Project for ph-measurement: which sensor-type should i use?

hello dear friends,

i am willing to start a project for ph-measurement:

pH measurement has many uses - for example for all sorts of laboratory and industrial uses.

i want to run a Arduino to read pH, log it, and integrate it into a concept that runs more sensors.
pH (power of hydrogen) shows us how how acidic or basic a water-based solution is. This is a equivalent of electrical power...
to be more precice - the ph shows us a value of the concentration of hydrogen ions (H+) present in a probe.
i have tried to make up my mind and have read some forum threads here - and more stuff to dive into the technique: - as of the learing curve i have went through - i have to recap.

As of being in the early planning stages i have heard of different types of sensors.

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

Question: which one is the best one!?

see the both examples:

a. 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
pH2.0-interface ( 3-Fuß-Patch )

pH-Messtaster (BNC-Stecker) x1
pH-Sensor-Leiterplatte x1
Analoges Kabel x1
Link; DFRobot Gravity Analog pH Sensor / Meter Kit For Arduino - Epaper EIn

b. 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
• Calibration required only once per year with
Atlas Scientific pH probe
• Single reading or continuous reading modes
• Data format is ASCII
Two data protocols
• UART asynchronous serial connectivity
• (RX/TX voltage swing 0-VCC)
• I
C (default I2
C address 0x63)
• Compatible with any microprocessor that supports
UART, or I2
C protocol
• Operating voltage: 3.3V to 5V
• Works with any off-the-shelf pH probe
Sleep mode power consumption
• 0.995mA at 3.3V

The 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.


So the question is: which one is the appropiate one - which one would you use in the project!?

love to hear from you


It appears you want to build a solution without a problem. Tell us what you are measuring, what temperature range, accuracy, deavation, etc. What is your budget, these sensors can get very expensive.

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"build a solution"



I have been working with my brother on a river water quality monitoring system for the last several years. We use the Atlas Scientific probes and interface boards. Their latest offerings appear to be even better than what we got three years ago. I would recommend the kit that includes the isolated carrier board. A pH probe is a very high impedance device and very noise sensitive.

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hello dear oldcurmudgeon

many many thanks for the quick reply - and for all your ideas, suggestions and for sharing your experience.

Glad to hear from you. I will go with the Atlas-kit.

PS - this is a awesome forum - a great place for all the Arduino questions.

Have a great day