pH Meter for Wine & Environmental Testing

🔘This pH meter, ( abbreviated PHM ), measures the pH# of liquids🫗 to determine the degree of acidity or alkalinity. The pH measurement range is from 0 to 14; pH<7 is acidic, pH=7 is neutral and pH>7 is alkaline. In addition to having uses in the environment🏞 for assessing water quality, the PHM was designed particularly for applications in winemaking🍷 to check if the pH of the 🍷wine lies within the optimum range of 3.0 to 3.4.

The complete PHM with probe connected - note the micro usb connector

The constituent parts of the PHM are the pH probe ( connected by cable terminated in a BNC connector ) plugged into the case which contains the probe control module, ų-controller and rechargeable 🔋battery. The probe, its control module and a ESP32 based ų-controller board are commercial items which are available for purchase from numerous vendors. The case is a custom SpacerLabs design and was 3-D printed. The ų-controller is programmed with custom SpacerLabs in-house software. The PHM is powered by an internal rechargeable 🔋battery, or externally via usb ( pc, power bank, usb charger etc ).

Internal view showing battery & (L) control module (R) ų-controller

Three versions of the PHM have been developed; 2 WiFi versions ( station or soft access point ) and a BluetoothⓇ ( BLE** ) version.

There is no integral display to display the pH measurements*. So instead the measurements are read from a user interface ( UI ) typically on a smart phone having wireless connectivity with the PHM, and either a 🕸web-browser or the custom SpacerLabs App "pH_Meter_vn.m" installed.

Before first use the PHM was calibrated using standard buffer solutions of pH4, 7 & 10. 

Though not necessary when the PHM is in normal use, serial data at 115200Bd can be displayed for diagnostic & development purposes by using a terminal emulation program e.g. SpecTecsTerm, on a pc💻 connected to the micro-usb connector, which is also used to charge the battery🔋. The PHM is declared as a virtual COM port.

The 📖User Manual can be downloaded 🔗here.🔲

 

# pH - hydrogen ion concentration, potential of hydrogen.

* A version with an integrated display is being considered for future development. Post a comment if you would like that.

** BLE - Bluetooth Low Energy.