Abstract: "Hexavalent uranium in weakly acid solution produces with a large excess of ascorbic acid a yellow-brown color whose intensity under certain conditions is a linear function of uranium concentration. Chloride, nitrate, perchlorate, along with Fe, Cd, Mn, Na, Ca, Sn, Mg and Th are without effect on the color while phosphate, sulfate, fluoride, citrate, tartrate, oxalate, chromium, and vanadium and moderate amounts of Ni, Zn, Mo and Al interfere. A rapid ether extraction procedure for purification of the uranium has been developed."

Abstract: This technical report consists of series of drawings of the instrument with the following explanation. The modification of the Simpson Methane flow proportional counter consists of a means for inserting and replacing samples into the chamber through an air-lock device which avoids the introduction of even a small quantity of air into the active volume of the chamber. This is accompanied by sweeping out the small volume of the air-lock containing the sample with methane gas before the sample is introduced into the chamber -- this sweeping out requiring only a few seconds. The mechanical construction is somewhat simplified over that employed in the Simpson counter design, although the electrical and counting characteristics are essentially duplicates of those employed in the Simpson version. Voltage plateaus about 400 volts long, flat within 1% per 100 volts are obtained with the counter, with the operating point at about 2500 volts for methane at one atmosphere pressure. A plateau extending over a range of about 40% variation in amplification factor is obtained. Standard samples have been checked to standard deviation of +/-0.3% over a period of one year. The counter is rather gas-tight and is ready for use within about ten minutes …