For sample extraction, there are two ways to proceed - all require opening the carboy. 

 

There is a device called the "Wine Thief" that works well.  It is a plastic tube with a one way check valve at the bottom.  It fits through the carboy neck and allows a small sample to be quickly removed.  It is clear and black plastic.  I am not sure if there are any metal parts on the valve.  One of the nice features is the ability to touch the plastic needle valve on a cylinder allowing the liquid to be dispensed for your test.  The other nice thing is the remaining liquid can be dumped into a glass for further testing. 

 

Most wine and beer shops carry them. 

 

Other location is the scientific supply company in St. Paul.  It is a real "dangerous" spot to visit especially with cash!  They are located on the north side University Avenue just on the St. Paul side of 280.  Sorry but I don't have their address or name but the last name is "scientific."  They have Pipettes, microscopes, test tubes, glass tubing, earlymeyer, beaker...........  Like I mentioned, really dangerous to the budget. 

 

Best of luck. 

 

Rick Oftel