Abstract: A diamond identification apparatus is disclosed, the diamond identification apparatus comprising a support platform for receiving a gemstone at an observation position, a first light source arranged to emit light at a predetermined angle towards the observation position and a first photodiode arranged to detect an amount of light from the first light source being reflected from the gemstone at the observation position. The diamond identification apparatus further comprises a second light source arranged to emit light towards the observation position, a second photodiode arranged to detect light from the second light source that passes through the gemstone at the observation position and a processor unit.

Abstract: A precious metal assay method which includes the steps of forming an electrolytic cell comprising an anode specimen and a reference cathode, driving a ramp input into the electrolytic cell, measuring a resulting current through the electrolytic cell over a period of the ramp input. The assay value may be determined by comparing the locality, slope and peak or area of a current response of the resulting current against the localities, slopes and peaks or areas of a list of current responses of known precious metal compositions from an empirical look-up table and displaying the assay value on an electronics display.

Abstract: Inductive-systems (1,2) comprising a first part in the form of a printed coil (11,21) and a second part in the form of a non-printed coil (12,22) coupled serially to each other may have a relatively large inductive-value and still be relatively small in size. The nonprinted coil (12,22) comprises an air coil. The total inductance of the inductive-system (1,2) is substantially equal to an inductance of the printed coil (11,21) plus an inductance of the air coil plus a mutual inductance, which depends on an overlapping area between the printed coil (11,21) and the air coil. One end of the non-printed coil (12) is coupled to a center end of the printed coil (11), and the other end of the nonprinted coil (12) and an outer end of the printed coil (11) constitute ends of the inductive-system (1), to couple both coils (11,12) compactly.

Abstract: In a local oscillator for a tuning arrangement for both TV and FM signals there is substantial risk of parasitic oscillation. A special provision is disclosed for effectively reducing this risk. The special provision is a connection of a damping resistor (R1a) for suppressing parsitic oscillations between ground and a junction (J2) of a parallel LC resonator of the local oscillator.