Jordan "No Name" Civil Defense Meter (ca. 1962)

This instrument, there is no model number or other type of identification, was produced by Jordan Electronic Mfg. Co. Inc., of Culver City California.  It appears somewhat similar to the Jordan  Radector but would seem to have been intended for civil defense purposes.  Jordan was involved to some degree in the development of civil defense instruments, according to the 1961 annual report of the Office of Civil and Defense Mobilization: "The Jordan Electronics Division of the Victoreen Instrument Co. produced new prototype shelter survey meters following redesign of an existing prototype radiological remote-reading shelter survey meter." Whether or not this particular instrument is one of the prototypes referred to is not known.

Both this instrument and the various versions of the Jordan Radector employed a Neher-White ionization chamber. This chamber had several interesting features: its current drove the meter directly (in a logarithmic mode) without any type of amplification; the electrometer tube was sealed inside the chamber; the chamber was of all steel construction; and it was filled with argon at high pressure (Neher’s principal field of study was cosmic radiation, a field in which the use of high pressure ion chambers was commonplace).  

There is a sticker on the side of the instrument (not shown in the photo) that reads "On loan from State of California Disaster Office."  There is also a circuit diagram on the inside of the case that seems to be dated 1955. The date 1962 is stamped on the inside of the case.

Detector: high pressure argon filled ion chamber.

Range:  Log scale,   0 to 500 R/hr  

Dimensions:      5.25” x 3.5” x 3”

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