The prototyping and evaluation of a liquid level alignment monitoring scheme for the SDC detector

To know the real time vertical position and shape of the base, barrel toroid, and detector elements of the SDC detector for the Superconducting Super Collider (SSC), a distributed elevation monitoring system with long term stability is essential. The authors have designed, built, assembled, and tested six point and ten point matrices of interconnected point liquid level sensors and a reference reservoir using precision capacitive proximity sensing. They have tested three commercial sensors and have expanded their initial setup based on best test results. Long term measurements on the fixed position setups indicate long term raw sensor standard deviations of 15-30 μm and intrinsic systematic deviations of 5-10 μm as indicated by sensor differences at a given point. Temperature corrections will improve these numbers and a detailed correction study is in progress. The system appears adequate in all respects