A Revolution: HP 400AC Voltmeter
When Dave Packard designed the HP 400AC voltmeter in 1948, he was on to something big. This product launched the beginning of a voltmeter product line that would continue for 50 years and more than a dozen generations. The device’s early success was due in part to its advertising, which conveyed the technical benefits of the products in simple, clear terms.
( C ) HPCA