Nielsen quickly adapted the Audimeter for television.

Nielsen's people meter, like its Audimeter, keeps a record of the times when a television set is on and the stations to which it is tuned.

The company notes, for example, that the people meter's sample of 4,000 households nationwide allows for more refined demographic data than the 1,700-household Audimeter sample.

While he pursued a doctorate, studying ways to measure radio audiences, he invented a kind of forerunner of the Nielsen audimeter.

In 1936, Arthur C. Nielsen acquired the Audimeter, which measured which radio stations a radio had been tuned to during the day.

In that year, Nielsen Media Research brought a new technology on line nationwide: the "Storage Instantaneous Audimeter," measuring minute by minute.

For television, Nielsen used a Mailable Audimeter which included a replaceable film cartridge that was mailed from the sample home to Nielsen every week.

In one panel, the television sets were hooked up to an Audimeter, a device that recorded the times when a set was on and the channels to which it was tuned.

Eventually, A.C. Nielsen developed the AudiMeter, or PeopleMeter, on which the Nielsen rating system was founded.

The NTI reports (called Pocketpieces) were issued monthly with ratings based on a combination of Mailable Audimeter estimates of TV usage and telephone coincidental estimates of program share.

The news was so shocking and hit with such impact; according to the Nielsen Audimeter Service, within 40 minutes of the first reporting of the assassination, the television audience doubled, by early evening, 70% was at their television sets.

According to The Television Will Be Revolutionized, Amanda D. Lotz states that during the 1960s and 1970s, Nielsen introduced the Storage Instantaneous Audimeter, a device that daily sent viewing information to the company's computers using phone lines and made national daily ratings available by 1973.