The gauge is designed for measurement of the dose rate and activity of brachytherapy applicators ¹⁰⁶Ru and ¹²⁵I for irradiation eye tumor (cancer). The investigated radiation source is placed in a water filled container equivalent to eye tissue. The source radiation is measured with ø2x2 mm plastic scintillator. The container with the source measured moved in vertical and horizontal direction with a micrometer screw. To measure the activity of the source, the probe is raised to the height allowing treating the source as a point source of 250 mm and the container is emptied from the water. A removable radiation collimator ø2x23 mm permits for measurement of variation of source activity upon its surface. Measuring process is carried out under the microprocessor supervision. Displayed gauge functions and instructions make handling of the gauge friendly to the user. Automatic gain control of photomultiplier tube ensures stable operation within long period of time. The measuring results are stored in the gauge memory and are sent to external computer by means of a serial port.