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Topic: Meassure PH of water (Read 4478 times) previous topic - next topic

sahanhasitha

I brought this ph module from ebay. But this gives me ghost outputs. They are not stable. I have no idea how to use this. Anyone have experience with this module? help me :)

jremington

You need to connect a pH probe to the module.

MaLi

looks like a classical two op. amps circuit. You will have to calibrate first. The two (blue) variable resistors are for calibration. The output is analog so you will have to calibrate that voltage on Arduino as well. If is 0 - 5 V the pH=7 would be 2.5V, etc.

hope it helps,
MaLi

sahanhasitha

looks like a classical two op. amps circuit. You will have to calibrate first. The two (blue) variable resistors are for calibration. The output is analog so you will have to calibrate that voltage on Arduino as well. If is 0 - 5 V the pH=7 would be 2.5V, etc.

hope it helps,
MaLi
Thank you buddy. Can you provide me a code for this? Do i need to connect Po pin to analog input of arduino?

sonnyyu

#4
Oct 01, 2015, 04:12 pm Last Edit: Oct 01, 2015, 04:25 pm by sonnyyu
You need to connect a pH probe to the module.
+1









sonnyyu

#5
Oct 01, 2015, 04:15 pm Last Edit: Oct 03, 2015, 05:32 pm by sonnyyu
I brought this ph module from ebay. But this gives me ghost outputs. They are not stable. I have no idea how to use this. Anyone have experience with this module? help me :)


Vph-=Vzener/2

p_AOUT is output of PH. connect digital multimeter to confirm.



sonnyyu

#6
Oct 01, 2015, 04:18 pm Last Edit: Oct 01, 2015, 04:19 pm by sonnyyu


Calibrite meter.




ODwyerPW



This is you first post.  I would suggest searching these forums for pH.  There is a wealth of information available.

Look at Atlas-Scientific.com for help as well. They sell interface modules and give Arduino code for their use.




sonnyyu

#8
Oct 03, 2015, 05:20 pm Last Edit: Oct 03, 2015, 05:28 pm by sonnyyu


  • E0:Base line voltage
  • R:Ideal gas constant.
  • T:Temperature in Kelvin.
  • F:Faraday constant.




https://en.wikipedia.org/wiki/Glass_electrode

Temperature in Kelvin here is temperature of water, not temperature of environment (air) .

Atlas-Scientific.com's product & above product are failed here.



sahanhasitha


dwightthinker

Make sure you store the probe in the correct fluid. It has been
a long time since I used one of these so I don't recall if it was some
buffer solution or just DI water??
If you are using the Rt in the schematic to measure temperature,
make sure it tracks the temperature of what you're measuring.
Dwight

jack wp

#11
Oct 04, 2015, 11:57 pm Last Edit: Oct 04, 2015, 11:57 pm by jack wp
I brought this ph module from ebay. But this gives me ghost outputs. They are not stable. I have no idea how to use this. Anyone have experience with this module? help me :)
That means that your reading is jumping  around.
How much are they jumping around? Show us about 20 readings so we can see.

You may want to add more capacitors to the power busses, and maybe try one on the analog pin.
What analog pin are you using?
can you show us the script (in code tags </>) ?

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