Abstract :
Methods at present in use for determining form factor are outlined, and their good and bad features are indicated. A description is given of a new instrument, incorporating a copper-oxide rectifier, which gives direct indications of the form factor. Test results show that the instrument is sensibly independent of variations of voltage, frequency, and temperature. The form factors of waves of varying shape are shown to be correctly indicated, except in the cases of re-entrant waves, and rectangular waves of a particular type. The effects of this last class of waves are discussed in an Appendix.