Unfortunatly there no chance to add any wire because of structure of gage. Please see attached file .
How long are the lead wires on the gage? Do you have to lengthen those wires any more to get them to reach to the SCXI module?
If the lead wires are short, you might be able to safely ignore the length of the wires and just wire like you had in your original image. If they are too long, you might need to shorten them closer to the gage and make the connection for the 3rd wire there.
It is hard to say. You'd have to go through the calculations of a wheatstone bridge and determine if the error caused with or without, or with a variation of the 3rd wire is large enough for you to be concerned.
One other thing is that I believe the DAQmx setup for a strain gage channel allows you to enter a value for lead wire resistance, and this might allow your system to compensate for the lead wire error in software. But that input in the DAQmx channel is not something I played with much.
5m wires length. But gage not 3 wire. Gage is 2 wire x 3 channel (red,green,white).
So that length resistance not important now. The reel issue is connection.
You can wire it up like you had in your original handdrawn diagram.
You can add a third wire and have it connect really close to the gage if you carefully strip off the insulation on one of the leads and solder your new 3rd wire in at that point.
You can cutoff most of that wire, and solder it back on to the very short lead you have left with the new 3rd wire.
Unfortunately i can't add any new wire to gage because of it's submersible gage.
So that, another solution must be found how i can connect the 2 - wire gage to SCXI-1520 module.
What you should do is use the quarter bridge II configuration like shown on page 2-3 of http://www.ni.com/pdf/manuals/372583e.pdf. This uses an extra gage intended for thermal compensation. But since it also has the lead wires, it would compensate for that as well.