Total body potassium calibrations for normal and obese subjects in two types of whole body counter

The 42K technique has been used to calibrate two dissimilar whole-body counters (liquid scintillator and NaI) for total body content of potassium (TBK) measurements over a wide range of body weight (50.6-119.1 Kg). The standard error of an estimate of a TBK of 140 g is in the range of 3.0 to 3.4% for both counters and is similar to values reported for other counters (Burkinshaw (1967), Body et al. (1971), Hawkins et al. (1976)).