Hi Everyone,
I am trying to sinter some copper ink using a solder reflow oven.  To prevent oxidation of the copper as the temperature is elevated, I'd like to purge the system with nitrogen to displace the oxygen before the temp is ramped (the oven allows me to do this).  I'm unsure, however, what the exact requirement is - for 'oxygen-free' processes, what level of O2 is typically allowed? How is it measured?  From what I've seen, there are basically two types of O2 sensors - relatively inexpensive ones designed for determining whether an atmosphere is breathable, or those with ppm accuracy.  The former may not be sensitive enough, the latter are horribly expensive and not particularly well suited to being placed inside a reflow oven.  What is commonly used in the industry?  Any advice or recommendations would be greatly appreciated.

regards,
Rob