Need help with FSR calculations and coding.

Projects General Guidance
1

Hi guys,
I have looked into a tutorial by ladyada @ FSR Sensor tutorial. I have a question about the calculation used in "In-depth code for analog FSR measurements" tutorial. Specially:

fsrConductance = 1000000; // we measure in micromhos so
fsrConductance /= fsrResistance;
Serial.print("Conductance in microMhos: ");
Serial.println(fsrConductance);

// Use the two FSR guide graphs to approximate the force
if (fsrConductance <= 1000) {
fsrForce = fsrConductance / 80;
Serial.print("Force in Newtons: ");
Serial.println(fsrForce);
} else {
fsrForce = fsrConductance - 1000;
fsrForce /= 30;
Serial.print("Force in Newtons: ");
Serial.println(fsrForce);
}
}

Can anyone please tell me whats happening in this calculations. I really cannot understand it.
Thanks

2

It seems to be implementing an approximation to the graphs in figs 3 and 4 of the datasheet referenced in that article...