The machine adopts magnetic suspension principle and uses the electromagnetic motion when rising in testing the key-press.while falling,it adopts the magnetic force as the key-press pressure for exact adjustment, so that it eliminates the influence of increasing the pressure measured value because of the acceleration by self-weight inertia and motion work,reflecting the real lifetime of tested product truly. This machine uses aluminum alloy tank bracket glass for workplace,looking laconic in the QC section, (we can supply dial gauge).