The "Ionometer" (ca. 1950s)


The Ionometer is an electroscope that indicates the cumulative exposure via a dial on the top of the unit.  The bottom of the device is a rotating knob with two positions: "charge" and "measure."   For what its worth, one definition of an ionometer is that it is a device used for measuring the intensity of ionizing radiation. 

It is very similar in its function to a direct reading pocket dosimeter  -  in fact, it could easily have been included in the Dosimeter section of the collection. The major difference is that the Ionometer is more easily read. The scale is 0 - 0.2R (0 to 200 milliroentgen), the range typical of most pocket dosimeters.

It was produced by the Nassau Distributing Company of New York. The only information I have about this company is that it was involved in a lawsuit in 1952.

As can be seen in the accompanying photo, all the lettering has been done freehand, something that suggests that it was a prototype.  This makes sense because it was sent to the Office of Civil Defense when the latter was looking for inexpensive radiation detectors/dosimeters for the public.

Size:  ca. 4 1/2" long and x  1" in diameter

Donated by Jack Greene

Museum Directory      Personnel Monitors  

Last updated: 05/10/11
Copyright 1999, Oak Ridge Associated Universities