Fluke RUSKA 2413, Руководство пользователя

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RUSKA 2413, 2417 & 2416
Users Manual
3-2
is no valve on the line to the cell, the line must be temporarily disconnected and stopped
off. The valve to the liquid supply reservoir is opened and the plunger advanced
somewhat to remove the backlash in the pump spindle nut. With the reservoir valve
closed, the screw crank is slowly rotated until the Bourdon gage pointer is observed to
move a perceptible amount. The quantity of motion of the screw is noted. The motion of
the crank should be small — something like one-quarter turn or less. After reattaching the
differential transducer to the system and pressurizing the opposite cavity to several
hundred psi, the experiment with the screw pump is repeated. The difference in rotation
of the screw crank in the two experiments represents the quantity of air remaining in the
cell. In these experiments, the gage pointer must not be resting against a pin at zero
pressure. It is obvious that pressurizing the opposite cavity will prevent the flexible
diaphragm from spoiling the experiment. It is not difficult to keep the free air in the
differential pressure transducer below 0.05 cc.
Bleeding Lower Chamber in a Liquid-To-Liquid System
When charging the small cavity beneath the diaphragm, a bias pressure is placed in the
upper cavity to force the diaphragm against the lower cavity surface. After the plug
beneath the cell is loosened, some liquid is forced into the lower fitting until the liquid
appears around the plug threads. This method is adequate in most instances. A small
bubble is trapped in the vertical section of the input port to the lower cavity; but after
pressurizing the liquid for a period and repeating the process, the bubble is mostly
displaced or dissolved. For more thorough displacement of the air, the cell should be
inverted.