Abstract
While pneumatic micrometer circuits are usually treated as a first order of dynamical system, the time constant represents the dynamic performance of the circuits and varies as a function of both the operating pressure and the supply pressure. A formula of the time constant is derived in such a form that can be applied to a wide range of pressures and is graphically represented using practical size of circuit elements. Relations between the time constant and the operating pressure of pneumatic micrometers are drawn with the supply pressure as a parameter. It shows that 1) in general, the relations of the time constant to the operating pressure are shown as such curves that have a maximum value in the middle part of the operating pressure, 2) the maximum value increases until the supply pressure approaches up to about 2. 5 kgf/cm2, but beyond the value it does not change so much, 3) the time constant of the vacuum type of pneumatic micrometer is larger than that of other types of pressure. These results are in good agreement with experiment. Moreover, the effects of the repulsion force between the sensing nozzle and its counter-face on the dynamic performance are discussed.
