Worst customer service / lemon of an instrument I've ever worked with. The company I work for purchased a GPC MAX from Viscotek before the company was purchased by Malvern. At that time, although the machine was a total lemon, at least Viscotek had great technicians/customer service and our machine ran most of the time. Now that Malvern is responsible for the customer service I spend more time on the phone with them troubleshooting problems with the instrument than i do working with it. The have what the call a "help desk" in place but this is nothing more than a help menu on a computer in front of a company representative. When you try to explain a problem in detail, the information goes way over the head of their representative and they just ask you stupid questions like what flow rate or solvent system you are using in the machine. I have been asked more irrelevant questions in my entire life. If purchasing a gel permeation chromatography machine please look into a higher end company like Waters. They are more expensive but you get what you pay for. read more