Hughes big mouth heads

I’m going to correct you on one thing from this statement

Even the same flow bench will show different numbers on today’s hot and humid day and tomorrow’s cool and crisp day with humidity & spheric pressures differences.


An orfice style of bench is not affected by the weather like a pilot style bench. Maybe one or two CFM max. If you zero out a manometer style bench at 8am and check it at 12pm the manometer will have moved. There is even a chart that is to be used to insert the weather conditions at every lift number. This is why I got rid of that style of bench.