What the heck are you doing? ALTERNATE - Verifying Torrecelli's Experimental theory....

[Jim Pratten]

My wife asked, “What the heck are you doing?” as she took this photo.  Agree, it might look a little odd sucking on some tubing.

There was some recent forum discussion on when to change our engine air filters. Common industry recommendation is to change the filter when the restriction gauge measures 25” water column.  But how do I know my gauge is accurate?

Simple enough to test with a little tubing, some hose barb / 1/8” mnpt fittings and a bottle of water. Amazingly enough, my 24 year old Donaldson Informer gauge was darn near 100% accurate at the 10, 15, 19, 22 and 25 inch gauge indicator “trip” increments. 

[Tom Cherry]

I have NEVER tested my ANCIENT "Craftsman" Vacuum Gage (also Fuel Pressure) unit that I had back in my Hot Rodding days. I did test it when I was involved in Carburetor Manufacturing and tested a few units and we also had a QC lab that could meet FORD Q-1 Quality Standards.

I think I remember Torrecelli from Physics 208....or maybe not...

http://www.causalpatterns.org/resources/airpressure/pdfs/s1_resources_discovery_sheet.pdf

LOL.  We have some member, who will remain anonymous, that also do such....

[Jim Pratten]

32 minutes ago, Tom Cherry said:

I have NEVER tested my ANCIENT "Craftsman" Vacuum Gage (also Fuel Pressure) unit that I had back in my Hot Rodding days. I did test it when I was involved in Carburetor Manufacturing and tested a few units and we also had a QC lab that could meet FORD Q-1 Quality Standards.

I also worked at a location that had world class calibration labs and processes. You tend to get religion when your systems and tools are challenged by QC audits from folks that know the business and have the authority to red tag your equipment. 
 

 . . . and smiles Tom on the enhancement of the topic description. 

Edited February 1 by Jim Pratten