Yokogawa 202 Field Mounting Rate Totalizer User Manual
Page 18
Operation
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3.6 FREQUENCY CUTOFF
A frequency cutoff can be programmed below which flow rate is not registered.
Input frequencies at or below the cutoff are totalised, however, the rate is
displayed as zero.
The frequency cutoff has a default value of 0.25Hz. The cutoff should be left as
0.25Hz unless the flowmeter in use has a lower frequency.
Note that a low cutoff frequency will result in a correspondingly low response of
flow rate update. For example, if the cutoff is set to 0.01Hz the 202D will
continue to display the flow rate for 100 seconds even if the signal stops. This is
because a cutoff frequency of 0.01Hz means that the time interval between signals
is 100 seconds (period = 1/frequency). Therefore, the Model 202D must wait 100
seconds before it can determine that the flow has actually stopped.