PULSAR MEASUREMENT
17
CALIBRATION
Press
or
to position curser at Calibration menu, and
to enter. Use
or
to position cursor before each menu item and
to enter. When settings are
completed press
to store and
again to return to the Main Menu.
Mode
Displays the Mode which was selected in the Units/Mode
menu. This is read-only.
20mA
Press
then
or
to change the numbers and decimal
point position. Use this menu to set the corresponding flow
rate that will be represented by 20mA analog output. If
maximum flow is unknown, enter an estimated flow rate and
observe actual flow to determine the correct maximum
value. Any velocity or flow rate up to +40 ft/sec (12.0 m/sec)
may be selected.
4mA
Press
then
or
to set the flow rate corresponding to
4mA analog output. This setting may be left at zero or can
be raised to any value less than the 20mA setting, or
lowered to any velocity or corresponding flow rate down to
-40 ft/sec (-12 m/sec).
LOS Time
Use LOS Time to suppress intermittent loss of signal.
Example: systems with high concentrations of undissolved
gasses will cause fluctuations in signal strength when the
gasses move past the ultrasonic signal. If a complete loss of
signal is experienced, the TTFM 6.1 will hold the last valid
reading for the duration of the LOS Time. If the signal
strength returns before the LOS Time is expired, because the
ultrasonic signal is no longer being impeded, the meter will
return to normal operation automatically. If signal strength
does not return after the LOS Time has expired, then the
meter will report zero flow on the LCD display and outputs
and produce a Low Signal alarm. Default LOS Time is 30
seconds, and the value can be set between 0 and 99
seconds.
Min Flow
Flow rates below this setting will be displayed as zero flow.
Default flow rate is ~ 0.1 ft/sec for the pipe size
programmed in the Setup menu.
--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
