In chemistry, pH is a measure of the activity of the (solvated) hydrogen ion. Pure water has a pH very close to 7 at 25°C. Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline.

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OP amp output cant go below below 1.8V

im kind a new in electronics so pardon me if i ask stupid question, im trying to follow this shcematic but im using op07 as buffer and LM336 as voltage reference, what happen is the op-amp (U1) ...
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46 views

interface two wire pH sensor with arduino

I have purchased this pH/EC sensor from https://www.cooking-hacks.com/ph-sensor however it does not have a BNC connector and just two wires, black and read. How could i interface this to an Arduino? ...
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pH sensor ground loop alike problem

I experienced the same as described in this question: A AD8603 is used as voltage follower to amplify the pH sensor signal to a microcontroller. As this opamp has a single supply and thus cannot ...
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0answers
127 views

Reduce power supply noise for pH measurement with Arduino module

I'm very new to the intergrated circuits and I'm trying to make a pH sensor with Arduino UNO and a cheap pH module. The pH module is connected to analog input pin of the Arduino. I have to use a DC/DC ...
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1answer
63 views

pH sensor, is the cebo-lc device suitable?

I would like to interface a pH probe. I know there are various threads on this topic. If found this two most interesting: Miceuz suggests two suitable instrumentation amplifiers (INA 116 and AD549). ...
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1answer
49 views

how to setup a ph sensor probe

I have a INA126 IN-Amp. I hope to use it with a ph probe. But I am not sure exactly how to do that. should I put the probe in series with a branch of a resistive wheat stone bridge, or just tie it to ...
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1answer
245 views

Tactics for stable unity-gain op-amp

The circuit given below is typical pH meter op-amp circuit. But here LMC6001 is not configured as unity gain. My question is this, I want to make this circuit with unity-gain buffer op-amp. What ...
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1answer
173 views

pH sensor project: trouble with RF interference

I built this pH sensor project on a breadboard and I'm having a big problem. The output on the voltmeter is completely erratic, and I'm pretty sure it's due to RF interference. When I connect the ...
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3answers
237 views

ESD protection for pH measurement electrode input

I want to puild a pH meter, which uses a normal glass electrode. Such an electrode behaves as a pH dependend voltage source (<+-500mV) with very high internal resistance (10MOhm - 1GOhm, depending ...
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3answers
631 views

Ground loop when measuring in process pH

I have been experiencing a very difficult to solve ground loop problem with my pH measuring system. My basic setup is a standard pH electrode running through an op-amp to an ADC which communicates ...
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1answer
249 views

Assistance with schematic notation “R@2V” for pH monitor

I've been building a circuit I found online for a pH monitor, while most of the circuit seems straight forward I get caught on the "R@2V" notation, a guess would be maybe resistance at 2 volts? I'm ...
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3answers
893 views

How do I hijack a reading from the circuit of my digital meter

I have a tri - meter (ph, ppm, temp) that reads and displays readings on three LCD screens. I'm trying to hijack the measurement at some point in the circuit and read it in through on of the inputs on ...
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1answer
946 views

pH sensor with DS18B20 temp compensation on PIC

I am trying to build a circuit that interfaces a standard pH electrode to a PIC (18F4550). I need the PIC to also use a DS18B20 for temp reading and use that data to correct the pH reading. I ...