4.3
How to change time on flow display?
You can choose between second, minute and hour to change time on flow display by adjusting
menu 07.
Setting the time base:
Time base
Input value
*1)
Menu reference 07
Minute XX00
Minute XX10
Second XX01
Hour XX11
*1) The “X” characters in the “Input value menu reference 07“ column are of no significance in setting
the time base.
4.4
How to find out the flow rate?
The TD 8250 commands two measuring systems to determine the flow:
duration of period measurement and
gate time measurement.
You can choose between “gate time measurement” or “duration of period measurement”
under menu
07
.
Duration of period measurement:
With the measurement of the period duration the time between two pulses is measured and
is processed with the pulse volume to the flow.
Input signals smaller than 1 Hz are not processed.
The measurement of period duration enables very fast measuring. If the flow values fluctuate
greatly the digital damping filter makes a smoothing and thereby a steadying of the flow indi-
cating unit possible.
A digital filter can be activated under the menu reference
“02”
. The higher the input value the
greater the filter effect.
Programmed value 0000: no filter effect
Programmed value 9999: maximum filter effect
Gate time measurement:
With the gate time measurement the pulses within a programmed gate time are counted and
processed with the pulse volume to the flow. The gate time measurement provides a steady
display.
Gate time can be adjusted under menu
02
in seconds. Adjustable minimum gate time is 0.1
second.
