well depth sensor

[philba]

given that it could be as far as 620 ft, I kind of doubt that would work. Also, there will be a lot other stuff in the well casing, I'm not even sure there is clear sight of the bottom.

 

[grim]

submarines manage it over greater distances

a machine that drops stones, and times the splash. that's a friday afternoon suggestion

woow hang on, a bright idea (well a brighter one)

two uninsulated conductors running down the side of the well, and measure the resistance between them? the lower the water the higher the resistance

 

[philba]

yes but
a) submarine sonar is very powerful - it can kill marine life. Pricey even if not restricted.
b) submarines don't try to shoot the beam down a 1.5" pipe.

the resistance idea is on a sound theoretical basis but has lots of practical complications: corrosion, differing conductivity of the water over time and mechanically maintaining the distance between the wires in a 1.5" pipe while avoiding contact with the metal shaft. If one was willing to attempt that, a better solution would be measuring capacitance between two sealed wires. However keeping the wires at a uniform distance over a 600' height is just not practical.

Personally, I think measuring the head pressure while pumping is the best solution. it does mean that you can't monitor on a minute by minute basis but don't think it's all that valuable. I think you can derive all the info you want from that data. To get minute-by-minute data with the pump off, the bubbler is the best solution.

 

[grim]

final Friday night idea

blow air accross the top of the well, and record the frequency of the whistle.

lots of research can be performed blowing accross beer bottles with various amounts of beer in them..........

I am conducting this research as I type.

 

[alternety]

I have also considered trying to capture neutrino flux markers and calculate the volume of the water. With a known diameter of 6" - the volume of equipment/pipes/wires embedded a fairly accurate number can be derrived.

 

[philba]

Hmm, what kind of sensor would you be using?

By the way, is your retirement home in the San Juans? I know that's a very challenging environment regarding water.

It's Friday afternoon so I think I'll do some research on the whistle idea. I kind of think it definitely needs some study.

 

[alternety]

Philba,

I actually put my location in the post just before yours. I am in Anacortes. I am on a part with no aquifers per se. It is a fairly large area on the South end.

I will probably use a simple pressure sensor IC.

 

[alternety]

Now I need tubing. So far all I have found with sufficient pressure rating is reinforced poly at almost a buck a foot.

Suggestions?

 

[jpanhalt]

Since the airflow in the tube will be low, I would consider decreasing the diameter to attain the pressure rating you need. McMaster-Carr has a nice variety of nylon tubing available at less the $0.25 per foot. See: mcmaster.com
John

 

[john1]

Yes, just what i was about to suggest.
Thinner tubing can handle much higher pressures,
but if you go very thin the response time will be increased.
Less than a quarter of an inch will take quite a while to squeeze
out the water to get an indication.

Unless you leave it bubbling all the time i suppose.

John