Contents - Index - Previous - Next


Measurement Accuracy

Frequency Accuracy:
The frequency accuracy depends directly on the accuracy of the sampling clock on the DT-9800 device.  This is typically a fraction of a Hertz (Hz).  

Amplitude Accuracy:
The DT-9800 device produces calibrated voltage values.  Consult the specifications provided with your specific DT-9800 data acquisition module for the tolerances.  The specific transducer accuracy must be taken into account as well.

Octave Scaling Accuracy:
Historically, spectrum analyzers have utilized analog filters for each band and standards (ANSI S1.11-2004) have been developed which specify the performance of these filters .  SpectraPLUS-DT uses a  Fast Fourier Transform (FFT) to compute the spectral data and then derives the octave data.  This algorithm uses the same ISO center frequencies and bandwidths as analog instruments; however, the FFT filtering method produces much steeper "shoulders".  These digital filters meet or exceed the performance of traditional analog filters.  

Dynamic Range:
The theoretical dynamic range of the system is as follows:
  8 bit sampling precision = 48 dB
16 bit sampling precision = 96 dB
24 bit sampling precision = 144 dB
The actual dynamic range achieved is always less due to electrical noise and other factors.

See also:  Scaling, Settings , Calibration