Highly evacuated electron tube with focusing electron gun and fluorescent screen inclined relative to the beam axis so that the path of the beam can be seen and the effects of electric and magnetic fields can be studied. The electron beam can be deflected using two methods:Electrically - using the electric field of the built-in plate capacitorMagnetically - using external Helmholtz Coils (B8A49529)You are also able to determine the fundamental electron charge-to-mass ratio (e/m) and study mean electron velocities using field cancellation.The Perrin Tube may be used to show that charge can be accumulated in the Faraday pail incorporated that the charge does not disappear when the filament is switched off and therefore that cathode rays must consist of charged particles. Electron deflection sensitivity may be measured using Helmholtz coils to deflect the beam.Cathode ray tube operation may also be demonstrated using a 'secondary coil' for the transverse field. The Perrin tube comprises a standard spherical glass body with a cylindrical neck containing a diode electron gun with filament and cylindrical anode and a Faraday's pail in the sphere at 45° to the axis. Connections to the diode electron gun are via 4mm sockets in the moulded cap and the Faraday's pail connection is via a 4mm plug in 1 of the side caps. The end of the sphere ihas an internal phosphor coating providing a luminescent screen.Technical Specifications:Maximum filament voltage: =7.5V AC/DCMaximum anode voltage: 5 kVMaximum capacitor voltage: 500 VTypical Operation at 4000V: Anode current: 1.8mA Beam current: 4µARequires the following products to operate:B8A49463 - Universal StandB8R02653 - EHT Power Supply - to power the anodeB8R07149 - EHT Experiment Leads (3 required)B8G85458 - Bench Power Supply - to power the filamentB8R06545 - 4mm LeadsB8A49475 - Helmholtz CoilsB8G85483 - College Power Supply Unit - to power the Helmholtz Coils