Bendix Prototype Ratemeter (ca. 1960)

Bendix ratemeter pocket dosimeter

While this amazing device looks like a standard pocket dosimeter, it is actually a ratemeter. The non-linear scale, viewed through the eyepiece in the normal fashion, reads out in R/hr. To be more specific, it measures exposure rates from 0 to 100 R/hr.

Bendix ratemeter pocket dosimeter

The information I have is that it dates from 1960 and that the fiber element is a 1013 ohm resistor.  Since it came from FEMA, it is likely that it might have been a civil defense prototype. In the early 60s, Bendix produced at least a couple of similar devices for civil defense purposes. One, the CD V-736, was included in their Family Radiation Measurement Kit. The 736 however, was not a true ratemeter—it had to be left in the radiation field for a specific length of time before the exposure rate could be determined. The other was the CD V-726 BX, an experimental prototype that never went into production.

Size: 4 3/8” long and 0.5” in diameter

Donated by FEMA courtesy of Carl Siebentritt.