Azbil KFDB, Руководство пользователя

Страница: 25 / 48

21
(2) Adjust so that the total weight (W) becomes the same with the weight of the float (3 kg for
medium specific-gravity measurement or 4.5 kg for low specific-gravity measurement).
(W = Calibration Pan Dummy weight)
(3) Apply to the pan a weight corresponding to 100 % of the measuring range.
(4) If the output pressure is largely shifted from 100 % (100 kPa {1.0 kgf/cm
2
}), adjust the
SPAN CHANGE boss using a plain screwdriver so that the output pressure becomes
approximately 100 %. As you turn the boss clockwise, the output pressure rises and the
span becomes narrower. As you turn the boss counterclockwise, the output pressure falls
and the span becomes wider.
(5) Apply to the pan a weight corresponding to 0 % of the measuring range.
(6) If the output pressure is shifted from 0 % (20 kPa {0.2 kgf/cm
2
}), adjust the ZERO ADJ
screw so that the output pressure becomes 0 %. As you turn the screw clockwise, the
output pressure rises, and vice versa.
(7) Apply to the pan a weight corresponding to 100 % of the measuring range.
(8) If the output pressure is shifted from 100 %, adjust the SPAN ADJ boss at the bottom of
the feedback bellows as follows:
If the output is higher than 100 %, turn the boss so that the output becomes lower than
100 % by an amount of 1/4 of the shift. (For example, if the output is 104 %, turn the boss
so that the output becomes 100 − 1/4 × 4 = 99 (%)).
If the output is lower than 100 %, turn the boss so that the output becomes higher than
100 % by an amount of 1/4 of the shift. For example, if the output is 98 %, turn the boss so
that the output becomes 100 + 1/4 × 2 = 100.5 (%).
The span can be adjusted also by turning the feedback bellows by inserting a pin in the
SPAN ADJ PIN HOLE instead of adjusting the SPAN ADJ boss. As you turn the feedback
bellows, the span changes as follows:
Clockwise turn of bellows: Output increases (Span becomes wider.)
Counterclockwise turn of bellows: Output decreases. (Span becomes narrower.)
(9) Repeat the procedures of (6) − (8) until the required accuracy is attained.
Note: For specific-gravity change, ZERO and SPAN adjustment, refer to Chapter 2 and
Chapter 3. Specific-gravity change is corresponding to SPAN change in such
sections.
4-5-2. Calibration Procedure for Boundary Liquid Level Transmission
(1) This procedure is identical with that for liquid level transmission, except that the
following formulas should be used:
(a) Total weight W including the two weights, pan and others:
W = (Weight of float) −
π
·D
2
·L·
ρ
1 4
where, ρ
1
: Density of upper liquid
(b) Calibration weight (F) corresponding to buoyancy:
F =
π
·D
2
·H( ρ
2
− ρ
1
)
4
1+ α · π ·D
2
( ρ
2
− ρ
1
)
where, ρ
2
: Density of lower liquid