Water level sensors

[John Charlesworth]

I believe you will find a suitable low-cost sensor for both water tanks
and seawater at:

http://www.electrosense.com.au

Regards

John

Derek Weston wrote:

Russ wrote:

I remember seeing a circuit for a water level sensor for tanks that
used a
pair of ultrasonic transducers atop a length of PVC pipe in SC or EA,

however for all my hunting I can't seem to find any reference to it.
Does
anyone know in which issue the article appeared, or of a similar
design that
I could use?

Russ.



http://www.robot-electronics.co.uk/shop/Ultrasonic_Ranger_SRF041999.htm

http://www.robot-electronics.co.uk/shop/Ultrasonic_Ranger_SRF082001.htm
http://hawthorn.csse.monash.edu.au/~njh/electronics/watersensor/
HTH

.... And on a similar topic, if anyone has devised a tide height and wave

height sensor which can be protected from spray without affecting
performance, and is not subject to marine fouling, I'd like to hear
about it.

 

[Russ]

"John Charlesworth" <wadsley@melbpc.org.au> wrote in message
news:3FF3F58C.1529FC1B@melbpc.org.au...

I believe you will find a suitable low-cost sensor for both water tanks
and seawater at:

http://www.electrosense.com.au

Regards

That's an impressive system - and a good range of interface options at good
prices. However, I need a level sensor for 2 different tanks, one is pure
rainwater, and it looks like their sensor relies on the dielectric
properties of impurities in the water, of which I imagine (and hope!) there
is very little in the rainwater tank. The other tank contains varying
proportions of reclaimed sewage water, overflow from the rainwater tank and
water pumped from a dam below, meaning that the dielectric properties would
change constantly.

Implementing a micro to time the pulses from an ultrasonic sensor in each
tank seems to be the best option that will cover both tanks.

Ultimately, I'd also like to run a simple HTTP server to display a status
page showing both tank levels along with historical information, however it
seems finding a cheap, single board solution to that problem is a little
more tricky.

Russ.

 

[John Crighton]

On Thu, 1 Jan 2004 23:36:19 +1100, "Russ"
<russell_UNSPAMME_@thehovel.net> wrote:

"John Charlesworth" <wadsley@melbpc.org.au> wrote in message
news:3FF3F58C.1529FC1B@melbpc.org.au...
I believe you will find a suitable low-cost sensor for both water tanks
and seawater at:

http://www.electrosense.com.au

Regards

That's an impressive system - and a good range of interface options at good
prices. However, I need a level sensor for 2 different tanks, one is pure
rainwater, and it looks like their sensor relies on the dielectric
properties of impurities in the water, of which I imagine (and hope!) there
is very little in the rainwater tank. The other tank contains varying
proportions of reclaimed sewage water, overflow from the rainwater tank and
water pumped from a dam below, meaning that the dielectric properties would
change constantly.

Implementing a micro to time the pulses from an ultrasonic sensor in each
tank seems to be the best option that will cover both tanks.

Ultimately, I'd also like to run a simple HTTP server to display a status
page showing both tank levels along with historical information, however it
seems finding a cheap, single board solution to that problem is a little
more tricky.

Russ.

Hello Russ,
sounds like you are into this water level monitoring in a big way.
You could ask your local shire council engineers what transducers
they use to measure water levels in their drinking water and
sewage holding tanks. You would probably get a few knock backs
when you rang up but if you e-mailed lots of council engineering
departments you would get some good answers.

http://www.radtel.com.au/index.htm
This company, Radtel in Thornleigh NSW is right into this
sort of thing. The boss, Mr Nisbet senior, makes up computer
programs to control his telemetry equipment with nice computer
graphic displays of water tanks, pumps, valves, sensors etc. All
controlled by mouse clicks, historical information also. Give Mr
Nisbet a call, but be warned he will probably give you a long
lecture on the subject. So if you are interstate be prepared to
spend a few dollars on the phone call. I am sure he will have
some answers for you also.

Over on science.electronics.design someone mentioned this
http://www.discovercircuits.com/PDF-FILES/capgage.pdf
on a discussion headed "osc.for capacitive proximity sensor"

Just for interest can you tell us a bit more about your water
controlling project?

Regards,
John Crighton
Hornsby

 

[Kevin Ettery]

Russ,

If you're willing to shell out a few bucks, a company called Milltronics (in
Sydney) sells an ultrasonic level sensor, called "The Probe"
(http://www.milltronics.com/product/product.asp?CFC=861), for about $900
(last time I knew that is). I have seen them used quite a bit in my line of
work (I am an Electrical Engineer working in the Water/Wastewater Treatment
industry for about 14 years - 12 in Canberra, 2 down here in Victoria's
Latrobe Valley).

