An automated device is designed to measure the density of a liquid material using hydrostatic pressure method. A low cost pressure sensor is calibrated and used to get highly accurate readings. The calibration is done by measuring the pressure values vs. the generated voltage signal. The calibration has been challenging due to the low accuracy of the sensor but proved to be highly effective in applications. The interface is developed using a microcontroller, motor drives, analog to digital converters and sensors. The device is designed to get several readings automatically by changing the positions of the device/liquid column heights to increase the accuracy. Also the device can be programmed to measure the real time density of a liquid continuously. The readings were analyzed and averaged by a software developed in python language. The instruments accuracy was tested against 3 liquid types, water, coconut oil, kerosene oil, and showed a low error (0.007%, 0.001%, and 0.002% respectively) compared to the readings of a standard Pycnometer. The low error percentages confirm the accuracy of the device and the effectiveness of the sensor calibrations.

A low-cost, automated surface tension analyzer was designed and developed based on the maximum bubble pressure method. The system measures the pressure required to form air bubbles through a capillary immersed in a liquid, allowing the surface tension to be determined from the pressure–depth relationship. The experimental setup integrates a pressure sensor solenoid valve, stepper-motor-controlled depth stage, and data acquisition unit. A Python-based software interface was developed for real-time signal processing. Validation was performed using several Newtonian liquids, including water, toluene, methanol, ethanol, and n-hexane, with experimental results showing strong agreement with theoretical values yielding a maximum deviation below 2%. The developed instrument demonstrates excellent repeatability and sensitivity confirming its suitability for research and industrial applications.