On Sat, 20 Aug 2011 19:11:12 -0500, G. Morgan wrote:

Why 6 sensors? You would just need two on each tank, like how limit
switches work in garage door openers. Or are you going for greater
resolution?

Seems to me, if the work is going to be done to fit sensors, one may as
well measure with greater granularity, than less.

On Sat, 20 Aug 2011 18:13:39 -0700 (PDT), wrote:

they will just sound an alarm when it reaches any one of them.

The thought was that the sensors are 'shorted' with water such that they
remain shorted and continually show a short ... thereby triggering
something (e.g., a light) which stays on as long as the sensor wires are
shorted (by the water).

At least that's how it looked to me.

they would probably all be wet enough to
trigger the alarm.

I thought about that too. The inside of a holding tank is very humid.
Soaking wet humid, in fact. So, it really depends on how well the sensors
reject super saturated air.

All that tells you is that at least one sensor
is wet, not which one.

Hmmmm... that would be bad news. I 'thought' each sensor would be a
different 'zone' so that the warning light would be a ladder of sorts.

For example, zone 1 triggers at, say, 1/6th the tank, zone 2 triggers at
2/6th, zone 3 at 3/6ths, etc., until zone 6 triggers at full.

On Sat, 20 Aug 2011 18:16:01 -0700 (PDT), wrote:

The weight of the water in the tank creates pressure and
that is what you measure with one transducer. That
pressure tells you the exact level of water in the tank.

I like that idea.

It's simple, and linear.

Now to find the sensor ... I'll google.

wrote:

Since a well holding tank has got to be wet inside, key to operation is the
sentence "Will not alarm due to condensation or humidity".

I wouldn;t count on taking it to the extreme of the inside of
the tank. I would take it to mean the condensation or humidity
you would find on a basement floor or a laundry room.

That' not how they work, there are 4 pick-up's on each sensor on each
corner. If he mounts them right there is no problems of humidity to
worry about. They are fully submersible (of course).

SF Man wrote:


Hmmmm... that would be bad news. I 'thought' each sensor would be a
different 'zone' so that the warning light would be a ladder of sorts.

For example, zone 1 triggers at, say, 1/6th the tank, zone 2 triggers at
2/6th, zone 3 at 3/6ths, etc., until zone 6 triggers at full.

Yes, you can do it like that. Waterbugs are submersible, that's why
they say can "detect ABSENCE of water". I've been in the business a
while, and they are reliable (first hand experience). The other
Winland environmental sensors are great too.

On Aug 21, 5:25*am, G. Morgan wrote:
SF Man wrote:

Hmmmm... that would be bad news. I 'thought' each sensor would be a
different 'zone' so that the warning light would be a ladder of sorts.

For example, zone 1 triggers at, say, 1/6th the tank, zone 2 triggers at
2/6th, zone 3 at 3/6ths, etc., until zone 6 triggers at full.

Yes, you can do it like that. *Waterbugs are submersible, that's why
they say can "detect ABSENCE of water". *I've been in the business a
while, and they are reliable (first hand experience). * The other
Winland environmental sensors are great too.

Yes, he can do it like that. But as I recall, there are two tanks
in question and they are 100 to 200 ft from the house. He wants
to know the level of water in each of the tanks. Let's assume
they are just connected directlyh together, in which case the
water levels are the same. To get that level with
a reasonable degree of accuracy he's need about 6 of these
sensors. Then, he'd still need to somehow get the results
back to the house. Which means either running these
waterbugs individually back to the house, or else using
wireless networking with an I/O device to read the status
of the waterbugs and then send it to the home network.
Even if he does individual runs, then what? He still
needs something to display the status because
from the spec sheets neither the WB200, nor the
WB350 has a display. If he wants to go that route,
he could use 8 sensors and the WB800, which
appears to have a suitable display. But doing 6 or 8
runs of wire 100 - 200 ft outside sounds like a PIA.
Plus, don't know how he feels about the price, but
online a WB800 plus another 4 sensors is ~ $260


And if he goes the wireless route, instead of a bunch
of sensors he could use one transducer that measures
water pressure in the bottom of the tank and
know exactly how much
water he has. He just has to interface that to an
ethernet I/O device that is compatible.

On 8/21/2011 8:12 AM, wrote:
On Aug 21, 5:25 am, G. wrote:
SF Man wrote:

Hmmmm... that would be bad news. I 'thought' each sensor would be a
different 'zone' so that the warning light would be a ladder of sorts.

For example, zone 1 triggers at, say, 1/6th the tank, zone 2 triggers at
2/6th, zone 3 at 3/6ths, etc., until zone 6 triggers at full.

Yes, you can do it like that. Waterbugs are submersible, that's why
they say can "detect ABSENCE of water". I've been in the business a
while, and they are reliable (first hand experience). The other
Winland environmental sensors are great too.

Yes, he can do it like that. ...

....[discussion on connections/display/etc elided for brevity]...

And if he goes the wireless route, instead of a bunch
of sensors he could use one transducer that measures
water pressure in the bottom of the tank and
know exactly how much
water he has. He just has to interface that to an
ethernet I/O device that is compatible.

As well, I'd question how well the waterbug will work as a level sensor
rather than a dampness detector as it is intended. In a tank the wall
will still be wet after the level has dropped past it for a (probably
considerable) length of time and I'd wonder what the sensitivity will be
to detect that film surface...it might work satisfactorily but reading
the doc's online doesn't give me a warm fuzzy that they're at all
designed for the purpose. Perhaps the sensitivity is adjustable or they
require more water than the damp surface but I'd surely go w/ a trial
run or talk w/ manufacturer on the proposed application before I'd spend
much money on the idea.

--

SF Man wrote:
On Fri, 19 Aug 2011 05:00:57 +0200, Sjouke Burry wrote:

put reed relays along the pipe, which switch a row of say 10-20 leds.
That should give you a nice display

I'm amazed at the ingenuity of the suggestions!

This idea seems elegant.

A pipe with a floating magnet (either inside the pipe or a ring outside the
pipe).

As the magnet moves up and down, differnet switches are turned on or off.

Are you suggesting that the one switch which is 'active' would be the water
level?

I guess that would take a lot of reed switches ... to cover about 5 feet of
water level travel ... but the result 'would' be an interesting display in
the kitchen!

I was thinking immersed thermisters. Self heat generators just like a gas
tank. You might be able to use a small bank, how many do you need, there
are temperature sensors that have an adjustable range, with on on off
output. Same as magnetics without need for magnet.

Greg

a different approach add a tank for non essential uses like watering
lawn etc.

when its dry you dont irrigate.

this would add capacity and be realtively simple to implement.

no sensors needed other than protection for the pump irrigation.....

i did something similiar when just out of high school my mom depended
on a cistern which would spill water when full.

i added a tank to the spillage line, and mom used the waste water to
irrigate her garden. the cistern was on top of the hill so no pump
was needed

of course drip type irrigation would cut water use dramatically

On Aug 21, 1:49*am, SF Man wrote:
On Sat, 20 Aug 2011 18:16:01 -0700 (PDT), wrote:
The weight of the water in the tank creates pressure and
that is what you measure with one transducer. *That
pressure tells you the exact level of water in the tank.

I like that idea.

It's simple, and linear.

Now to find the sensor ... I'll google.

Another simple possibility. If you don't mind running a wire
from the tank to the house, you could probably use an
off-the-shelf water pressure gauge for auto or marine.
You get a transducer and a gauge that work off 12V.
You'd need one that reads from 0 to about 25 psi and
I think you could find one close to that. Then you'd
have a gauge that shows the water level.