vacuum gauge location

I was wondering if anyone can answer a question about my homemade pumping tube. Specifically I need to know where to place my vacuum guage. I have a homemade tube that gets great vacuum. Today I bought a small vacuum gauge, drilled a hole in the top of my cylinder, and screwed the gauge into it. Now I still have great vacuum, but the gauge registers nothing on it.

I hooked a tube to the gauge to test it. If I suck on the tube, the gauge goes in reverse to the negative hg range. When I blow the gauge goes to the positive range.

My question is: Does the gauge have to be integrated into the suck mechanism I have (no pump, just a suck tube), or should it be able to pick up vacuum as long as its attached to the tube.

Sorry if I’m being vague, I’m new to pumping.

I think you will have to make sure it in the outflow of air from the tube. But you must also have some sort of stop to allow the vacuum to be registered. so that the entry into the vacuum gauge is cut off from the outside air Difficult to explain without a diagram but it can be likened to the valve on a bicycle tyre that only allows flow in one direction

Thanks for the reply petitfaun. I guess I’m going to be re-arranging my pump setup a bit.