In our daily life during debugging and test the circuit , when initialing the oscillograph, always we press the “ AUTOSET ” for short.
But , Do you ever need to measure the very low frequency wave? For instance: lower than 2 Hz , or lower than 1 Hz? In this situation, the botton of “ AUTOSET ” has no use . the text below will teach you how to measure the very low frequency.
We will measure a sine wave which frequency is 0.7 Hz, and the Vpp is 3.5( we suppose we don`t know what kind wave it is) .
Then let`s press the “ AUTOSET ” push button , what happened? Let us lood at the wave displayed in the oscillograph .
What kind of wave is it ? It is nothing ! Don`t confuzed by the phemomenon, because the frequency is too low now ,so the sampling of the oscillograph is not high enough, so it looks as if it is nothing. Now ,let me modify the button of “ SEC/DEV ” , decrease the value of sec/dev .and let us see the wave again:
Now we can see the wave now ,it is sine wave ! Hehe, if you are careful enough, you will see that there is some area black on the screen . this is relative to the mode of scanning .
Is it simple?