With all due respect there are several things to consider when "testing" the weight and so forth. Each individuals genetic makeup ,body temperture,placement of patch,meds,diet,exercise etc can make it almost impossible to measure how much a patch weighs or more importantly how much fentanyl is being introduced over a specific time.
The fact is that if you average it out it delivers 25,50,75 or in my case 100mch an hour over a 72 hr period, I will have to research this more though and get back with you. sincerely DTRB