Document reLZzae3dXG90nZbQ9XG0M0j0

October L I;bO hr, ? : '.ciidson General 'ileotrLc .ornpany ;. r -r o h lab or at o ry I fiver i-oc.ci fohcnectady, :T. T. fear hr. cods on: I an ir.ufih .interested in your letter of ^etcher 11* T.x q range* of concentration of lead* i \ir in which we are in terested is 1 in 10W to 1 in IQ7 by voiuae, which is aoproxinatoly C001 of the concentration yon obtain now for 1/4 of the souls* If you feol that this different range could bo cover ed equally wall, this would bosons quite interesting* I presun that the method would consist in decreasing tha source of radiation and increasing the sensitivity of -the absorption measure.cert* There still regains the disturbing factor of the residual reading, ihis waght conceivably be less noticeable at the lower concentrations, but I doubt whether it would bo eliminated, since it is a v.e] 1 kr.ora characteristic of orrono-aetallio oompounds that they are decomposed by strong light* Possibly the equipment could be so designed, as to be easy to clean* I '-ill be much- interested in your comments regarding the possibility of shifting the rang of the instrument to that indicated above. If this does not lock too hopeless, I think it would bo well worth while to push the experiment a little further# ary truly yours. GTj AUC cc: IT. '",f.;Iachlo l orgo Calingaert / K 0022878