Vintage Double Hose

Needed something to do with this corona virus stay at home order so picked up a Calypso J regulator to rebuild. Read previous posts which were very helpful. WIth the regulator came this submersible pressure gauge. It still works showing correct tank pressure. It looks to have rotating bezel on the outside which does not seem to move? Some of the numbers relate to the S.Rate ? PSI/Min ? I can not read the brand name on the inside.
Any help in identifying it and info on how the bezel is suppose to work is appreciated.

It's a Farallon gauge.
With the outer rings you could figure how long your tank would last.

I don't have my device or the instructions handy, but i'm assuming it to be similar to the old NASDS "Scuba Time Calculator". Various alignments of the three indexes (pressure, SAC, Depth, time) will give you the other value (input one side of the equation).

Thanks for the info. I am soaking it in a salt away solution to see if I can get it to rotate.

The outer may never have rotated. In the NASDS STC, there is a fixed layer which is depth (ft) and consumption (psi/min). The rotating card was cylinder pressure (psi) , and dive time (min).

So with this one, the start point is pressure as indicated by the needle. From there, you would line up the depth you are at or planning to, and from there, if you know your consumption rate, it should indicate minutes of available gas...

so, something like 2600 psi at 40 ft, with a consumption of 20 psi/min is 60 minutes time...

can you align any of the info on the rotating card to look like that?

Try lining up tank pressure with your known consumption, then see what the psi/minute and time (outer ring?) show....

Got the ring removed from the gauge. It is just one fixed ring with outside numbers and inside ring numbers .I believe the outside numbers do relate to depth.. The inside numbers are divided between S.Rate PSI/Min and the other part reads PSI X 100. ( See picture) .

When I align up a depth to a particular pressure needle reading. it still does not make sense. ?

Thanks for any help.

I think the outside ring is time (min).

what is shown if you line up the needle reading of a tank with your rate, then look up a pressure on the opposite side where it then indexes minutes?

lets try something...

put 25 psi/min at the 3000 of the gauge needle. Where does the 3000 on the other side of the ring index to for minutes on the outside? 120?

does 2500 and 100 line up?