The Portable Water Hardness Meter is equipped with a state-of-the-art solid-state ion-selective electrode and features a convenient LCD display. Its accuracy is enhanced through manual temperature calibration. Additionally, the device allows for seamless data transfer to a computer via a USB communication interface. Within its intuitive system menu, users can customize seven key parameters, encompassing calibration point count, stability criteria, the hold function, and automatic power-off settings. Moreover, a built-in stability indicator keeps users informed about the current measurement status, ensuring reliable and user-friendly operation. This portable water hardness meter combines precision and convenience, making it an indispensable tool for water quality assessment in various applications.