We have two ways to do this. The first is to have a group of 6 bottles sent over when new chemistry is installed in the machine. What we would like to happen is to take samples of the chemistry in the machine every 2 weeks or 50 pump hours. Once this time has been completed, send all the bottles to our lab in Nashville, Tennessee. At that point, our lab will determine all the information discussed for all the samples and see what is happening to the material in your specific application. The second thing we will ask is for a sample to be pulled at the point the cleaning starts to not be as effective. We can then glean what the NVR is and use this as the standard time of replacement going forward, bringing it back approx. 10% to protect the envelope of useful chemistry.