Sniffer to determine the odor of gas chromatographic effluents

Althoqgh our analytical balances are maintained on a regular bask; by a service group, it is still the laboratory's responsibility to be sure that the day-to-day measurements are correct. To this end, a fast, simple way to evaluate direct reading balances has been developed. The direct reading balance has obviated the neceseity of handling weights and this improvement has unfortunately reduced the operator's awarenessi of the need for checking calibration. We have over 25 balances in our laboratory areas; and since we operate 15 remotely located service laboratories, our needs to assure uniform quality testing are especially critical. The use of National Bureau of Standards calibrated sets of weights is time consuming and the repetitive handling poses the danger of wear and damage to the calibrated reference weights. The method devised serves to check the linearity of the balance, provides a direct intercomparison with all balances, and relates all balances to a Bureau of Standards reference. This is accomplished wing the regular balance operators and results in a minimum of handling of our National Bureau of Standards reference weights. The entire operation is accomplished in a short period of time and makes no unusual demands on the laboratory staff, Three test objects were prepared by drilling out random amounts of metal from the bottoms of some old weights. These gave us a set of test objects weighing about 14, 29, and 56 g. They were carried to each balance station where an operator who normally used the balance weighed them individually and collectively. The data from each balance were recorded and no calculations made Table I. Data for 25 Balances