Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 149)

<12. OPERATION OF DO (Dissolved Oxygen)>
12-9
IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
12.5 Trend graphics
Pressing on the Zoom display changes the display to a graphical mode in which the
average measured value is shown on a time scale. The “Live” value is also digitally displayed in
a text box. The time scale (X-axis) and the primary value scale (Y-axis) are set in the “DISPLAY
SETUP” menu (Section 13.7.2).
The screen displays the trend of up to 41 averages of the measurement for each time interval.
The FLXA21 samples the measurements every second. The trending graphic also shows the
maximum and minimum measured values in that interval.
For example, if the time scale is set to 4 hours, then the trend is shown for 4 hours prior to the
actual measurement. Each point on the trend line represents the average over 4Ч60Ч60/41 =
351 measurements (seconds).
NOTE
Updating the trend screen setup resets the current trend graph and starts a new one.
12.00
8.40
5.60
2.50
12:00 12:20 12:40
9.10mg/L
Minimum
Maximum
Average
Time
Tag:
Measurement value (mg/L)
FLXA21-DO Oxygen1
Current process value
Max. and min. values on this display
Figure 12.8 Trend screen
The 1st display item data on the Main display is shown as a graph. Touching any point on the
display changes the display to the 2nd display item data (and to the 3rd display item data if set)
and then returns to the Main display.
DO
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