Hach-Lange POLYMETRON 9240 Operator Manual - Manual (Page 71)

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Operating Instructions
5.3.2 Grab sample
Note: It is recommended that the grab sample should have a concentration of > 10 ppb and should be at
the same temperature as during calibration for better accuracy. Under these conditions, measurement with
manual introduction gives 5% accuracy from 10 ppb to 10 ppm at a temperature which is within ± 5 °C of the
temperature during calibration.
Similar to the verification process, this option allows
measurement of a sample of your choice.
Before starting this process, ensure you have a sample of
approximately 200 mL to measure.
The first step of this cycle allows the reactivation of the
electrode. The message SENSOR ACTIVATION is displayed.
Select Yes to reactivate the sensor. Select No if time is more
important than accuracy.
The reactivation process is automatically followed by a rinsing
of the overflow vessel and measuring cell using the process
sample.
A progress bar (regularly refreshed) is displayed showing the
time remaining to complete the process.
Flow rate and measurements are also displayed.
Upon completion of the rinsing step, the analyzer is ready for
the first manual step in the cycle.
Place the lid of the overflow vessel on the side and pour
approximately 200 mL of the solution into the overflow vessel,
as prompted on screen. Manual introduction is complete when
the sample overflows at the back of the overflow vessel.
Place the lid back on top of the overflow vessel and select OK
to start the measurement.