Promax -12 User Manual page 15

The TILT operating mode shows on the display, both graphically and
numerically, the level difference between any four frequencies,
previously defined as pilot channels, in order to obtain information
about band equalisation. This function can be applied to the forward
band and to the return path, independently.
This is a multifunctional key. For one hand, it measures the HUM
frequency and value (%). HUM is a low frequency modulation that
affects carriers and produces a characteristic buzzing in both image
and audio, especially in analogue signals. On another hand, it
automatically identifies the voltage type (DC or AC) at the input and
the frequency in case of alternating voltage.
Access the configuration parameters for the selected function and the
global parameters for the equipment (more details in the next section).
January 2015 3-9