DIY dive computer pressure test chamber. Under $80

[KeithG]

BIG PS: My ancient vintage Oceanic DataMax Sport computer has a warning sticker to NOT test it in air. So I did not.

Does anyone know why?

I thought I had a good grasp of fundamental physics and have no idea why air pressure is different from water pressure....

 

[Couv]

My guess is that a fluid, for practical purposes, is not compressible. But a gas, being compressible, may make it's way past the seal and cause a bubble to form as the test pressure is reduced.

 

[rsingler]

Trying to find that online and not finding quite the same thing- If you get a chance please post the model number form the housing.

Thanks!

From General Electric, it's a GXWH40L, rated to 100psi (224 feet)!!
At Home Depot, the SKU is 859167; $62.98
Minimum internal dimensions of the clear cylindrical chamber are 4.5" x 9"
Diameter increases to 5.3" at the top, so you can get something a little bigger than 4.5" diam inside.
For camera housings, you're looking roughly at 3.5" x 4.5" x 9" max "box size" with maybe a little extra room for a protruding lens area on one side. Not much room for 150-foot-rated housings for most cameras, but exception posted above.

 

[beanojones]

BIG PS: My ancient vintage Oceanic DataMax Sport computer has a warning sticker to NOT test it in air. So I did not.
.

I think that that warning is on most dive computers. We always wanted to take computer into the chamber with us, but we had to do it in a pail of water, and that just made us want to pee.

 

[tc]

This is something I heard years ago, but never attempted to verify, so take it with a grain of salt.

The membrane ove the depth sensor is air permeable but not water permeable- I heard that on later model computers it was so that the computer could adjust for altitude before a dive.

 

[Murfi C]

great idea... but i think i'll start a lil higher than $150 lol... hardly worth the time/fuel etc... I may even start adding pressure guages to them for psi....

hi do you have it ready now?

 

[OTF]

I made the same thing out of a nearly identical water filter housing.

Introducing air to the system makes it dangerous. The "springiness" of compressed air stores a lot of energy and could violently rupture that housing. But water does not build up such explosive energy because it is effectively incomprehensible. Ideally you want to bleed out all the air from a high point, and pressurize the system using water. With no air in the system you can open a valve at full pressure and the water will just trickle out, no violence at all. Luckily this is very easy to achieve, you can use a cheap hand-powered grease gun to pump in water at extremely high pressures. Once all the air is bled out it only takes a couple squeezes to get into the hundreds of PSIs. Make sure you have a pressure relief valve and a good pressure gauge on it. Have fun bending the **** out of your dive computers.

Edit - just realized the original post is from 2013 and this was bumped. Lol.

 

[BlueTrin]

If you log 50 dives on your computer this way will PADI accept it as a proof of experience to apply for master scuba diver certification ?

He was congratulated on the steadiness of his ascent and descent rate.