Bubbles in Depth Gauge

[Perryed]

I have a question that I think belongs here. I have an old Scubapro depth gauge that has a bubble in it. I don`t even know if it works or not. Would depths of ,say, 120 ft crush the air bubble and fracture the gauge? I`ve seen these bubbles in different equipment for sale over the years, especially compasses, and was curious. Thoughts?

 

[John C. Ratliff]

The bubble will probably simply decrease in size as you go deeper. But because it is compressible, your guage will probably read shallow. Take a look and see whether there is a small screw in the side or back which allows you to add more clear mineral oil to the gauge, and extract the bubble. If so, it can probably be put back into service. If not, then it can be safely taken to depth, but will most probably be inaccurate. I believe that the oil is inttroduced using a hypodermic needle, but since I have never done this, I'm not sure.

I have a similar Farallon with a similar bubble, but it is glued together and cannot be opened. It registers depth if I squeeze it, but I won't rely upon it for depth/decompression purposes.

SeaRat

 

[Perryed]

Thanks for the info. I thought there may be a way to get oil in there so I will look for a fill point. Although I think they were made like a cheap old snow globe and are probably not fillable.