Omron BF500 User Manual

6

What You Should Know When Using This Unit

The BF500 estimates the body fat percentage by the Bioelectrical Impedance (BI) 

method. Muscles, blood vessels and bones are body tissues with a high water content 

that conducts electricity easily. Body fat is tissue that has little electric conductivity. The 

BF500 sends an extremely weak electrical current of 50 kHz and less than 500 µA 

through your body to determine the amount of fat tissue. This weak electrical current is 

not felt while operating the BF500.
In order for the scale to determine body composition, it uses the electrical impedance, 

along with your height, weight, age and gender information to generate results based on 

OMRON’s data of body composition.

During the course of a day, the amount of water in the body tends to gradually shift to 

the lower limbs. This is why there is a tendency for the legs and ankles to swell in the 

evening or at night. The ratio of water in the upper body and lower body is different in 

the morning and evening, and this means that the electrical impedance of the body also 

varies. Since the BF500 uses electrodes for both hands and feet to take measurements, 

it can reduce the influence of these fluctuations on measurement results.

Muscles, blood vessels and bones are body tissues having a high water content that 

conduct electricity easily. Body fat is tissue that has little electric conductivity. The 

BF500 sends an extremely weak electrical current of 50 kHz and less than 500 µA 

through your body to determine the amount of fat tissue. This weak electrical current is 

not felt while operating the BF500. The Bioelectrical Impedance Method safely 

combines the electric resistance with the distance of the electricity conducted. Correct 

posture and consistent measuring conditions need to be maintained for the best results.

OMRON has conducted research using exhalation and MRI analysis to develop an 

algorithm by which the bio impedance method of the BF500 works.
Body Fat Percentage: This is based on the DXA (Dual Energy X-Ray Absorptiometry) 

method, which has been the established method for accurate evaluation of body 

composition. OMRON has used research information from several hundred people 

using the DXA method to develop the formula by which the BF500 works. The body fat 

mass and body fat percentage is calculated by a formula that includes five factors: 

electric resistance, height, weight, age and gender.
The DXA method uses two different frequency X-Rays and rates of absorption of the 

body and determines the value based on the difference between the two.
Resting Metabolism: This is based on exhalation analysis, where the composition of 

exhaled air is analysed. This makes it possible to calculate the resting metabolism by 

measuring the consumption of oxygen in exhaled air.
Visceral Fat Level: This is based on MRI (Magnetic Resonance Imaging) analysis, 

which uses nuclear magnetic resonance that take non-intrusive images of the body. This 

makes it possible to calculate the area of visceral fat in the body.

HBF500-E.book  Page 6  Friday, October 24, 2008  10:41 AM