COND SGA-A & SGA-D Manuel_EN Rev3.doc
Page 10 on 20
Rev: 03/08/2006
3.4.2.
Example : A strain gauge has a sensitivity of 2.809 mV /V
Select Switch Setting number 28 from Table 3.6 and fine tune with potentiometer PI
SW1
1 2 3 4 5 6 7 8
2.63 mV/V
0
↓
1
↑
1
↑
0
↓
0
↓
0
↓
0
↓
x
Table 3.7.
Refer to Chapter 4 for calibration details.
3.5.
Shunt Calibration Switch SW1/8
SW1/8 connects a 120k 50ppm surface mount resistor across the ‘+Excitation’ and ‘+ Input’ terminals of the
COND SGA. This shunts one arm of the connected load cell to produce a known change in output which can
be used for calibration or checking the integrity of the load cell and associated wiring.
SW1
1 2 3 4 5 6 7 8
Shunt
Cal
ON x x x x x x x 1
↑
Shunt
Cal
OFF x x x x x x x 0
↓
Table 1.8.
The 120k resistor can be taken out of circuit and replaced by a user defined leaded component by carefully
cutting the fine link as shown in Figure 3.3. Use the right hand pad and either of the left hand pads to fit the
new component.
The surface mount resistor can be reinstated by re-connecting the two pads either side of the cut link.
Figure 3.3.
3.6.
Zero (Offset) Setting Switch SW2
This offset can be used to compensate for the transducer zero error, to tare the scale dead load or to shift the
output. These settings allow the user to calibrate a zero offset. The range allows for up to 79% of the span.
Potentiometer P2 provides fine adjustment.
SW2
1 2 3 4 5 6 7 8
%
+ ve Offset - ve Offset
40%
20%
10%
5%
2%
1%
Table 3.9.
SW1
