All TANITA body composition monitors use advanced Bioelectric Impedance Analysis (BIA) technology. When you stand on a Tanita monitor, a very low, safe electrical signal is sent from four metal electrodes through your feet to your legs and abdomen.
The electrical signal passes quickly through water that is present in hydrated muscle tissue but meets resistance when it hits fat tissue. This resistance, known as impedance, is measured and input into scientifically validated Tanita equations to calculate body composition measurements. Depending on the monitor, body composition measurements are provided in under 20 seconds.
For more information about BIA technology please check link and video below: