Pressure sensor for a 1/4 HP air cleaner?

[Allan Speers]

In a recent thread I got some great advice on using a magnehelic gaige for monitoring cyclone pressure at the filter.

It seems the correct range for that is in the neighborhood of 1 - 5 inches. (With some variance for total CFM)

I'm wondering what the correct range would be, to use one for a typcal shop air cleaner?
- And would it work the same? Could the sensor be anywhere between the filters and the blower assembly?

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Alternatively, Steel City used to seel a cleaner that had what appeared to be a simple "weathervane" type of indicator on the side. I assume it siply had a pivting vane inside, with the proper amout of counter weighting. Has anyone tried that instead, with good results?

[michael dilday]

My unexpert opinion it could be done. Not sure what the suction/vacuum would be. With a 1/4 HP motor probably not much. Also, I would guess you could put the sensor anywhere between the filter and the fan. Since it is not intended to be accurate but rather a reference gauge then any very minor difference caused by sensor position, if any, would be a non-factor. If you have an internal filter and a pre-filter like mine, I guess it would have to be between the internal filter and the fan. I am following this to see what your findings are. Very interesting.

[michael dilday]

I assume this is an indicator for when to change the filter. I had considered a different approach and that would be to hang something in front of the fan output that would get blown out and depending on it's angle I could determine relative air flow.

[Allan Speers]

I assume this is an indicator for when to change the filter. I had considered a different approach and that would be to hang something in front of the fan output that would get blown out and depending on it's angle I could determine relative air flow.

LOL, yeah there's always an easy way!

But, you know, I'm trying to be all scientific & stuff.
It really WOULD be good to have an actual numerical read-out, if it doesn't cost too much.
Otherwise, yeah, thin strips of crepe paper.......

[Wade Lippman]

I just put my hand in front of the output. If it feels normal, it is. Is that not reasonable?

[Bill Dufour]

I assume this is an indicator for when to change the filter. I had considered a different approach and that would be to hang something in front of the fan output that would get blown out and depending on it's angle I could determine relative air flow.

That method works well enough to earn a Noble pries. My father worked with an experimenter who had to have enough water cooling to not overheat the powerful electro magnets. With that much magnetic force gauges with moving parts or electric. signals where not accurate. The answer was a hose pointing horizontally into a sink. catch the water and calculate flow and adjust until flow was adequate but not wasteful. Then trace the flow with a line drawn on the wall to match the curve. When the cooling was needed turn on the water until it curve matched the curve on the wall and all was good.
I think excess water flow wasted energy as the minerals reduced magnetic force or something. Not much effect in our lives but when just the steering magnets needed 2000 horsepower a few percent becomes a lot. I think it was some sort of feedback loop as water flow increased more power was wasted as heat so more water had to be pumped into the cooling system which caused more waste heat needing ever more cooling flow.
Bil lD.

[Allan Speers]

I just put my hand in front of the output. If it feels normal, it is. Is that not reasonable?

No, no, no!

Must buy stuff !

Must spend money !



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Besides, you think a little crepe paper is gonna' impress Joe across the street?

[Rod Sheridan]

No, no, no!

Must buy stuff !

Must spend money !



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Besides, you think a little crepe paper is gonna' impress Joe across the street?

Make one out of a piece of clear plastic tubing bent into a U shape.

Make the U about 12" long, mount it vertically and connect one end to the area between the blower and the filter.

Fill it half way with water mixed with red food colouring.

Regards, Rod.

[Ole Anderson]

This what you are looking for? $33.82 delivered. I have one, works fine for my Oneida 2 hp SDG system. But for an air cleaner, not sure what the pressure would be. Test it with a plastic tube manometer to see if 0-5" is the right range.

https://www.ebay.com/p/Differential-...0535148&chn=ps