How do i measure vacuum (DIY gauge)

How i have build a , for me, good working vacuum indicator.
Can be used to measure pressure diff over filters as well.
Pictured here is range to 6" , you can find longer tubes easy.
Those pipet tubes i used cost about 0.5$ a piece


Ha! Ha! Yes 100% reliable used in conjunction with your superior intelligent data logger.
A pencil and a paper tablet. And never forget to love and respect the pencil holder.
Best Regards
Steve Unruh


Hy Koen Thanks that design looks like could be made too use as a stationary version for observation of engine working with wood.

1 Like

I hope, hear is a picture of a set up I did to demonstrate simple monometers. What you see is a tube, hooked to a shop vac on one end, a piece of tape on the other end and 2 taps on the side of the pipe. The first tap has a small clear plastic tube hooked to it and the other end goes down to the bottom of the jar ( the jar has a lid with 2 holes in it-- one for the plastic tube to go through and the other is just open to the atmosphere) This style reads “inches” on the board behind the plastic tube with “O” being the top of the water in the jar. I prefer this model for my truck (before I got commercial gages).
The second tap on the “tube” has a piece of this plastic tube attached. The tube drops down and makes a “U” and then goes back up and is left open to atmosphere. Water ( in this case coffee) is placed in the plastic tube. Again the “vacuum” is read in inches on the board behind the plastic tube. My memory is bad so feel free to correct me, but I believe the vacuum you are measuring is the difference in the height of the water in the two tubes. ( the water in one goes up and the water in the other goes down, and the vacuum is the difference in the heights of the water.) Not my favorite, but as Koen shows often used.

The above is “O” setting on both types monoters.

In this picture both are reading “9” inches of water.
I don’t have a picture of the board monometer as mounted in my truck, but I used the jar type and ran “two” plastic tube into one jar. This gave me readings from two places---- not as exact as having two jars but close enough for the girls I go with. TomC


Actually Kevin look again at WayneK’s driving vidos.
I see three of these upright acrooss the outside back of the rear window.
Center of the vehicle in the center of the wheel base has the least movements. Bus riding queasy and you’ll find that spot. Works on boats and ships too,
The actual commercial made manometers use a plug a each upright leg with a small hole in it. Dampens the movement change.
Freezing? Just plumb them to the inside of the cab. CO! CO! CO!
OK. Use alcohol and recalibrate then.


I would just use antifreeze choosing different colors, one for hopper, cooling rails, hay filter. A board on the outside of the back window. You could even write your numbers backwards on the board so they look normal in the rear view mirror.
I think I will just keep buying the $20 gauges.


Hy tom thanks for the design picture, that helped me too get the full picture . That looks like could be made too check vacuem ranges.


I agree though if i in a broke spot , i like these guys ideas even though i am hard learning new stuff. Yes anti freeze coulors would help get the job done.I will have too make a note book too memerize this type for now i got three in my top drawer still good too go. Seems the cheaper ones are gone for now, probley coved 19 slow down or the fair trade deals.


Those type of manometers are the easiest and most precise tools we can use.
I use them also to calibrate mechanical ones or electronic gauges.
Coz they give the real value in WC inches or mm


Thank you Koen. Hopefully, maybe your comment will make others understand, those other mechanical and electrical gages are just expensive devices that only add a little convenience over these.
There concerns about freezing; You do not need 100% antifreeze, just enough to stop freezing in the temperatures that are expected in the near future.alcohol or ethanol.
Sloshing in a moving vehicle; That isn’t a problem in the tubes. In the jar with liquid, use a tight lid and place a separate tube through the “vent” hole in the lid and allow to stick up a minimal amount.
Expense; You can look around for a inexpensive mechanical or electrical gage, but I guarantee you won’t find one less expensive.
Down side; You will need about a 30 inch long board/stick protruding from the vehicle floor upwards ( If leaned up against and fastened to the dash, this puts the reading area at a convenient height.) TomC


Hi, TomC, k_vanlooken
100% agree!
I use also to calibrate electronic gauges u shaped pressure gauge. Electronic devices are very suitable in everyday use.


This made me smile. I have often thought about this. Most of us look for the cheapest deal on things we buy, for instance the 20 dollar, made in china vacuum gauge, and assume we are getting an actual reading. I have seen guys build ten thousand dollar engines and then stick in cheap oil pressure or temp gauges because they came across a good deal. Not all things can be checked for correct calibration as easily as with your manometer but that alone is a big step in the right direction.