Hewlett-Packard has made numerous significant contributions to the Yokogawa Instrument Collection and we will be showcasing a few of these as follows.

Model 400B Vacuum-tube Voltmeter (49 x 21 x 24 cm ). Manufactured by Hewlett-Packard in 1950

This voltmeter was widely used in electronics research and development as well as in production processes because of its high stability, sensitivity, and ability to handle a wide range of frequencies.

Model 200C Audio Oscillator (17 x 38 x 24 cm).  Manufactured by Hewlett Packard in 1941

This RC oscillator featured low distortion, high stability, and a widely variable dial. The frequencies were varied with a ganged-variable capacitor.  An earlier model of this oscillator, the 200B, was sold to the Disney Studios for use in the production of the Disney animation Fantasia, but the Model 200C was the more widely used device.