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Unread 05/24/2010, 05:43 AM   #26
cyrusthevirus
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I have not even had a chance to work on it. I am still working to complete the lighting system. I currently only have a sump running which is filled with live rock. So my priority is the lighting system so I can setup the main tank. We do however have another person who will begin testing with us soon. I should be sending out a board and probe to him this week.


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Unread 05/24/2010, 06:43 AM   #27
BeanAnimal
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Great!

Don't get me wrong... I have a feeling the circuit will work, I just think it will be tempermental and can be improved upon I did not intend on designing my own and had hoped that somebody else already did the work. We all know how that goes though.


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Unread 07/09/2010, 08:10 PM   #28
cyrusthevirus
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BeanAnimal and anyone else doing testing on this how are you making out?


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Unread 07/10/2010, 08:24 PM   #29
BeanAnimal
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I did not build that circuit (for the reasons I mentioned). I have designed my own and have all of the parts on the bench, but have not had a chance to toss them on the breadboard yet. I have my hands full with a new custom shed (workshop for wood and electronics) and our clubs summer picnic (I am hosting) along with work.


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Unread 07/19/2010, 06:22 AM   #30
cyrusthevirus
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No problem just wanted to see if there was any progress on a DIY conductivity meter.


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Unread 09/12/2010, 05:07 PM   #31
sheac12
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BeanAnimal,

Can you post your updated conductivity opamp design?


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Unread 12/03/2010, 09:42 AM   #32
simon owl
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DIY Conductivity Probe/Meter Reply to Thread

Hi

Just wondering if anyone is pursuing this project.

I am really keen to build a diy salinity sensor,

I too tried this one http://www.octiva.net/projects/ppm/ but then found it only goes up to something like 2500PPM salinity. So when I tried it out on salty water the circuit was way off the scale.

Obviously for testing fresh water.

drinking water - 100 ppm
restriction on drinking water - 500 ppm
limit drinking water - 1000 ppm
limit agriculture irrigation - 2000 ppm
brackish water - 500 - 30,000 ppm
sea water - 30,000 - 50,000 ppm
brine > 50.000 ppm

I would love to hear if anyone is still working on this, and have any more nuggets of information.

Does it get harder to get a conductivity measurement when salt levels get above 2500ppm ?

Cheers

Simon


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Unread 12/06/2010, 08:42 PM   #33
cyrusthevirus
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Not sure, but I thought it was the probe that set the level, not the circuit.

BTW I sent you an email about the cost for a test board.


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Unread 12/06/2010, 09:30 PM   #34
BeanAnimal
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I have not had any time to work on my design. I will pick the project up after Christmas.


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Unread 03/29/2011, 05:08 PM   #35
MaLi
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Hey gents ... any news on this approach ?

cheers,
Marian


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Unread 03/30/2011, 02:04 PM   #36
cyrusthevirus
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Not yet. I ran into a problem with my program so I have not had a chance to get back to this circuit.


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Unread 06/19/2011, 05:07 PM   #37
BeanAnimal
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You said in your other post that you were not trying to sell anything, yet your site does not have schematics or firmware and appears to be a sales pitch with "hobbyists and developers" as your target.

Your name "OEMTDS" appears to directly indicate that you are a product manufacturer.

You appear to be asking questions in order to understand what our hobby needs in the way of sensors. Will you be providing schmatics, circuit operation explanation and open source firmware? Your other post does indicate "open source" so where is the source?


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Unread 06/19/2011, 05:08 PM   #38
BeanAnimal
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Quote:
Originally Posted by MaLi View Post
Hey gents ... any news on this approach ?

cheers,
Marian

My project is also on hold.


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Unread 06/19/2011, 10:36 PM   #39
oemtds
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It is an open source when someone emails me or shows interest SIR...so far i got nothing but bunch of bickering from you . Yes i kept my nickname oemtds which means nothing but a tds.Besides does that web link look like a business page to you? I see lots of ppl promoting their tanks and set ups as being one of a kind ,why cant I ?


