Apparatus for detecting a substance whose presence is to be detected in one or several chambers of a set of measuring chambers maintained at ultra-high vacuum and its use in the detection of leaks

摘要

Apparatus for measuring a parameter relating to at least one substance possibly present in at least one chamber of a set of measurement chambers kept under very low residual pressure. The chambers (12) are connected, on the one hand to a single vacuum pump installation (14), by low conductance elements (18) offering great resistance to the passage of molecules, and on the other hand, to a device (23) for measuring the parameter common to the set of chambers (12) by a selector (20) allowing each of the chambers (12) to be put in communication successively with the device (23) for measuring the parameter. The invention is particularly suited for measurement of the hydrogen content of the liquid sodium in a steam generator of a fast neutron nuclear reactor.