distance sensor for bending tester

I am setting up a 4 point bending tester. It is run by a 2 phase stepper motor (Vexta pk266ma) and a 2 phase stepper driver (Vexta udk2120a). The motor drives a set of spurs gears which in turn drive 2 worm gears which in turn drives 2 power screws to raise and lower the platform. I have the motor turning in steps with an Arduino program.

I need help figuring out what sensing device to measure the distance of the moving platform from the base of the tester(or a home position). The sensor needs to have a fairly high accuracy because it's measuring strain from deflection. Also, I will be using LabVIEW eventually for DAQ and possibly using LabVIEW to fully run the tester or assist Arduino in running it.

Sorry if I am missing any pertinent information, I am fairly new to this.

Thanks! Zach

Can't you work out how far the platform has moved from the number of motor steps and the gear ratios?

How are you measuring the force applied?

As Archibald said, if you can ignore slip or strain in the mechanics, you can get position from motor steps.

Otherwise, you might use a linear encoder.

Google "linear displacement"