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Unread 06/19/2011, 10:41 PM   #40
oemtds
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Quote:
Originally Posted by simon owl View Post
Hi

Just wondering if anyone is pursuing this project.

I am really keen to build a diy salinity sensor,

I too tried this one http://www.octiva.net/projects/ppm/ but then found it only goes up to something like 2500PPM salinity. So when I tried it out on salty water the circuit was way off the scale.

Obviously for testing fresh water.

drinking water - 100 ppm
restriction on drinking water - 500 ppm
limit drinking water - 1000 ppm
limit agriculture irrigation - 2000 ppm
brackish water - 500 - 30,000 ppm
sea water - 30,000 - 50,000 ppm
brine > 50.000 ppm

I would love to hear if anyone is still working on this, and have any more nuggets of information.

Does it get harder to get a conductivity measurement when salt levels get above 2500ppm ?

Cheers

Simon

That design is not an ideal salinity tester . I do have much better schematics but what do i know im just promoting a product here huh.


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Unread 06/20/2011, 05:48 AM   #41
cyrusthevirus
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Quote:
Originally Posted by oemtds View Post
I see lots of ppl promoting their tanks and set ups as being one of a kind ,why cant I ?
I do not hink he is complaining about the promotion, but we are all here to learn from each other to improve this hobby. Can you post your schematics for us to learn from? I would love to see them.


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Unread 06/20/2011, 07:07 AM   #42
BeanAnimal
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Quote:
Originally Posted by oemtds View Post
It is an open source when someone emails me or shows interest SIR...so far i got nothing but bunch of bickering from you . Yes i kept my nickname oemtds which means nothing but a tds.Besides does that web link look like a business page to you? I see lots of ppl promoting their tanks and set ups as being one of a kind ,why cant I ?
I am not bickering, I am telling you that your posts appear to be in the spirit of promoting a product not sharing your work. Furthermore, a simple search of your name "OEMTDS" shows similar posts and numerous reef, hydroponics and similar forums where you offer kits and customization of conductivity products. In most cases you have been banned for solicitation.

OEM (as you know) stands for Original Equipment Manufacturer. So your name appears to indicate a commercial interest in design and sale of TDS measuring equipment.

You have come here asking questions regarding the needs of our hobby, yet your porfile indicates 10 years of experience in our hobby. I would think that If you had 10 years experience in the hobby you would know the needs of the hobby.

You have indicated that you are not trying to sell anything, but the wording of your posts and website (along with your name) appear to indicate that you wish people with interest to contact you so that you can arrange a transaction to customize a product to their needs. Furthermore, some of your pages (not linked here) do list product pricing and a shopping cart for the exact same model you have posted at your "hobby" page. In all of those forums that you have posted to, not once have you posted your "open source" design. Instead you simply posts links back to your site, in some cases even acting like it is not YOUR site, but one you hav stumbled upon that can help others.

I am calling your bluff OEMTDS. You say your project is open source, then post it here so that we can comment and/or benefit from the work as a community. Many of us are electronics hobbyists and/or designers and would welcome the dialog. If on the other hand you are looking to generate private transactions via email (or other means), this is the wrong place.



Last edited by BeanAnimal; 06/20/2011 at 07:39 AM.
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Unread 06/20/2011, 11:04 AM   #43
Randy Holmes-Farley
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OEM, how many electrodes does your unit use?

What about temperature?

I wouldn't want a sensor that did not innclude temperature, and I'd strongly prefer 4 electrodes.


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Unread 06/20/2011, 12:13 PM   #44
liquidcowboy
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Cyrus,

I tried to reply to your pm but it said that pms are not being accepted.

But to answer your question, from what I have researched so far I was thinking of going with the arduino and ATMega324. Is that a good choice or would you recommend something better? I was also looking on sparkfun and like the idea of using the touch screen shields for the display.


