Sensors for pH- (water, coffee, etc) DFRobot pH vs. EZO TM class embedded pH circuit

good day

hats off to you - i am overwhelmed by the awesome fritzing form here

at the moment i am in the early planning stages of a new projectr

I want to make a simple ph meter and display the ph value on an OLED/LCD display. I think I can learn a lot from this project; Something about the construction and functioning of the pH sensor.
Last but not least - if the system has to be calibrated (which I don’t necessarily “have to” have - then I would just “take it with me”. Then I learn the calibration method that determines the accuracy and accuracy of the sensor. But - as I said: actually I would like to get around the calibration. If that’s possible.

the options:

a. DFRobot Gravity Analog pH Sensor
b. EZO TM class embedded pH circuit: This is an … - TI E2 by : The Atlas Scientific EZO™

btw: I note that the Atlas Scientific EZO has a pH resolution of +/-0.002 - well i do not really need that high resolution!!! So i guess that i have to choose the DFRoboat Gravity
but here the comparison: which one is the best one!? to test water, Coffee, Tea, and so on (beverages)

see the both examples:
DFRobot Gravity Analog pH Sensor / Meter Kit For Arduino
30,26 € (Netto 25,43 €)
Artikelnummer: DF01035
GTIN: 4060137045332
Kategorie: Sonstige Sensoren
Hersteller: DFRobot

Modulpower : 5.00V
Modulsize : 43 x 32mm(1.69x1.26")
range :0 - 14PH
temperature: 0 - 60 °C
accurate ph-readings : ± 0.1pH
Reaction : < 1min
pH-Sensor with BNC-connector

EZO TM class embedded pH circuit This is an … - TI E2E

The Atlas Scientific EZO™ class pH circuit, has a flexible calibration protocol, allowing for single point, two point, or three point calibration. The other two …
• Full range pH reading from .001 to 14.000
• Accurate pH readings down to the
thousandths place (+/- 0.02)
• Temperature dependent or temperature
independent readings
• Flexible calibration protocol supports single point,
2 point, or 3 point calibration

DescriptionThe Atlas Scientific™ EZO™ class embedded pH circuit, is our 6th generation
embedded pH circuit. This EZO class pH circuit, offers the highest level of stability
and accuracy. With proper configuration the EZO class pH circuit, can meet, or
exceed the accuracy and precision found in most bench top laboratory grade
pH meters. The pH-EZO™ pH circuit, can work with any off-the-shelf pH probe/
sensor/electrode. This device reads pH from a pH probe/sensor/electrode. This
device does not include a pH probe/sensor/electrode.

btw: i think i will stick to the b.- the Atlas Scientific™ EZO™ class embedded pH circuit

i look forward to hear from you

So here’s a schematic drawing in advance - how I imagine it


    RG                             +-----------------+                       +--------------------+                                                   

          -------------------------|                 |                       |                    |                         +------------------------+

                                   |  mv-Amplifier   |                       |                    |                         |                        |

                                   |                 |                       | a/d-converter      |                         |  microprocessor        |

                             |---- |                 |-----------------------|                   ---------------------------|                        |

                             |     |                 |         |             |                    |                         |                        |

                             |     |                 |         |             |                    |                         |                        |

                             |     +-----------------+         |             +--------------------+                         |                        |

                             |                                 |                                                            +------------------------+

                             |                                 |                                                                        |             

                             |                                 |                                                                        |    -        

                             |                                +--+                                                                      |             

                             |                                |  |                                                                      |             

                             |                                |r1| r1                                                                   |             

                             |     -                          |  |                                                                      |             

                             |                                +--+                                                                      |             

                            --------------------------------- |                                                              +---------------------+  

                                                              |                                                              |                     |  

                                                             +--+                                                            |                     |  

                                                             |  | r2                                                         |  Display            |  

                                                             |  |                                                            |                     |  

  Referenc-electrode                                         |  |                                                            |                     |  

                   ---------------                           +--+                                                            +---------------------+  

                                  |                           |                                                                                       

                                  |                           |                                                                                       

                              --------                     ------

Further steps: i think about the interface:
a. Arduino
b. raspberryPi
c. ESP 32 /8266 …!?

i will create a Frizzing plan : where i take care for the periphery

. power supply
. Display
. resistors, capacities etc. etx
. OP-AMP etc. etx.

see more infos : Kalibrierung: vgl. Tutorial for analog pH sensor that's compatible with both Arduino and Raspberry Pi

in this video is an overview and tutorial for an analog pH sensor that’s >compatible with both Arduino and Raspberry Pi but I’ll also give a general >overview of linear functions and interpolation. Plus I’ll show you how to >write a custom code to use this sensor on an unsupported platform >(Espruino).
Measuring pH is pHun! (…I’m here all night folks.)

/* DF Robot Analog pH Sensor */

I look forward to hear from you

I think both sensors have Fritzing parts. A google search of the form “fritzing part ph sensor” should turn them up (as should a search in the forums as they are both posted here.) If they aren’t the model you need one of them can likely be adapted to fit.


1 Like

hello Peter,

many many thanks for the quick reply . I am very glad
i will do as adviced.

Greetings lisbon