weather stations in the South Pole, solar panel arrays in Death Valley, and the harshest environment of all: space. To illustrate this point, the video, hosted by VPG senior R&D engineer Richard Zuratt, features a lab demonstration replicating the daily temperature cycle on Mars.
For the demonstration, a Kelvin scanner and precision DMM record the TCR and change in resistance of thick film, thin film, and Bulk Metal Foil 1206 1kΩ resistors when moved from room-temperature water (+23°C) to dry ice (-50°C) to boiling water (+100°C) - and then back to room temperature again. While the thick film and thin film devices demonstrate poor TCR performance and a significant change in resistance after exposure, the Bulk Metal Foil resistor maintains a low TCR and experiences a near-zero resistance change after exposure to these extreme temperatures.
Yuval Hernik, Senior Director, Application Engineering, VFR, comments: "VFR resistors are hardly affected at all by the temperature swings encountered in a typical day on Mars. Thin film and thick film technologies, on the other hand, not only offer worse performance, but a single temperature cycle changes their resistance permanently. Imagine what would happen to these resistors after an extended stay aboard the Rover Curiosity. That's why Mars needs Bulk Metal Foil resistors, as this video so dramatically shows."