Regards



Kevin


"Russ" <russell_UNSPAMME_@thehovel.net> wrote in message
news:bt1462$25ohl$1@ID-192123.news.uni-berlin.de...

"John Charlesworth" <wadsley@melbpc.org.au> wrote in message
news:3FF3F58C.1529FC1B@melbpc.org.au...
I believe you will find a suitable low-cost sensor for both water tanks
and seawater at:

http://www.electrosense.com.au

Regards

That's an impressive system - and a good range of interface options at
good
prices. However, I need a level sensor for 2 different tanks, one is pure
rainwater, and it looks like their sensor relies on the dielectric
properties of impurities in the water, of which I imagine (and hope!)
there
is very little in the rainwater tank. The other tank contains varying
proportions of reclaimed sewage water, overflow from the rainwater tank
and
water pumped from a dam below, meaning that the dielectric properties
would
change constantly.

Implementing a micro to time the pulses from an ultrasonic sensor in each
tank seems to be the best option that will cover both tanks.

Ultimately, I'd also like to run a simple HTTP server to display a status
page showing both tank levels along with historical information, however
it
seems finding a cheap, single board solution to that problem is a little
more tricky.

Russ.

 

[Russ]

"John Crighton" <john_c@tpg.com.au> wrote in message
news:3ff4a53b.8438121@News.CIS.DFN.DE...

Hello Russ,
sounds like you are into this water level monitoring in a big way.
You could ask your local shire council engineers what transducers
they use to measure water levels in their drinking water and
sewage holding tanks. You would probably get a few knock backs
when you rang up but if you e-mailed lots of council engineering
departments you would get some good answers.

http://www.radtel.com.au/index.htm
This company, Radtel in Thornleigh NSW is right into this
sort of thing. The boss, Mr Nisbet senior, makes up computer
programs to control his telemetry equipment with nice computer
graphic displays of water tanks, pumps, valves, sensors etc. All
controlled by mouse clicks, historical information also. Give Mr
Nisbet a call, but be warned he will probably give you a long
lecture on the subject. So if you are interstate be prepared to
spend a few dollars on the phone call. I am sure he will have
some answers for you also.

Over on science.electronics.design someone mentioned this
http://www.discovercircuits.com/PDF-FILES/capgage.pdf
on a discussion headed "osc.for capacitive proximity sensor"

Just for interest can you tell us a bit more about your water
controlling project?

Thanks for the contacts and other info - I must say, this particular
application is nothing particularly significant - it's just for a domestic
situation on a rural property. The house has a large concrete rainwater tank
which overflows into a smaller plastic tank, there is one of those aerated
bio-sewage units that periodically pumps out treated water into the same
plastic tank. In addition, after rain water is pumped up from a dam about
300m down the hill. In dire times, water is trucked in for the plastic tank.
This tank irrigates about 250 trees around the property.

As both tanks are about 40m and downhill from the house, it is difficult to
monitor both household consumption and irrigation usage, yet given the
recent drought, keeping an eye on this is becoming a very significant issue.

Thus, while running some new control cable down to one of the tanks, I threw
in some Cat5 into the conduit with plans to implement some kind of level
monitor, and remembered a circuit that had used a vertical length stormwater
pipe with a pair of ultrasonic transducers mounted through an end cap
pointing down. It seems the range sensor for robots that someone mentioned
here might do the same trick. Given there also seems to be some cheap micro
boards that have an Ethernet port and implement a simple web server, I was
thinking that the ideal way to view information would be via a PC in the
house, or by a wireless PDA/laptop browser elsewhere on the property. It
seems I will need to add in a micro to do the timing and store historical
readings in RAM that the web server can spit out.

The other alternative would be to have a server in the house that polled the
sensor and built its own log, which is probably simpler to implement, but
certainly more expensive and not as self-contained as a micro system.

Anyway, that's the theory - I'm hoping to implement without too much effort
or expense, although, that said I'd also like it to work

Russ.

 

[John Crighton]

On Fri, 2 Jan 2004 17:48:28 +1100, "Russ"
<russell_UnSpamMe_@thehovel.net> wrote:

Thanks for the contacts and other info - I must say, this particular
application is nothing particularly significant - it's just for a domestic
situation on a rural property. The house has a large concrete rainwater tank
which overflows into a smaller plastic tank, there is one of those aerated
bio-sewage units that periodically pumps out treated water into the same
plastic tank. In addition, after rain water is pumped up from a dam about
300m down the hill. In dire times, water is trucked in for the plastic tank.
This tank irrigates about 250 trees around the property.

