Mantracourt Electronics Limited
SGA/A & SGA/D User Manual
12
Table 3.9
SW2
1
2
3
4
5
6
7
8
%
+ ve Offset
- ve Offset
40%
20%
10%
5%
2%
1%
Example :-
An installation has a tare of 15 kg with a 200kg strain gauge which gives an output of 6.37mV/V at 10V excitation.
The tare equates to 7.5% (15/200). Set the switches to nearest % (5 + 2) and fine trim with Potentiometer P2.
The tare must be subtracted therefore the ‘- ve Offset’ switch SW2/2 should be ‘ON’.
The calibrated zero mV reading would be 4.78 mV i.e. 7.5% of 63.7mV
Table 3.10
SW2
1 2 3 4 5 6 7 8
7.5%
0
↓
1
↑
0
↓
0
↓
0
↓
1
↑
1
↑
0
↓
SW2
tsrsssrrst
Note
SW2 /1 & 2 should never be 'ON ' together. Either one or other should be 'ON ' if an
offset is required; otherwise both switches should be 'OFF '.
Switch settings 3 to 8 are ADDITIVE. The offset value of each switch is added to give
a total offset of 78%.
Fine adjustment is provided by potentiometer P2.
