79
Phone:(910) 392
‐
2490
Fax: (910) 392
‐
2123
416 Landmark Drive
Wilmington, NC 28412
www.easterninstruments.com
CAL.FILTER
CAL.FILTER is the Filter page. Access this screen by pressing the FILTER Bu on on the TOP.CAL
page a er pressing the CAL Bu on from the TOP page. This page is for selec ng the number of
points used in the 4
‐
20mA moving average
fi
lter. The formula for a moving average
fi
lter is
shown below. Press one of the Filter Bu ons to select the desired me increment for the
fi
lter.
For example, a me increment of 1 second will
fi
lter (or average) 200 samples of the input sig
‐
nal to create the 4
‐
20mA
fi
ltered output signal. This is because the transducer input sample
rate is 200 samples per second. The 4
‐
20mA output signal is updated at the same sample rate
as the input signal. However, the output signal will be delayed by the selected me. The mov
‐
ing average
fi
lter can also be turned o
ff
from this screen.
Moving Average Filter
The moving average is a very common
fi
lter in digital signal processing. Despite its simplicity,
the
fi
lter is op mum at performing the common task of reducing random noise while retaining
a sharp step response.
FILTER BUTTONS
FILTER BUTTONS