to use the  traditional test method of  OH value to determine the samples taken in polymerization process for preparing the standard samples. 

But apart from OH end group rest of the molecule matrix always get change in our sample so NIR calib curve is strictly OH+Matrix of entire polymer chain depedent, so how we can overcome this problem. 

But apart from OH end group rest of the molecule matrix always get change in our sample so NIR calib curve is strictly OH+Matrix of entire polymer chain depedent, so how we can overcome this problem.