Volltext: Reports of Visits to Foreign Laboratories, vol. 7 (1932-33) [Illustrated Typoscript in 7 volumes] Reproduced with the kind permission of Dr. Cecil E. Leith (7)

Two forms of apparatus of interest to the Laboratory are 
furnished. One is the rotamesser and the other the rotaregulator. 
Of these the first is calibrated. For example, the weight of the 
little hard rubber float is known to one-tenth of a milligram and 
its diameter known to a fraction of a millimeter. This brought up 
the discussion with Mr. Meyer as to why they charged the Nutrition 
Laboratory five dollars for one of these floats that would not 
weigh any more than a diamond that would cost five dollars. It seems 
we ordered a float to replace one that had been broken, and Mr. Meyer 
states that we ordered a float for the rotamesser and they assumed 
we wished a float the exact duplicate of that broken, assuming it 
was to be used with a perfectly calibrated tube and hence to use 
the old calibrations the float must be the "exact counterpart”. This 
called for a great deal of precision work. For example, Mr. Meyer 
had them bring out the time card of many months ago of the workman 
on this particular float and we found he had spent three and one-half 
hours on it. Mr. Meyer maintained that if we had wished a float of 
only "approximately" that size it could have been made up and sold 
to us for one dollar. It was stupid of us not to have ordered more 
specifically, for we did not have the rotamesser but simply a 
rotaregulator, the difference being that the first is calibrated and 
the second is not calibrated. Thus, a small difference in the weight 
of the float would be no damage to us as we must calibrate anyway. 
Finally I had this all successfully ironed out. He said he would be 
glad to furnish people with rotaregulators at ten dollars and an 
extra float at one dollar. This means of course that they must be 
subsequently calibrated. 
After clearing up this matter of the rotamesser we went over the 
factory, but I was disappointed that I could not see the rotamesser 
mandrel or the tubes or the process of fusing. The mandrels, he 
stated, are made by one firm in Europe, the only one who can grind 
them closely enough. This word "grind" implies something more than 
the acid treatment but seemed to be a secret, so I could ask no 
questions about it. The glass tubes for the rotamesser are not made 
in Aachen. I came to the conclusion that the rotamesser is of the 
same precision as a chemical balance and should be judged by that and 
not as 6 pennyworth of glass tubing. They also manufacture ampoules, 
test tubes, syringes, etc., with a most interesting automatic machine. 
It really was worth the trip to meet this man, an ingenious engineer 
and designer.


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