The Spectrum Power Calculations utilise Volts Squared (V^2). This can cause issues for small signals at the low millivolt (mV) or microvolt (uV) level, as the voltage is squared as part of the Power calculation - therefore signals smaller than 1V will be reduced in size.
For example 0.01V(10mV)^2 = 0.0001V - the Spectrum Channel calculation shows only up to 3 decimal places, so 0.0001V^2 would appear as 0.000V^2, and by default the Data Pad Spectrum Power Values only show 2 Decimal places:

To resolve this issue, you need to re-format the Data Pad Column to show more decimal places. See the attached solution AD-1004 for information on how to do this.
Note that the decimal points of the Power Channel Calculation cannot be amended. If you need to extract the numerical values, use Multiple Add to Data Pad.
For example 0.01V(10mV)^2 = 0.0001V - the Spectrum Channel calculation shows only up to 3 decimal places, so 0.0001V^2 would appear as 0.000V^2, and by default the Data Pad Spectrum Power Values only show 2 Decimal places:
To resolve this issue, you need to re-format the Data Pad Column to show more decimal places. See the attached solution AD-1004 for information on how to do this.
Note that the decimal points of the Power Channel Calculation cannot be amended. If you need to extract the numerical values, use Multiple Add to Data Pad.