Azbil Corporation
28
Model
KFPA
,
KFTA
- Field Mount type Pressure Indicating Controllers
5-3: Adjustment of set point indication
Calibrate the set point indication by connecting an input (20 to 100 kPa {0.2 to 1.0
kgf/cm²}pressure) to the ESP connection port of the instrument.
(1) Zero adjustment
Turn the zero adjusting knob of the travel link so that when the input is 0%, the
measuring pointer points at 0. The pointer falls as the knob is turned clockwise as
viewed from the bottom of the instrument.
(2) Span adjustment
Turn the span adjusting screw so that when 80% input is applied, the PV pointer
indicates 80%. As the screw is turned clockwise, the span increases.
If a large change in the span is necessary, change the position of connection of the
travel link and the hole of the span adjusting screw. As the connection position is
set farther from the center of the element, the span becomes larger.
(3) Linearity adjustment
(a) Check the linearity at the 50% scale point.
(b) If an error larger than 1% F.S. is detected, change the travel link length by
turning the adjusting knob. If the error is plus with respect to the scale, make
the travel link shorter (turn counterclockwise as viewed from the bottom).
(c) A change in the travel link length will cause a shift of zero point. So, loosen the
zero adjusting screw, align the pointer to the scale and then fasten the screw.
(d) Check again the zero and span in the method mentioned before.
Figure 25
90
90
SP setting knob
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)
