Yantrika DWT 300, Инструкция по эксплуатации

Страница: 7 / 11

"Process Instruments and Calibrators"
4.1
5.1
5.2
5.3
Closing Up
The tester should be left in the following condition after current calibration work is over.
a) Release valve: Open
b) Screw pump: Fully withdrawn by turning it counter-clockwise.
c) Union connectors: Plugged
d) Weights: Removed from the carriers, properly cleaned with a soft cloth, and stacked near the machine.
e) Dust cover: Placed over the instrument.
Re-Adjustment of Pressure Gauges
Study the test results of the pressure gauge and resolve the error at each point so as to find the zero error and
the continuous increase/decrease of error. Install the pressure gauge on the tester and proceed as follows.
Zero Error ( Constant error at all readings)
Install the pressure gauge on the tester and raise the pressure upto the value of the first main division of the
pressure gauge. Remove the pointer by means of the pointer puller and place it at the correct position by hand.
Finally fix it in position by means of the pointer punch which may be tapped by the handle of a screw driver or
a very light hammer. Check readings once again.
Study the test results of the pressure gauge and resolve the error at each point so as to find the zero error and
the continuous increase/decrease of error. Install the pressure gauge on the tester and proceed as follows.
Note: Zero error is not corrected at the zero point of the gauge.
Ratio Error ( Error continuously increases or decreases)
There is a link which connects the free end of the bourdon tube to the arm of the segment gear. The segment
gear arm has a slot in which the link is connected. Moving the position of the link in the slot towards the
bearing pin of the segment gear will cause the gauge pointer to move faster with increasing pressure. Moving
the link away from the bearing pin will make the pointer move slower with increasing pressure. This
adjustment is a trial and error procedure, but with a little practice, it may be done quite quickly. Some high
quality gauges like test gauges have another link between the segment gear and the bourdon for adjusting
linearity and angularity. This may be used to adjust the reading at mid scale.
Transmitters and digital gauges should be adjusted as per the procedure given by their manufacturer.
Instruction Manual