A standardized diode cryogenic temperature sensor for aerospace applications

Abstract

The model DT-670-SD cryogenic diode temperature sensor, manufactured by Lake Shore Cryotronics, Inc. has been used on numerous aerospace space missions since its introduction nearly 15years ago. While the sensing element is a diode, it is operated in a non-standard manner when used as a temperature sensor over the 1.4–500K temperature range. For this reason, the NASA and MIL-type test and performance standards designed to ensure high reliability of diode aerospace parts don’t properly define the inspection and test protocol for the DT-670-SD temperature sensor as written. This requires each aerospace application to develop unique test and inspection protocols for the project, typically for a small number of sensors, resulting in expensive sensors with a long lead time. With over 30years of experience in supplying cryogenic temperature sensors for aerospace applications, Lake Shore has developed screening and qualification inspection and test protocols to provide “commercial off-the-shelf (COTS)” DT-670-SD temperature sensors that should meet the requirements of most high-reliability applications including aerospace. Parts from acceptance and qualified lots will be available at a base sensor level with the ability to specify an interchangeability tolerance, calibration range, mounting adaptor, and/or lead extension for final configuration. This work presents details of this acceptance and qualification inspection and test protocol as well as performance characteristics of the DT-670-SD cryogenic temperature sensors when inspected and tested to this protocol.