Spirax Sarco UTM20 Series - Page 54

IM-P505-02-US Issue 1
54
UTM20 Series Ultrasonic Transit-time Flowmeters
Fig. 48 Bad data (rejection)
The flow rate is again outside the original ±10% Hysteresis window, but the data exists for a time period
greater than the Bad Data Rejection window In this instance, the meter interprets the data as a new
valid flow rate and moves the Hysteresis window to correspond with the new established flow rate
Fig. 49 New valid flow data
150
110
100
90
50
0
Flow Within
Hysteresis Limit
±10% Hysteresis
Limit
Flow
3 Samples Outside
Hysteresis Limit
Bad Data
Rejection
Window
Sample
limits
150
110
100
90
50
0
Flow Outside Original
Hysteresis Limit
New
±10% Hysteresis
Limit
Flow
4 Samples Outside
Hysteresis Limit
Bad Data Rejection
Window
Old ±10% Hysteresis
Limit