Azbil Corporation
Model
KFPA
,
KFTA
- Field Mount type Pressure Indicating Controllers
29
5-4: Transmitter unit
The transmitter unit is of a balanced displacement type. When adjusting this unit,
check at first that the measuring arm and lever are at the right angle with respect to the
travel link. If they are not set the right angle as visually inspected, perform calibration
and adjustment of the deviation generating mechanism.
Adjustment of zero and span
(a) Set the PV pointer at 0% and turn the zero (linearity) adjusting knob (A) so as to
make the transmitted pressure 19.7 kPa {148 mmHg}. The transmitted pressure
increases as this knob is turned clockwise as viewed from the case bottom.
(b) Set the PV pointer at 100%, and turn the span adjusting knob (B) so that the
transmitted pressure becomes 98.4 kPa {738 mmHg}. The span is decreased as this
knob is turned clockwise as viewed from the left side.
(c) Repeat the above procedures so that both zero point and span are correctly set.
Adjustment of linearity
(a) After adjusting the zero and the span, set the PV pointer at 50% and check that the
transmitted output is 59.1 + 0.8 kPa {433 + 6 mmHg}.
(b) If the output is less than 58.3 kPa {437 mmHg}, turn the zero (linearity) adjusting
knob (A) counterclockwise so that the transmitted output increases.
(c) If it is more than 59.9 kPa {449 mmHg}, turn the knob (A) clockwise. In this case,
about 10% F.S. movement of the zero point is needed per about 1% F.S. deviation
between the PV pointer and the transmitted pressure.
Figure 26
90
90
Coarse zero
adjusting screw
(for setting pointer)
Hole for
adjusting pin
Set point pointer
adjusting screw
SP pointer
(green)
Lever
PV pointer
(red)
Span adjusting
knob
SP base
Travel link
Zero
adjusting
knob
Zero adjusting screw
(for measuring pointer)
(A)
(B)
(C)
(D)
(E)
