Test body length measurement system has internal pressure of compensation body adjustable by feeding gas in or out of compensation body independently of vacuum in measurement body to reduce required drive forces

摘要

The system has a variable length hollow measurement body (1) in which a vacuum can be produced mechanically coupled to a variable length hollow compensation body (2) containing a gas with an internal pressure. In order to reduce the required forces of a drive (1.6) the internal pressure of the compensation body can be adjusted by feeding gas in or out of the compensation body independently of the vacuum in the measurement body.