I just installed a Barometric damper on my flue of my Caddy. I know I am suposed to have .04-.06" WC. But how do I test it? I talked to a HVAC guy tonight and he was scratching his head on how he would take the reading. I do have a meter that reads WC in .01 incraments, but I am scratching my head on how to get a reading from my stove.