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AD-4407A Weighing Indicator
3.3.
Adjustment of the Load Cell Output
Caution When adding a resistor to adjust a load cell output, use a metal film
resistor in the range of 50kohm to 500kohm with a good temperature
coefficient. Use as large of a resistance value as possible in the
range in which the zero adjustment is possible. Solder this resistor
at a point near the load cell or the indicator.
In Case of Reducing the Output Voltage
When the zero output is too large, add a
resistor between EXC+ and SIG-.
In Case of Adding an Offset Voltage to the Output
When the zero output is too small, add a
resistor between EXC+ and SIG+.
3.4.
Verifying Load Cell Output and Input Sensitivity
The input sensitivity of the indicator is 0.15
µ
V/division or more. Satisfy the following
inequality, when you design a weighing instrument using the indicator and load cell(s).
Caution A change in input voltage sensitivity is required to cause a one
division change of the display. Select as large an input sensitivity
voltage as possible so that the weighing interval becomes stable.
Consider the leverage if a lever is used.
Weighing instrument
using one load cell.
A: Rated capacity of load cell [kg]
B: Rated output [mV/V]
D: Weighing interval [kg]
E: Excitation voltage [mV]
N: Number of load cells
Weighing instrument
using multi-load cell
Verification Example
Design:
Load cell
N=1
Rated capacity
A=750 [kg]
Rated output
B=3 [mV/V]
Excitation voltage E=5000 [mV]
Weighing interval
D=0.05 [kg]
Weighing capacity
300 [kg]
Therefore, regard the instrument as a
good design.
3. Installation and Precautions
Loadcell
Additional
resistor
Loadcell
Additional
resistor
A
D
B
E
15
.
0
∗
∗
≤
N
A
D
B
E
15
.
0
∗
∗
∗
≤
15
.
0
1
750
05
.
0
3
5000
≥
=
∗
∗
Содержание AD-4407A
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