Berkeley Model 1000B Decimal Scaler (ca. 1949-1951)

Manufactured by Berkeley Scientific Company of Richmond California, the Model 1000B was described in May of 1949 as “the most convenient portable scaler ever designed.” This claim was hard to dispute. Determining a count with a binary scaler was a cumbersome process, but not so with the Model 1000B—the count was read directly from the illuminated numbers. The Model 1000B employed three decade scales which provided an effective scale of 1000. Of course, the highest count that could be displayed on the decade scales was 999. When the count went to 1000, the four-place mechanical register turned over to 0001 and the decade scales registered 000.

Berkeley Model 1000B Decimal Scaler

Designed to be used with a GM tube, the Berkeley Scientific Model 1000 was among the first commercially available decimal scalers. The Model 1000B was introduced in late 1948 and featured at the March 1949 Institute of Radio Engineers show in New York City. It featured, for the time, fairly advanced features, e.g., plug-in subassemblies for ease of servicing and an r-f type electronically regulated HV supply. By 1952 however, it had been superseded by other Berkeley Models (e.g., the Model 110). 

Scale: 0-1000 counts

High voltage supply: 100-2500 volts

Size: 6.25” x 7.25” x 12”

Weight: 14 pounds

Built-in preamplifier

Donated by Ron Kathren.


  • Berkeley Scientific Co. Richmond CA.
  • Model 1000 decade scaler, Nucleonics March 1948 p 84.
  • Model 1000B scaler, Nucleonics May 1949 p 93; Nucleonics January 1950 p99.
  • Atomic Energy Commission Radiation Instrument Catalog, page CGM-19C, date March 1, 1949.
  • Ron Kathren, personal communication.