What should the vacuum pressure of a desoldering gun be

[Alex Eisenhut]

They really do call it a vacuum pressure. My old Hakko 707 is spec'd at 600mmHg of vacuum pressure, which means 23 inches of mercury below atmospheric of 30 inches, I guess. The newest Hakkos are rated the same. My 707 has a pump with a home-made diaphragm in there since the original part disintegrated.

http://www.hakko.com/english/products/hakko_fm204_set.html#productNav

The 707 does work, but since I finally received my eBay vacuum gauge, I jammed the tip of the iron right into the port hole of the thing and pulled the trigger. I measure about 18 inches.

Is the vacuum pressure rated right at the the pump or at the tip of the iron? And how much vacuum am I possibly losing in the tubing and the joints in general?

It's nothing major, just curious.

[Circlotron]

If the flow has stopped and there are no leaks there will be no loss of vacuum regardless of any restrictions.