Xylem 6-Series Multiparameter - Manual (Page 94)

Sondes Section 2
YSI Incorporated Environmental Monitoring Systems Operations Manual 2-88
determining the BGA-PC content of algal suspensions by using standard cell counting techniques. See
Section 5.17, Principles of Operation of this manual for more information about BGA-PC standards.
Select the 2-point option to calibrate the BGA-PE probe using two calibration standards. In this case, one
of the standards must be clear water (0 cells/mL) and the other should be in the range of the suspected
BGA-PC content at the environmental site.
To begin the calibration, immerse the sonde in the 0 µg/L standard, as instructed, and press Enter. It is
mandatory that the 0 cells/mL standard be calibrated first. The screen will display real-time readings that
will allow you to determine when the readings have stabilized. Pressing Enter will confirm the first
calibration. Following the instructions on the screen, place the sonde in the second BGA-PC standard,
input the correct value in cells/mL, press Enter, and view the stabilization of the values on the screen in
real-time. After the readings have stabilized, press Enter to confirm the calibration. Then, as instructed,
press any key to return to the Calibrate menu.
For all BGA-PE calibration procedures, be certain that the standard and sensor are thermally equilibrated
prior to proceeding with the calibration
CAUTION: To be assured of the accuracy for field measurements made with your BGA-PE sensor, you
must either initially calibrate the sensor using an algal suspension of known BGA-PE content or post
calibrate your sensor in a spreadsheet by comparing the fluorescence values obtained in field studies with
those obtained by laboratory analysis for chlorophyll on grab samples collected during the field study. The
use of chemical dye standards for “calibration” of the sensor may not result in accurate correlation between
fluorescence and actual BGA-PE readings and is designed primarily to evaluate the sensor for drift. See
Section 5.17. Principles of Operation for more information on the proper calibration of your chlorophyll
sensor.
OPTIC RHODAMINE WT
When selecting Rhodamine, there will be a choice of 1-point, 2-point, or 3-point calibrations for your
rhodamine WT sensor.
The 1-point option is normally used to zero the rhodamine probe in 0 ug/L standard. Place the sonde in
clear water with no suspended solids, and input 0 ug/L at the screen prompt. Press Enter and the screen
will display real-time readings that will allow you to determine when the rhodamine readings have
stabilized. Press Enter after the readings have stabilized to confirm the calibration and zero the sensor.
Then, as instructed, press any key to return to the Calibrate menu.
Select the 2-point option to calibrate the rhodamine probe using only two calibration standards. In this
case, one of the standards must be clear water (0 ug/L) and the other should be in the range of the predicted
rhodamine concentration projected for the study. For general purpose measurements an appropriate choice
of standards is usually 0 and 100 ug/L.
To begin the calibration, immerse the sonde in the 0 ug/L standard, as instructed, and press Enter. It is
mandatory that the 0ug/L standard be calibrated first. The screen will display real-time readings that will
allow you to determine when the readings have stabilized. Pressing Enter will confirm the first calibration.
Following the instructions on the screen, place the sonde in the second rhodamine standard, input the
correct rhodamine value in ug/L, press Enter, and view the stabilization of the values on the screen in real-
time. After the readings have stabilized, press Enter to confirm the calibration. Then, as instructed, press
any key to return to the Calibrate menu.
Select the 3-point option for maximum accuracy over the entire range of 0 to 200 ug/L. As for the 2-point
procedure, one of the standards must be 0 NTU. The procedure for this calibration is the same as for a 2-