[PSUBS-MAILIST] Depth Gage

[Jon Wallace via Personal_Submersibles]

Correct.


On 9/15/2015 9:14 AM, Alec Smyth via Personal_Submersibles wrote:
> Oh my, I have so thoroughly forgotten this stuff even though it was 
> used in every project back in college. The gauge comes in various 
> ranges, and I got the 500 psi model which has a minimum graduation of 
> 1 foot of water (no decimals). To summarize what you are saying, would 
> this correct? At any depth, I could tell if I were rising or sinking 
> with a 1 foot change in depth since that is the minimum graduation. At 
> full design depth of 1,000 feet, the accuracy of the depth reading 
> would be 2.5 feet. At shallower depths, the accuracy would be better 
> but we're not sure exactly by how much - I'd say its immaterial since 
> 2.5 feet is already more than accurate enough. There is also the issue 
> of fresh versus salt water having a 3% density differential, a way 
> larger "error" than the accuracy of the instrument. BTW the next model 
> up (DPG-200) has both fresh and salt water display units.
>