Precision Digital PD6820 - Manual (Page 41)

PD6820 Loop-Powered Process Meter Instruction Manual
41
Low-Flow Cutoff (CUTOFF)
The low-flow cutoff feature allows the meter to be programmed so that the often-
unsteady output from a differential pressure transmitter, at low flow rates, always
displays zero on the meter. The default cutoff is zero to prevent negative readings,
but this may be overridden to allow them.
The cutoff value may be programmed from -0 to 99999. Below the cutoff value, the
meter will display zero. Selecting either square root or programmable exponent will
set the cutoff value to 0. Program the cutoff value to 0 to disable.
Input Signal Filter (FILTER)
The noise filter is available for unusually noisy signals that cause an unstable
process variable display. The noise filter averages the input signal over a certain
period. The filter level can be set to low (LO), medium (nmed), high (HI), or off (OFF).
The higher the filter setting, the longer the averaging time and so the longer the
display may take to find its final value.
The filter contains a noise filter bypass feature so that while small variations in the
signal will be filtered out, large, abrupt changes to the input signal are displayed
immediately.