Theoretical question, i cant find the answer to this.

Im running a compressor to an air tank that has to be filled to a certain PSI. Due to the close range of switche operation, and the fact i wasnt able to find one with manual override, i will be running manual switch with apressure gauge to the interior. I dont want the compressor to run all the time.

I need to be able to record minimum of 150 psi. The gauge is no issue, only problem is, i dont want a mechanical one, as the thought of 150 psi running through your interior is worrying. So ive opted for an electrical gauge.

Question is, i dont know if anyone has a pressure gauge (specifically the sender) made specifically for air. The ones im finding are mostly for oil pressure.

Will the reading be off if air pressure is measured with a liquid pressure sender? ie: since air is compressible, will it skew the readings? Thanks.

Im thinking of running a 150 psi oil pressure sender to accomplish this. If someone has a source that sells actual electrical air pressure gauges , please let me know.

 

Look at gauges for measuring natural gas pressures. Those are common, and easily available in Canada (Calgary).

I'm holding a pressure sensor in my hand that sends out a digital signal, 4-20mA.
The oil pressure sensor and intake manifold pressure sensors are different, so you may be on to something re gas vs liquid.

 

It won't make any difference if it's for oil or air.

Why do you need such high air pressure?

 

Current-loop is analog, grasshopper.

 

oh tell me it's for a shifter or something cool!

Ashcroft
Fisher
WIKA

are three companies that come to mind.
This one might work;
http://www.ashcroft.com/products.cfm?doc_id=258
Just a sender and switch, saves you having to read a gauge and flip the switch yourself.


Oh your freakin' electrical guys, always on my case about the semantics...

 

That piece is just a switch, not a gauge sender. Be prepared for sticker-shock, too.

Do you really need 150+ PSI?

 

Yea, I figured if the switch had the right range (since that one was adjustable), then he could skip the gauge altogether. Unnecessary gauges are for Hondas

Bah, stuff in the oil industry is cheap. hahahahahahaha.

Now, inquiring minds want to know, wha's it for??

 

Damn, i always do this. Explain EVERYTHING In detail, and leave out the main part.

Its for a horn. Mine was dieing, and ppl can be ****** in rush hour, so a nice loud horn is handy sometimes . Yes i need 150 psi. Its full operating capacity. It will honk upwards of about 10ish psi, but ofcourse not at full capacity.

Apeiron, are you speaking from experience when u say oil or air wont matter?

 

Usually the only difference in pressure senders is the material used for the seals or diaphragm. Air can use anything, oil needs fluoroelastomer seals that don't dissolve in oil, corrosive liquids need teflon seals, pure oxygen needs seals that don't spontaneously combust, etc.

You might find this project is more trouble than it's worth. Have you priced out an air compressor that will deliver more than 150 psi on a car's 13.8v power? If you really need to be that annoying, you'd be better off using a tank of compressed gas.

 

There’s lot’s of ways to make 150psi in a car… to start with a lot of the little portable 12v compressors will do it, and I’ve considered rigging an AC compressor to do onboard air on my truck for air tools.

As far as controlling this, ever consider a normal compressor switch? It will turn on and off usually with something like a 30psi pressure differential, but something 120psi on and 150 off should be close enough. They are usually available for $20-30 on ebay.

 

hahah, that's terrible!!!! Whats wrong with another normal factory style (non compressed air) style horn? I mean, is this like a Kenworth style horn or what? No one will be expecting that from a Camaro, that's for sure. Shock value should be fun.

 

Actually, another thought, as far as using an air horn in a car, there's a number of compressor setups just for that, even tankless ones and cheap. Try JC Whitney

As far as why/being annoying… try living someplace like the DC metro area, where traffic is awful and people are worse. I’ve considered a train horn on my truck more than once to properly scare the **** out of some ******* that desperately deserves it.

 

Actually, i bought the compressor and horn, with wiring. Its a kit. The only thing not included is the switch. So ill tell you about that in a minute. The rest is all hooked up and working great.

Thats right, however, i have the compressor and horn, so why bother right? As for a simple switch, yes i have considered it. $15 at a parts store near me. However, i dont want my compressor running all the time. If you can picture it, it will work something like this:

Wire the switch to an ignition switch. (so it only operates when key is on).
Turns on at say 110psi, and off at say 150psi.

So it charges up. You use the horn through the day. The psi is now 111, and you park the car. Over night because of the cold, your pressure drops slightly, you turn on the key, compressor goes on, and its just alot of load being used.

As well a couple of horn blows might bring the pressure down. I just dont like the idea of it running all the time. I would like to be able to control that.

Just personal preference i guess. But im just after the switch, only thing not included in the kit.

Whats wrong with a factory 305? Nothing i guess, but a 454 is just so much better

Yea its a good thing i dont live in a place like that. But i mean im not using this horn ALL the time, but it would be nice to have after not having a horn for a long time. Good for the long highways at night to avoid deer too.

I beleive this one is rated at 159 decibals? (hope i spelled that right)