Continued studies of calorimeter performance at the Lawrence Livermore Laboratory

Calibrations of two calorimeters used for tritium and plutonium assays were made. Data from three new standards of about 0.5, 1, and 5 W were added to the results of a previous report and analyzed together. The accuracies of both calorimeters appear to fall within the specified 0.5 percent, although the data now available for the large calorimeter is insufficient to permit a more definite conclusion. An expression of the bias correction for each calorimeter with respect to the sample power cannot be determined. The bias of the medium thermopile-type calorimeter tends to be positive, however, and that of the large resistance-bridge design appears to be negative. (auth