AVS 50th International Symposium
    Vacuum Technology Wednesday Sessions
       Session VT-WeP

Paper VT-WeP1
Temperature Characteristics of a New Static Expansion Vacuum Standard

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: P. Carroll, National Physical Laboratory, UK
Authors: J.C. Greenwood, National Physical Laboratory, UK
P. Carroll, National Physical Laboratory, UK
Correspondent: Click to Email
The uncertainty in the pressure generated in vacuum standards is often dominated by temperature contributions. In equilibrium, gradients across the system vessels make it difficult to assign a temperature to the gas contained inside. Gradients between vessels can also contribute to errors in the calculation of the generated pressure. To investigate the temperature characteristics of a new Static Expansion vacuum standard at NPL a series of measurements were made using an array of thermister thermometers located at over 100 distinct locations. This level of monitoring is not practical for normal operation, however, the temperature distribution for the system has been mapped so that probe locations for representative temperature measurements have been identified for normal operation. An indication of the worst case error is given together with the improvement in uncertainty for optimally located temperature probes.