Baird Atomic Model 135 Scaler (ca. 1961

Baird Atomic Model 135 Scaler (ca. 1961 - 1965)

The Model 135 scaler was manufactured by Baird-Atomic, Inc., of Cambridge Massachusetts . It was described in January 1962 as “a new all-electronic” scaler “which combines a 5 decade, 5 micro-second scaler and an electronic timer on one chassis . . is excellent for both general lab counting work and for use with the most sophisticated automatic sample changing systems.” The phrase “all-electronic scaler” referred to the fact unlike typical binary and decade scalers, the Model 135 did not require a mechanical register. The complete count was indicated by five glow transfer counter tubes – in 1952, Baird Atomic (then Atomic Instrument Company) was the first to incorporate glow transfer tubes into nuclear scalers.

The Baird Atomic Model 135 could either count for a preset time or measure the time required to obtain a preset count.

When a glow transfer tube is viewed from the end, a dot of light can be seen moving in a circular path. The dot actually moves through ten discrete positions when making a complete circuit. Each position is numbered (0 to 9) on the outer edge of the tube, much like the hours on a clock. As such, the count is indicated by the position of the dot of light.

Size: 18" x 19.25" x 9.75"

Range: 0 -100,000 counts

Time: 0 - 10,000 seconds

High Voltage: 0 - 2,500 volts

References

Nucleonics January 1962 p. 79;

Nucleonics May 1952, p. 85.

Museum Directory Monitors, Scalers