Toshiba Density (Consistency) Meter LQ500, Руководство по эксплуатации

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9.3 Phase Angle Rotation Correction (Details)
This section describes the special setups and actions required for cases of measuring high density.
In normal measurement, it is unnecessary to be aware of the phase angle rotation correction, which
is performed automatically.
9.3.1 Care point concerning phase angle rotation
As described in 9.2.1, the number of phase angle rotations N is incremented or decreased judging
from the values before and after the measured value. Such a processing requires the condition that
the measured phase value varies continuously in accordance with the density of the measured
matter. If the density meter detector is empty, however, the continuity of measured phase values is
damaged thus making a normal phase angle rotation correction impossible, which in turn may cause
the number of phase angle rotations to jump to a faulty value. If the number of phase angle rotations
N is inappropriate, the density calculation result will also turn out to be erroneous. Once such a
trouble occurs, it is necessary to reset the number of phase angle rotations N to an appropriate
value through manual input.
9.3.2 Phase angle rotation in external synchronized operation
The trouble previously described will be solved by performing the "external synchronized
operation" incorporated into this density meter. In the external synchronized operation, if the
contact signal is switched OFF synchronized with the pump shutdown, not only the output is
switched to the simulated one but also the immediately preceding value is kept as the number of
phase angle rotations N.
9.3.3 Outline of automatic adjustment function of phase angle rotations
Furthermore, this density meter is equipped with the function of "automatic adjustment of phase
angle rotations." This function judges whether the measured density calculated with the number of
phase angle rotations N is proper or not in terms of the set density measurement range, etc. and
then adjusts the number of phase angle rotations either incrementally or decreasingly if necessary.
Even when the density meter detector is temporarily made empty thus causing the number of phase
angle rotations N to jump to an inappropriate value, this function is also used to fill up the density
meter detector once again with the matter to be measured and automatically adjust the number of
phase angle rotations N to an appropriate value, which in turn will render an appropriate value for
the measured density. While the density meter detector is left empty, the measured phase value
itself comes to have an indefinite value, which in turn will render the measured density indefinite.
Therefore, if the density meter detector could be made empty, it is desirable to perform the external
synchronized operation.
9.3.4 Judgment conditions and adjustments for automatic adjustment of phase angle
rotations
The judgment conditions and adjustments regarding the automatic adjustment of phase angle
rotations and the measured density are listed in Table 9.3.1.
Table 9.3.1 Judgment Conditions and Adjustments
for Automatic Adjustment of Phase Angle Rotations
Measured Density Automatic Adjustment of Phase Angle Rotations N
X
min
= Less than
−
4(%TS) Incremented (N = N+1)
−
4
〜
C
×
a
×
360(%TS) Unadjusted
X
max
= More than C x a x 360 (%TS) Decreased (N = N-1)