Digital depth gauge

[Atle.norway]

Looking for a digital depth gauge .so i can sit and control the rov and seeing actual depth.
I can use a analog one in front of the camera,but was hoping to avoid that.
Any ideas?

[Joe]

The "old fashioned" way of finding depth is to have a little air line running down to the ROV with the end open so the air just bubbles out. Then the air pressure in the hose can be measured at the control station and that pressure will tell you the depth of the ROV. (Depth in feet = PSI * 0.45, Depth in Meters = Pressure (Bar) / 10)

[njs552]

How about something like this?

http://www.ebay.com/itm/250799543734

It outputs a analog voltage from 0-5v based on hydrostatic pressure. It is made to be mounted to a pressurized pipe, but I figure it would work just as well inside a pressure vessel on an ROV. I just recently came across these, and they seem like a very good option because the data could be read very easily with an Arduino. Since an analog pin on an Arduino measures a value 0-1023, I think it would be very simple to set up and pretty accurate.

This particular sensor is 0-100psi, but there are other models in 15,30,80,100,300,etc.

I do not see anything about whether this gauge measures gauge or absolute pressure, so there are two different maximum depths of this sensor:

14.7psi = 1bar = 101.3kpa = 1atm = 33ft(10m)
Using the known values above here are the max depths:

Absolute: (sensor measures against a perfect vacuum, so ambient atmospheric pressure has to be included, ~15psi.)
100psi -15psi(ambient) / 14.7psi = 5.78 * 33ft = 190ft(58m) <-- Max depth w/ absolute reading
Gauge: (sensor measures against ambient atmospheric sensor)
100psi / 14.7psi = 6.8 * 33ft = 224ft(~70m) <-- Max depth w/ gauge reading

Hope this helps!
njs

[Atle.norway]

Thank you will try it.i recently made my own light panel.the lumen ( lightstrenght) is 480 and thats only four lights.i calculated if i added 16 in all ,i can boost thelumen up to 1920 and i will only draw 4 amps
Very cheap.let me know if your intrested i wil give you all info.

[Toffe]

Thanks for asking just this. I'm also a ROV builder from norway. Wondering about the light you told about? Could you post some images of that?

[Atle.norway]

Can send you pics from it.but i cant seem to post pictures on this forum.tried everything.downzising quality down to 70% nothing seem to work.
Anyway its a cheap and reliable way of making lights
I used 4 2watt 12v led socket bulbs and just glued all joints .conetcted to a test battery and dropped it in a bucket with water for 5 mins.
Used a pieac of plexi and drilled out holes for the bulbs
Send your email and i will send pics of it.mine is atle.gronsund1985@ gmail.com