AB-6484
7
Figure 7. Front panel of the limiter
Ratio bias setup
How to set the ratio:
Switch the ratio/bias selector to the “RATIO” side. The ratio/bias display shows the ratio (0.10 to 4.00). Press UP/DOWN control
for the value setup.
The polarity indicator LED glows RED when the set value is in the positive gradient characteristic, and glows GREEN in the
negative gradient characteristic.
How to set the bias:
Switch the ratio/bias selector to the “BIAS” side.
The ratio/bias display shows the bias (0 to100 %). Press UP/DOWN control for the value setup. The polarity indicator LED
glows RED when the set value is positive, and glows GREEN when negative.
Figure 8. Front panel of the ratio bias
Equation:
Y = KX + B (positive gradient characteristic)
Y = KX +B + F (negative gradient characteristic)
where
Y = Output signal (%)
K = Ratio (Linear characteristics, positive gradient: 0.1 to 4.00 / negative gradient: -0.1 to -4.00)
X = Input signal (approx.-10 to +120 %)
B = Bias (-100 to +100 %)
F = 100%
Fine adjustment:
Follow the procedure below for fine adjustment.
1) Under the equation: Xo = KX + B (positive gradient) or Xo = KX + B + F (negative gradient), shift the input signal value Xi to
zero point side and adjust the output Y to the result with ZERO adjustment.
2) Shift the input signal value X to the span point side and adjust the output Y to the result with SPAN adjustment.
3) Shift again the input signal value X to zero point side and check the output Y on the zero point side.
4) If the output Y is changed, repeat the procedure 1 through 3 again for adjustment.
The unit is set and calibrated for shipment as: Ratio (K)=1, Bias (B)=0%
Polarity indicator LED
Up/down control of setpoint
Potentiometer knob for SPAN adjustment
High/low limit selector
(top: high limit, bottom: low limit)
High/low limit display
Potentiometer knob for ZERO adjustment
Polarity indicator LED
Up/down control of setpoint
Potentiometer knob for SPAN adjustment
Ratio/bias selector
(top: ratio, bottom: bias)
Ratio/bias display
Potentiometer knob for ZERO adjustment