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Unread 06/20/2011, 08:07 PM   #45
oemtds
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Here is what i have . It is a single chip op amp based circuitry with stable ac drive source . Range is configured with a gain resistor .Output even though says 3vdc(for 3000micro/S) can be 0-5vdc (0-5000 micro/S) suitable for arduino or any other microprocessor analog input. My complete sensor has this circuit board and 2 graphite electrodes already connected to 1/2" pvc. Now if you choose to have your own sensor connected to it, you can do so.Termp compansation resistance has to be some where arround 2.5k PTC. Default value is 2.5k resistor soldered on the board.My question was ,as i read your comments ,you want to control some where from 0 to 50000micro/S ?
Thats impossible. Here is why
1. if youre using graphite electrodes...you may get good readings at high tds but it wont be accurate 0-200micro/S .You have to use stainless steel.
2. Unless you have a trimpot which will change the gain of the op amp between high and low to manupulate range ,but thats not gooing to be accurate. Not practical.

In this circuitry you have to choose appropriate gain resistor for ranges 10s .100s or 1000s.


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Unread 06/20/2011, 08:38 PM   #46
oemtds
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Quote:
Originally Posted by Randy Holmes-Farley View Post
OEM, how many electrodes does your unit use?

What about temperature?

I wouldn't want a sensor that did not innclude temperature, and I'd strongly prefer 4 electrodes.
its a 2 electrode not 4. I know 4 is more favorable.
Has temp comp and based on my tests it produces 2% change from full scale from room temp to lets say 100F.Accuracy is about 4% from full scale . Overall its a good device for $40 which measures and provides dc output for arduino.What more can you ask. I know there are commercial high end $2000 instruments. This is not one of them .


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Unread 06/21/2011, 04:36 AM   #47
Randy Holmes-Farley
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Thats impossible. Here is why
1. if youre using graphite electrodes...you may get good readings at high tds but it wont be accurate 0-200micro/S .You have to use stainless steel.
2. Unless you have a trimpot which will change the gain of the op amp between high and low to manupulate range ,but thats not gooing to be accurate. Not practical.


My commercial conductivity meter (Orion 128) has several selectable ranges, spanning well beyond what you are quoting, with a single set of electrodes. So it is not impossible, but perhaps not a simple DIY. Not $200 either, but perhaps not a DIY.


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Unread 06/21/2011, 09:15 AM   #48
BeanAnimal
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Forgive me for being blunt, but I still don't see a schematic, bill of materials or construction instructions. I just see a person attempting to generate business interest without providing DIY information.

I too can label an image and provide information about it without providing construction details, schematics or a bill of materials. Below is SBC type PC used in a car MP3 Player.




Are you going to share the full plans for the project or not?



Last edited by BeanAnimal; 06/21/2011 at 09:29 AM.
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Unread 06/21/2011, 07:31 PM   #49
oemtds
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Yes Randy your "commercial" meter has selectable ranges(aka changes resistor values) but have you tested see if it will read DI water and then 50000Micro/s dead on? If it does great. Mine is not a commercial product nor it costs $200.
Anyways i showed what i have made . So far i see sheac12, cyrusthevirus constantly asking BeanAnimal to show his project but for obvious reasons its on hold.
Instead he 's showing whats inside his mp3 player hahaha.
Anyways you guys are too much fun.


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Unread 06/21/2011, 07:36 PM   #50
oemtds
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Randy ... you are correct ...Perhaps i can add a selectable switch to change the range on mine but i always thought for low conductivity stainless electrodes work best. What kind of tips does your electrode have.?
I hope we are talking about inline continuous monitor verses lab model.
Mine is inline type that provides 0-5vdc to arduino and from there you can customize from touch screen control panel with tons of parameters to mobile ,txt and so on. And all that cost me $40.



Last edited by oemtds; 06/21/2011 at 08:00 PM.
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