TTFM 6.1 INSTRUCTION MANUAL
18
CALIBRATION (cont.)
Damping
Mode
Choose between OFF, FIR (Default), or LOW PASS.
When measured flows are outside the Window of the
running average, the FIR filter will reduce the damping
average so that a fast response can be made to the sudden
change in flow rate.
The LOW PASS filter will ignore measured flow rates outside
the Window, while holding the running average, until there
are enough data points outside the Window to cause a step-
response to the new measured value.
While measured flows are within the Window of the running
average, both the FIR and LOW PASS filter behave the same.
Percent
Higher percentages increase the number of measurements
which are averaged together to produce a stable flow
reading. Higher percentages also increase the time it takes
for the meter to make a step-response to the measured flow
rate outside the Window in the LOW PASS Mode.
Window
Defines the Window around the running average, in units of
Velocity set in the Units/Mode menu. Measurements made
inside the Window are added to the running average, and
measurements outside the Window effect the response of
the meter as described in the Mode section.
Cal
Constant
Calibration constant defined when the TTFM was calibrated
at the factory.
Press
to return to Menu Selections.
--Calibration-------
Mode
Flow
20mA
500.00 USG/m
4mA
0.00 USG/m
LOS Time
10 sec
Min Flow
4.00 USG/m
Damping
Mode
FIR
Percent
10%
Window
1.0 ft/s
Cal Constant
1.00
