A&D Weighing Indicator AD-4329 - Manual (Page 8)

3.1.3. Adjustment of the Load Ceil Output
Caution a Use a inetaf film resistor in the range of 50kQ to 500kQ with a good
temperature coefficient when adding a resistor to adjust a load cell
output. Use as a large resistance value as possible in the range in which
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 S1G+.
3.1.4. Verifying Load Ceil Output and Input Sensitivity
The input sensitivity of the indicator is 0.2pV/division or more. Adapt to the following
inequality, when you design a weighing instrument using the indicator and load cell(s).
Caution □ A change in input voltage sensitivity is equivalent to a one division
change of the display. Select as large an Input voltage sensitivity voltage
as possible so that the weighing interval becomes stable,
a Consider the leverage If a lever is used.
Weighing instrument
using one load ceil.
E^tB^D
0.2 £------------
A
, Weighing Instrument
using multi-load cell
E^B h ^D
0.2^——~
A^N
A: Rated capacity of load cell [kg]
B: Rated output [mVA/]
D: Weighing interval [kg]
E: Excitation voltage [mV]
N: Number of load cells
Verification Example
Design;
Load cell
N=1
Rated capacity A=750 [kg] 6000*3*0.05 , ^
„ -j ^ 0.2. Therefore,
Rated output 8=3 [mVA/I 750
Excitation voltage E=5000 [mV] regard the instrument as a good design.
Weighing interval D=0.05 [kg]
Weighing capacity 300 [kg]
3. Insteilatìon and Precaution Page 6 AD-4329 Weighing Indicator