As both tanks are about 40m and downhill from the house, it is difficult to
monitor both household consumption and irrigation usage, yet given the
recent drought, keeping an eye on this is becoming a very significant issue.

Thus, while running some new control cable down to one of the tanks, I threw
in some Cat5 into the conduit with plans to implement some kind of level
monitor, and remembered a circuit that had used a vertical length stormwater
pipe with a pair of ultrasonic transducers mounted through an end cap
pointing down. It seems the range sensor for robots that someone mentioned
here might do the same trick. Given there also seems to be some cheap micro
boards that have an Ethernet port and implement a simple web server, I was
thinking that the ideal way to view information would be via a PC in the
house, or by a wireless PDA/laptop browser elsewhere on the property. It
seems I will need to add in a micro to do the timing and store historical
readings in RAM that the web server can spit out.

The other alternative would be to have a server in the house that polled the
sensor and built its own log, which is probably simpler to implement, but
certainly more expensive and not as self-contained as a micro system.

Anyway, that's the theory - I'm hoping to implement without too much effort
or expense, although, that said I'd also like it to work

Russ.


Hello Russ,

thanks for telling me about your project.
I forgot to mention this mob
http://www.gme.net.au/commerc/telemetry_main.html
I know you are monitoring tanks that are not far away and
can use cables and do not need radios but GME might
still be worth talking to in regard to your sensors and for
general ideas. They sell a radio that looks like a UHF
CB radio but has a telemetry system built in. You might
as well get some prices and find out what they can do
telemetry wise.
That was the high tech suggestion.

Now, for some low tech suggestions.

Decades ago I visited the new Torrens Island power
station near Adelaide. I remember the guide explaining
how they monitored the water level in one of the boilers
from the control room which was quite some distance
away by using a series of mirrors. The guide explained
the water level was so important that a man had to
physically view the sighting tube which was a vertical
glass tube outside the boiler.
This had something to do with boilers and the law at
that time (mid 60's). They had other secondary electrical
ways to monitor the water level but the mirrors was the
primary way by law so I was told.
Maybe he was being over dramatic, I don't know.
They also had a TV camera permanently on the boiler's
glass water level tube and many monitors in different
places. The human eyeball on the tube was important.
Small TV cameras are so cheap these days, maybe
that would work for you Russ.

Another off the wall suggestion. Again, decades ago
I repaired a small cheap "Seafarer 3" echo sounder
that was working for years, monitoring the product
level of an oil tank at the Balls Head, Shell Oil terminal.
The transducer for this cheap little echo sounder was
mounted on a block of wood which floated on top
of the product. That's what they called the liquid in the
giant tanks when the operators were being vague.
You could call your sewage "product" also.
I like that name.
The echo sounder was in a little dog kennel type box
to protect it from the weather. The standard transducer
cable was extended to suit the height of the large
oil refinery type tank. These operators at the terminal
simply climbed on to the top of tank and took a reading
from the echo sounder's scale.

What I am leading up to is this.
I have seen cheap echo sounders having their transducer
cables extended so much that they become poor echo
sounders. But in your case, you are only measuring
the depth in a rainwater size tank. One fathom not
two hundred fathoms. Loss of range due an extremely
long transducer cable does not matter. You could have
the echo sounder head in your house and a long cable
to the tank. You can buy these old echo sounders for
around $20 at flea markets, garage sales and pawn shops.
For $50 to $100 you could buy a second hand digital readout
type. The old paper chart type could even be employed
if you made up a device to switch it on for several seconds
every hour. You would have a record of the water level
over a long time and use very little chart paper.

Regards,
John Crighton
Hornsby

 

[aussieblu]

Elektor Electronics had one (republished on page 362 of "308
Circuits" available from Jaycar) that uses a float and weight on
each end of a drive or band chain that turns a precision
potentiometer through a gear wheel.

--
Regards
Blue

Remove Z from email address to reply directly.

 

[Paul Bealing]

Russ wrote:

"John Crighton" <john_c@tpg.com.au> wrote in message
news:3ff4a53b.8438121@News.CIS.DFN.DE...


Hello Russ,
sounds like you are into this water level monitoring in a big way.
You could ask your local shire council engineers what transducers
they use to measure water levels in their drinking water and
sewage holding tanks. You would probably get a few knock backs
when you rang up but if you e-mailed lots of council engineering
departments you would get some good answers.

http://www.radtel.com.au/index.htm
This company, Radtel in Thornleigh NSW is right into this
sort of thing. The boss, Mr Nisbet senior, makes up computer
programs to control his telemetry equipment with nice computer
graphic displays of water tanks, pumps, valves, sensors etc. All
controlled by mouse clicks, historical information also. Give Mr
Nisbet a call, but be warned he will probably give you a long
lecture on the subject. So if you are interstate be prepared to
spend a few dollars on the phone call. I am sure he will have
some answers for you also.

