Select Filter - AEMC DTR 8510 User Manual

4.3.6

Select Filter

1. From the top level of Configure Instrument, press the ▼ or ▲ key until
Select Filter appears on the display, then press ENTER.
2. Select Fast, Normal or Slow using ▼ or ▲ and press ENTER. The
display will return to Configure Instrument > Select Filter.
NOTE: The DTR
measurement, depending upon the external electrical noise. These are
sophisticated digital filters in the design which offer maximum noise
rejection for repeatable measurements.
Digital Filters:
The digitization of signal is done with Sigma-Delta (Σ-Δ) modulator. The
output is a high frequency bit stream which is fed to a digital filter. The
filtering of signal is performed with sophisticated sinc (Sinx/x) filter. The
primary function of the filter is to remove the quantization noise introduced
during the modulation process.
The filter limits the band of the allowed frequency to significantly lower than
one-half of the frequency of the modulator itself. This reduces the 1-bit
output of a comparator in a band-limited, very low noise output. The cut-off
frequency and the decimated data rate are appropriately programmed in
the internal registered and the output is arithmetically averaged to provide
an accurate final answer.
High decimation results in lower noise but at a slower throughput rate. The
calculation of arithmetic mean is a quick process at high clock speeds of
the microprocessors.
The DTR 8510 improves the quality of measurements in the following
®
ways:
(1) Low noise electronics
(2) Shielded electronics and cables.
(3) Differential measurements to reduce common-mode effects.
(4) Ratiometric calculations to reduce dynamic errors.
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Shop for AEMC products online at:
Figure 4-17
8510 offers the user a choice of three digital filters for
®
Digital Transformer Ratiometer DTR
ShopAEMC
www.
Model 8510
®
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