An improved continuous ether extractor is described. The modifications include a means of safely disposing of the active raffinate and a means of positivity checking the raffinate for completeness of uranium extraction. The results obtained on synthetic samples and on dissolver solutions are given. This work was undertaken because of a need for the determination of uranium in dissolver solutions with an accuracy of 0.1 per cent. After a review of available methods it was decided that a gravimetric determination would meet the requirements of precision and accuracy.