Over on science.electronics.design someone mentioned this
http://www.discovercircuits.com/PDF-FILES/capgage.pdf
on a discussion headed "osc.for capacitive proximity sensor"

Just for interest can you tell us a bit more about your water
controlling project?


Thanks for the contacts and other info - I must say, this particular
application is nothing particularly significant - it's just for a domestic
situation on a rural property. The house has a large concrete rainwater tank
which overflows into a smaller plastic tank, there is one of those aerated
bio-sewage units that periodically pumps out treated water into the same
plastic tank. In addition, after rain water is pumped up from a dam about
300m down the hill. In dire times, water is trucked in for the plastic tank.
This tank irrigates about 250 trees around the property.

As both tanks are about 40m and downhill from the house, it is difficult to
monitor both household consumption and irrigation usage, yet given the
recent drought, keeping an eye on this is becoming a very significant issue.

Thus, while running some new control cable down to one of the tanks, I threw
in some Cat5 into the conduit with plans to implement some kind of level
monitor, and remembered a circuit that had used a vertical length stormwater
pipe with a pair of ultrasonic transducers mounted through an end cap
pointing down. It seems the range sensor for robots that someone mentioned
here might do the same trick. Given there also seems to be some cheap micro
boards that have an Ethernet port and implement a simple web server, I was
thinking that the ideal way to view information would be via a PC in the
house, or by a wireless PDA/laptop browser elsewhere on the property. It
seems I will need to add in a micro to do the timing and store historical
readings in RAM that the web server can spit out.

The other alternative would be to have a server in the house that polled the
sensor and built its own log, which is probably simpler to implement, but
certainly more expensive and not as self-contained as a micro system.

Anyway, that's the theory - I'm hoping to implement without too much effort
or expense, although, that said I'd also like it to work

Russ.


Hello

There was a digital water tank gauge project in Silicon Chip April 94 by
Jeff Monegal.
Ultrasonic, down a length of plastic pipe with a remote display option.

Regards
Paul Bealing
www.pmb.co.nz

 

[Russ]

"John Crighton" <john_c@tpg.com.au> wrote in message
news:3ff52154.40212557@News.CIS.DFN.DE...

Now, for some low tech suggestions.

Decades ago I visited the new Torrens Island power
station near Adelaide. I remember the guide explaining
how they monitored the water level in one of the boilers
from the control room which was quite some distance
away by using a series of mirrors. The guide explained
the water level was so important that a man had to
physically view the sighting tube which was a vertical
glass tube outside the boiler.
This had something to do with boilers and the law at
that time (mid 60's). They had other secondary electrical
ways to monitor the water level but the mirrors was the
primary way by law so I was told.
Maybe he was being over dramatic, I don't know.
They also had a TV camera permanently on the boiler's
glass water level tube and many monitors in different
places. The human eyeball on the tube was important.
Small TV cameras are so cheap these days, maybe
that would work for you Russ.

I was planning in the first instance to fit a length of clear tube up the
side. Maybe that and a telescope on the verandah of the house will do the
job!

Thanks for the suggestions - now I'll actually have to do something...

Russ.

 

[Russ]

"Kevin Ettery" <kpettery@dcsi.net.au> wrote in message
news:3ff4c27f@news.leadingedgeinternet.net.au...

Russ,

If you're willing to shell out a few bucks, a company called Milltronics
(in
Sydney) sells an ultrasonic level sensor, called "The Probe"
(http://www.milltronics.com/product/product.asp?CFC=861), for about $900
(last time I knew that is). I have seen them used quite a bit in my line
of
work (I am an Electrical Engineer working in the Water/Wastewater
Treatment
industry for about 14 years - 12 in Canberra, 2 down here in Victoria's
Latrobe Valley).

That reminds me - years ago between school and uni I worked for a pump sales
and repair shop in Fyshwick - from time to time ACTEW would dump a massive
rusty brown pump in the loading dock for servicing - from the look and smell
it had clearly been immersed in something unspeakable! At those moments I
was glad I didn't have ambitions to be a pump mechanic...

Our little wastewater recycling system probably doesn't really compare to
that scale of thing. I think I'm going to progressively try the simplest
and cheapest option an work up from there - which means in all likelihood
I'll end up getting that unit

Russ.