MODEL AT3
3 – 7
2.c. The "Threshold" value needs to be set above the noise yet not so high that
echoes are not seen at all.
NOTE
: For concentration measurement, a good rule of thumb is to set the
"Threshold" so that the typical process concentration gives a reading of
2000 counts (the total range is 0 to 5000). This allows room for reading
much higher concentrations during an upset condition.
NOTE
: For ultra pure applications, the strategy is to set the "Threshold" just
above the noise level so that everything is seen. Of course this means
the instrument will saturate at a relatively low concentration
2.d. The “Window Posn”·is used to set the window in the focal point of the transducer, where the
echoes should be at their highest levels. The default value usually works well, but occasionally it
can be seen that the window does not quite match the position of the highest echoes, in which
case it is appropriate to adjust the '"Window Posn”.
2.e. Finally, the “Password" menu allows the user to set a personal 4 digit password to protect the
“Calibration” and "Measurement Setup" menus from unauthorized personnel. See Figure 3-10.
The default password is 0000.
Enter new password on following
Enter Password:
Enter new password to confirm
Enter Password:
Figure 3-10: Change Password Menu
3.
The "CALIBRATION" menu. Calibration is simply a matter of correlating the raw count level to
reflect the concentration amount in the process. See Figure 3-11. The instrument allows the user
to enter up to 16 different samples and their respective concentrations. These samples are stored
in the "SAMPLE TABLE".
Sample Table
Fit Sample Data
CALIBRATION
Cal Type: Best Fit Line
Full Plot
Partial
Coefficients
Figure 3-11: Calibration Menu.
Summary of Contents for Monitek AT3
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