Figure 1: Pressure controlled heat pipe calibrating furnace and controls.
Lancaster, PA – Mar 3, 2015 Advanced Cooling Technologies (ACT) announced today that they have recently delivered a pressure controlled heat pipe (PCHP) calibrator to a highly regarded German government calibration institution. The purpose of the calibration product is to calibrate up to 5 thermometers to a reference thermometer. The PCHP calibrator (shown in Figure 1) features a sodium heat pipe with the ability to operate between 600°C and 1,000°C and maintain a temperature stability of +/-5mK over a 2 hour period (some temperature data are shown in Figure 2). The heat pipe features 6 thermowells located within the vapor space of the heat pipe, maintaining a high degree of temperature uniformity between the thermometers. The transient stability of the heat pipe is maintained by actively controlling the pressure of the heat pipe’s vapor space, ensuring a stable saturation temperature within the heat pipe. The pressure is manipulated by changing the effective volume of the heat pipe, simply by moving a sealed bellows.
Figure 2: Temperature stability data from PCHP operating near 800°C.
ACT’s custom products group has supplied heat pipes as isothermal furnaces liners and blackbody cavities to the calibration industry since the company’s inception. The mature product line has not benefited from any technology advancements over the years. The pressure controlled heat pipe technology was initially developed on a NASA Goddard Phase II Small Business Innovative Research (SBIR) program several years ago, demonstrating temperature stability in a low-temperature spacecraft PCHP under varying power and sink conditions. “Translating aerospace R&D results to a high temperature calibration product was very challenging,” continues Dr. Richard Bonner, Manager of Customer Products, “I believe the strong collaboration between our R&D and product development personnel along with the perseverance of our talented team were the keys to our success.”