Short communication
β
R Blanpain; JP Delwiche; P MΓ©lon; F Prouvreur
π
Article
π
1977
π
Elsevier Science
π
English
β 151 KB
The problem of maintaining within predetermined values the level of liquid nitrogen in cold traps is sometimes difficult to solve, especially for vacuum systems which have to work unattended for long periods of time. Having tried several commercial devices, none was found to be entirely satisfactory