GFET pH sensing


The purpose of this document is to provide users the instruction to get started with GFET pH measurement. The step by step procedure for the measurement is provided in the section below.



The scope of this document is limited to the GFET pH measurement using open circuit potential method (OCP) on the potentiostat channel zero (POT0) on the GFET PCB. 




OCP is open circuit potential

SPE is screen printed electrode









1. Connect the SPE ZP pH sensor to the connector on GFET 

2. Connect the GFET using a micro USB cable to the PC


3. To verify if the device is connected properly and enumerated as a COM port, open Control Panel->Device Manager->Port and find COM number (COM5 in this case).

4. Open any terminal application such as TeraTerm ( to view the data from the GFET. The baud rate must be set 57600 bps.

5. Once the device is connected the user can see the pH measurement values in volts displayed in the user interface (see image). The data can be later used in Microsoft Excel or python script for further processing and visualization.    2021