How to calculate yield load from this graph

[nizars]

How calculate yield load from this graph..pls tell..

 

[Dnyan Deshmukh]

Yield Load is, When at first the elongation in bar occurs without getting increase in the applied load on test specimen.

In this case yield load is around 180 Kn

 

[nizars]

Sir, obove graph at a particular load get at zero displacement.
Actually tensile testing graph starting from zero load at zero displacement.then yield value should be below 180 kn?