Bone density tester is a testing instrument to measure the mineral density of human bones and obtain various related data. Bone density is an important symbol of bone quality, which can reflect the degree of osteoporosis and predict the risk of fracture. At present, the common bone density testers on the market are divided into two categories: X-ray bone densitometer and ultrasonic bone densitometer, of which X-ray bone densitometer has the difference between dual-energy and non-dual-energy, the mainstream is still dual-energy bone densitometer, through a special device to obtain two kinds of low-energy and high-energy photon peaks, these two kinds of photon peaks through the human body is received by the instrument, and then through computer data processing, the mineral content of bone, can check the body The amount of bone in any part of the body is highly accurate and less harmful to the human body. The amount of radiation for checking one part is about 1/30 of taking a chest X-ray, and its detection parameters are mainly T-value and Z-value. Ultrasonic bone densitometer emits ultrasonic waves from one side of the bone to the other side, receives the ultrasonic waves through the body through the instrument, and calculates the density and strength of bone tissue and other data respectively, and its measurement parameters are ultrasonic sound speed and ultrasonic frequency attenuation.