Agilent Technologies 83438A - Manual (Page 29)

2-9
Making Measurements
Ambient Light Suppression
5 Press REF LEVEL, and set the reference level to –10 dBm.
6 Press Amptd, LOG dB/DIV, and enter 5 dB.
7 Press MORE, CHOP On Off so that Off is underlined.
8 Press BW,Swp, SWPTIME AutoMan, and set the sweep time to 10 seconds.
9 Press MORE, MORE, adc trigger, and then ADCTRIG AC.
10 Press ADCTRIG DELAY, and enter a value of 1 ms.
11 The display should now show the proper amplitude values with the effect of the
ambient light subtracted out.