HT instruments HT157 - Manual (Page 34)

HT155 - HT157
EN - 32
 With cursor flashing on the “ ” icon, press the “ ” or “ ” keys to select the
“Lock” option. Subsequently, press the “ ” key to lock the quantity data values
shown on the display. Press “ ” again to exit the “Lock” function
 With cursor flashing on the “ ” icon, press the “ ” or “ ” keys to select the
“Max” option. By subsequently pressing the “ ” key, the instrument shows the
maximum value of the quantities shown on the display, and the value automatically
updates when a higher value is detected. Press “ ” again to exit the “Max” function
13. With cursor flashing on the “ ” icon, press the “ ” or “ ” keys to access the
“Graph” graphic display of the measure (or select the “Graph” icon in the main menu).
The instrument displays the following screen:
Fig. 31: Graphic screen of 1/3 spectrum analysis
14. The screen shows the histogram of the sound pressure level associated to the
frequency spectrum whose center is reported on the x-axis, further to the indications of
the frequency weightings A, C, and Z. The minimum and maximum values on the y-axis
are determined by the measuring range selection
15. Move the cursor to the lines at the bottom of the x-axis and use the “ ” or “ ” keys to
select the spectrum frequencies and the type of frequency weighting A, C or Z. Use the
same keys to dynamically modify the measuring range. In graphic display, it is only
possible to select options Leq1s and Leq,T
16. For the remaining functions, please refer to the numerical display