IM-113A/PDR GM Survey Meter (ca. 1960) 

The IM-113A, manufactured by Nuclear-electronics Corporation, is a beta-gamma GM survey meter that reads up to 20 mR/hr. While it has no speaker, there is a covered jack provided for headphone use. In addition, there is a light next to the meter face that indicates the count rate- each pulse is indicated by a flash of the light. The only control is the range switch.  

Unfortunately, I have not found any references describing the IM-113 and the tentative date for the IM-113A is based on a packet inside the case dated September 1960.    

Range: 0 0.2, 0 2.0, 0 20 mR/hr.

Size:  9 x  6" x  4.5"

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Last updated: 05/10/11
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