I know nothing about working on regs, but I was wondering what you use this device for??
A manometer or magnahelic is a pressure or vacuum gauge for measuring very small values of either pressure or vacuum. Some magnahelics are compound which means it will do both pressure and vacuum with out any valves or such. Compound means that it has a scale on it that would show positive pressure and negative pressure on it's scale (face). Some magnahelics have a zero on the left side of the face and increasing numbers going to the right , just like a typical analog voltmeter would. The way you hook your tubing up will determine if you will be doing vacuum or pressure. It has ports on the back that you either plug or utilize.
What it's used for is determining what is referred to in the industry is work of breathing , often WOB for short in magazines or technical specifications.
The magnahelic or manometer is just a way of giving that inhalation a measureable value.
How people do that at the factory , LDS, and home varies greatly.
By the way , the manometer is a very simple tube that is U shaped that has distilled water in it. The water always seeks equilibrium with itself on each leg of the U. A tube is attached to one side and either pressure or vacuum is applied. It is usually less expensive than a Magnahelic (which is a brand name). The magnahelic is usually prefered that's all.
A magnahelic is attached to the reg second stage at the mouthpiece with a small barb fitting. The operator then either inhales with his mouth or a vacuum generator (preferred) and you watch a pressure gauge that is attaced in some way to an intermediate pressure (IP) port or hose. The operator keeps his eye on the IP gauge and watches for it to drop a little bit. This drop shows when the regulator first and second stage seats have opened allowing air to move(inhalation). He then quickly looks at the value on the magnahelic to see if it is within desired inhalation specs .
In a reg manufacturers facility these of course are highly sophisticated often electronic instruments connected to pc's for recording and evaluation. Look up ANSTI breathing machine on google or something for details on that.
The value that you will see for inhalation effort is given in inches of water not psi as the psi value is so tiny they use water column instead. Just a set standard is all.
That value could be something like 1.2 inches water column (1.2"W.C. for short)
different manufactures wil specify different values but close to that. Often times exact same second stages , one as your primary and one as your secondary or octo will have different W.C. specs. This is because they intentionally detune the octo to minimize free flowing.
A simple way that many people use to check there regs is like what was mentioned above, the bucket of water.
With the bucket of water , and you can do this in the kitchen sink as well, you take your pressurized second stage regulator and hold it so that the diaphragm is as close to perfectly parallel to the water surface and slowly push it down into the water. Most regs will start to hiss (passing air) when the reg is approximately an inch to inch and a quarter deep. This typicalyy is before the lowest portion (the part that touches your teeth) of the reg is submerged. This is on typical regs. Having zero experience with Poseidon or Poseidon style regs I don't know how you would go about the bucket test with them.
If your reg doesn't flow around that point it may need to be checked. It would mean that it might breathe a little more effort than the human body likes if it didn't open up the seats.
Maybe a little long winded but it wasn't a quickie answer. There is alittle more involved but this was it in a nutshell.
Randy
