In-Situ TROLL 9500 Operators Manual - Manual (Page 132)

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TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
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A screen similar to the one shown below is displayed.
12. If you are performing performing a single-point calibration, enter
the value of the calibration standard (NTU). For a multi-point
calibration, the value of the first solution will be displayed.
13. When the sensor is situated in the calibration medium, select Run
to begin the stabilization.
The display will continuously update as readings are taken and
compared against the stabilization criteria.
s
NOT TESTED is displayed until you begin the calibration by
selecting Run.
UNSTABLE indicates the sensor response does not meet the
criteria for a valid calibration point.
NOMINAL indicates the sensor deviation meets early stabiliza-
tion criteria.
The Accept button becomes available when nominal stability is
achieved. You may accept the early value, or wait for complete
stability. If you accept the early value, the calibration point will
be designated “USER SET” in the calibration report. (For more
on calibration reports, see “Calibration History” in Section 10.)
STABLE is displayed when the readings have stabilized suffi-
ciently to take a valid calibration point. The calibration proceeds
automatically to the next screen.
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readings.
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14. If doing a one-point calibration, go to step 17.
For a multi-point calibration, the Wizard returns to the screen
shown at step 13 and waits for you to situate the probe in the next
calibration solution and click Run.
15. Discard the first solution, rinse the beaker and the front end of the
instrument thoroughly, wipe off excess water, refill the beaker with
the second solution, and insert the MP TROLL 9500 as before.
16. Select Run to begin the stabilization for the second calibration
point. Status indicators and controls are the same as for the first
calibration point (step 13).
Again wait for stabilization, dump, rinse, dry, refill, Run, as many
times as necessary to collect a stable calibration point in each
solution.
17. The final screen shows the sensor slope and offset calculated dur-
ing the calibration process (or the default settings if you selected
that option at step 7). A slope and offset will be shown for each
calibration point.
“Pivot” designates the point at which the slope characteristics
change with a multi-point calibration. The correct slope for the
turbidity values being monitored will automatically be applied.
18. Select Finish to program the sensor with the newly calculated
calibration coefficients.
TIP: You can look at the calibration report right after
calibrating, or at any time. See “Calibration History” in
Section 10 for details.
SECTION 18: TURBIDITY