'Rich 100' 'Condensation Nuclei Counter' Repair
I've been doing research into fungi, and after doing research on this device available at a university surplus store I snagged it as soon as I could
this Friday. It had been sitting there unloved for a couple months.
I thought I'd journal my repair job and utilization of it for any interested readers.
A condensation nuclei counter (CNC) is capable of measuring the size distribution of fungi spore/fragments, thus my interest.
I am doing citizen science on fungi in my spare time, independently and without financial interest. There are not enough fungi researchers [1].
The technology behind the Rich 100 model was invented by Mr. Theodore A Rich et al. The company they formed, Environment One, still exists! They're now owned by Berkshire Hathaway, and appear to have
largely divested into the commercialization of other technologies. Systems including CNCs appear to have done many interesting things, like sniffing
out the location of diesel burning submarines via their emmisions (sorry forgot source, might be in Mr. Rich's patents), pollution characterization, and most interestingly to me, characterization of radioactive pollution from nuclear tests. Mine appears to have originated from Los Alamos Scientific Laboratory and the
nature of their work in that era makes it almost certain that this particular device was a part of a system measuring radioactive particles
originating from nuclear blasts. Neat!
There isn't that much literature I can find at a glance on the Rich 100. One nugget:
| Quote: | | "General Electric marketed several commercial models of their automatic CNCs; the first of these “continuous condensation nuclei counters” was
described by Skala (1963). When Ted Rich, George Skala, and others left General Electric to form Environment/One, a new series of continuous flow
photoelectric instruments was developed. The first of these was the Rich 100, which came on the market in 1973. An updated version of this instrument,
the Rich 200, is still on the market." [2] |
Absolute counts aren't that important to me... just relative. So calibration or cross-calibration as others have done with multiple CNC/other devices
isn't necessary for me (I guess there could be some drift over all these decades which would call for calibration via aerosol generation... I don't
know).
I hope to eventually set up an apparatus similar to [3], but with just the condensation nuclei counter.
I expect to replace all the capacitors, test the resistors, diodes, etc, before I dare consider turning it on. A humidifier is an essential component
of a CNC, so there may be water damage in places. Some petroleum based foam parts (vibration cushions) appear to have substantially decayed.
I'm sure there are other devices/technologies capable of measuring what I intend, but I'm going to use what I can get my hands on for as cheap as
possible.
[2] Peter H. McMurry (2000) The History of Condensation Nucleus Counters, Aerosol Science & Technology, 33:4, 297-322, DOI:
10.1080/02786820050121512
[3] Górny, R. L., et al. (2002). Fungal Fragments as Indoor Air Biocontaminants. Applied and Environmental Microbiology, 68(7), 3522–3531. http://doi.org/10.1128/AEM.68.7.3522-3531.2002
    
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