Allied electronics manufacturing co proffes disortion factor meters [model dfm-02], that are meant to measure total hormonic contraction from 0.1 per cent to 100 per cent in 5 ranges, in ithe frequency range of 20hz to 20 khz. These factor meter can also be used as ac millivoltmeters. The meters measure acv signal from 10 mv to 30 vrms. The distortion factor metrs have amplifiers and attenuator stage, fundamental suppression stage, buffer stage, ac millivoltmeter stage and ic regulated power supply stage. The instruments use modern transistor and ic circuitry. The technical specifications include: distortion [fsd] of 1, 3, 10, 30, & 100 per cent in 5 ranges; 1 v, 3 v, 10 v , and 30 v [rms] ac voltage range; frequency range of 20hz to 20 khz, in 3 decade ranges, ie, 20 hz to 200 hz, 200 hz to 2 khz, 2khz to 20 khz; 250 k ohms input impedance; accuracy of per cent at fsd; and supply voltage of 230 v to 50 hz. The instruments are housed in strong and elegant metal cabinets and are offered in dimensions of 12 1/2" [w] x 5 1/2" [d] x 1/2" [h].
