Observed signal levels: none DUT1 94.7171 94.6925 94.7249 94.6970 94.7314 94.7006 averages 94.7245 94.6967 There is an obvious drift with time that we can see when subtracting the averages: -0.0074 -0.0042 0.0005 0.0003 0.0069 0.0039 There is an obvious drift with time. The drift between two measurements of the same noise level is about 0.0050 dB which means that the measurements of DUT1 are too high by 0.0025 dB since they are all half an interval later than the measurements of none. The insertion loss of DUT1 is therefore: IL = 94.7245 - 94.6967 + 0.0025 = 0.0303 dB Correcting for the frequency drift we have 94.7171 94.6900 94.7199 94.6895 94.7214 94.6881 Standard deviations 0.0022 0.0010 RMS sum of deviations 0.0024 The standard error in the insertion loss is then 0.0014 since it is based on 3 measurements The measurement error (3 sigma) would then be 0.0042 dB. Errors are estimated from too few data points so the error estimation for this measurement is uncertain. |