publication_number US 2008035845 A1 abstract the inventive apparatus measures workfunction values using deflection of an electron beam without direct contact of the electron beam with the sample surface the apparatus mounted within a vacuum chamber includes an electron gun a position sensitive electron detector and a sample the sample is located such that an electron beam emanating from the gun can approach the surface and then be deflected into the position sensitive electron detector workfunction values are then derived from a measured deflected electron position distribution application_number US 68569307 A description in a preferred embodiment of our invention electrons from the electron gun 1 situated in front of a sample surface 2 as illustrated in fig1 are deflected by an initial applied negative potential on the sample v o the electron trajectories 8 are such that they are to be collected at the detector 6 7 which is located symmetrically in front of the plane of the surface the detector comprises two overlapping conducting collector plates 6 and 7 the negative electron currents collected by the two plates are amplified by the differential amplifier 4 and the integrator 5 integrates a difference signal 10 the integrator output signal 9 is then applied to the u201c positive u201d end of the fixed but floating bias supply module 3 if the.