Aluminum planchet counting: a simple method for improved sample spreading

Uniformity of spreading is much improved when a drop of ammonia is added to aluminum planchets before drying the sample. The method makes special drying equipment unnecessary, but is applicable only to aluminum planchets. Data employing other spreading agents are also presented. A statistical analysis is given for all of the data and several different procedures could be derived from these data depending on the needs of the user.