Rare Gamma Monitron II Atomic Radiation Detector from Oak Ridge Nuclear Labs For Sale -

This listing is for a Very Rare Monitron Mark II Gamma Radiation Detector, designed and built at Oak Ridge National Labs in the 1970s. The ORNL logo may be seen on the front panel (partially scratched out) and on a solid state relay inside the unit - please see pics.In the ORNL Instrumentation & Controls Division\'s Biennial Progress Report (Sept 1, 1974 to Sept 1, 1976) F. M. Glass, W. T. Clay and R. A. Maples wrote:An ionization chamber, electrometer-type gamma monitron was designed to replace the Q-MS4 monitron. which is a 25-year-old design. One reason for replacement is that some of the components in the Q-1154 monitron are no longer available. Since many of these instruments are used at ORNL. a replacement was required that would perform the same functions and would be as dependable as the old monitron. No commercially available instrument could be used as a replacement without extensive modifications or creation of interface equipment to make it compatible with ORNL systems. Therefore, this Mark II monitron was designed.The new monitron is functionally similar to the old instrument, including the spectral response of the chamber and the relay logic of the auxiliary alarm circuits. Since the chassis connectors are the same as those on the older instrument, they can be plugged in existing systems without connector changes or the use of adaptors. The new instrument is inherently stable. It is much smaller and costs less to produce than its predecessor. An experimental model was tested for more than a year, with satisfactory results. The prototype was completed and documentation is near completion.It is a fascinating example of hybrid technology, using both a vacuum tube (an 0G3/85A2 voltage reference tube) and semiconductors (UA741HC op-amps and numerous transistors, etc). The ionization chamber is huge, measuring approx. 13\" tall by 7\" in diameter. It is in good cosmetic condition, for its age, with scuffs, scratches, marks etc.Prior to listing it was powered on: at first the needle wobbled a tiny bit occasionally, presumably due to background radiation. After a little while, it climbed, first triggering the amber \"Caution\" light and then the red \"Hi-Level\" light. Relays were heard operating when these alarms were triggered. We suspect that the most likely cause is a bad capacitor, but we do not guarantee that to be the case. No power cord is included. Due to the age of this item and the fact that older components can fail at any time, it is sold as-is, as a collectible with no guarantee of functionality and no guarantee that you will obtain the same results that we did.This is the only one being offered for sale anywhere in the USA - don\'t let it get away!

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