Instrument moving device esp. for neutron flux detector - is pref. gas operated cylinder piston unit with detector on piston rod

摘要

Electrical measurement appts. esp. for neutron flux distribution measurements in a nuclear reactor, comprises a piston-cylinder unit (14, 16) mounted in a standpipe (12) in the top slab (10) of the concrete pressure vessel; the piston rod (16) projects out through the bottom of the cylinder (14) as a measuring sensor (24, 38) under the action of fluid entering the cylinder, esp. gas. When the measuring sensor (38) reaches its measuring position (MP), an electrical contact (26, 28) is closed in an instrument conductor (47) leading to an indicator instrument. Pref. the piston rod comprises a guide rod (24) passing out through the cylinder having a neutron flux detector or other instrument (38) mounted at its lower end. Used partic. for neutron flux distribution measurements in a gas-cooled reactor, where the distance to be travelled by the detector head is up to 10 m. The entire appts. can be contd. in a dia. of approx. 50 mm.