New techniques for the non-contact measurement of displacer motion of a miniature split-Stirling cryocooler

✍ Scribed by Y.P. Yang; B.J. Huang; F.M. Chen; S.B. Chien; T.F. Shieh

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 699 KB
• Volume: 36
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(96)00010-0

✦ Synopsis

This paper proposes optional methods to calibrate the static sensitivity of the measurement of displacer motion inside the cold finger of a split-Stirling cryocooler. The relative displacement measurement method, as previously proposed, required that the regenerator matrix material should have such a high magnetic permeability that the linear variable-differential transformer (LVDT) could measure the displacer motion without large signal amplification. This would be impossible for low-permeability materials, e.g. stainless steel 316L and 304L, contained in the displacer. Therefore, three options are proposed for the calibration of static sensitivity: contact, purge or dynamic calibration methods. Temperature compensation is also found to be necessary to transfer the LVDT voltage to the true displacer displacement when performing the non-contact measurement of the displacer motion.