YSI 6 series User Manual page 53

Sondes Section 2
Before making any field readings, carefully read Section 5.16, Principles of Operation to better
understand the practical aspects of BGA-PC fluorescence measurements.
To begin the calibration, place the correct amount (see Tables 1-8 above) of clear deionized or distilled
water into the YSI clear calibration cup provided. Immerse the sonde in the water. Input the value 0
cells/mL at the prompt, and press Enter. The screen will display real-time readings that will allow you to
determine when the readings have stabilized. Activate the wiper 1-2 times by pressing 3-Clean Optics as
shown on the screen to remove any bubbles from the sensor. After stabilization is complete, press Enter to
"confirm" the calibration and then, as instructed, press Enter to return to the Calibrate menu. Note that
because the range of the BGA sensors in cells/mL is large, the readings may appear to be somewhat noisier
during the calibration procedure than for other 6-series sensors. Variations of +/- 400 cells/mL for the zero
point can be observed with a properly functioning sensor since this value is only 0.2% of the range.
Thoroughly rinse and dry the calibration cups for future use. For additional information related to
calibrating the BGA-PC sensor, see Section 5.16, Principles of Operation.
Note that the 1-point calibration of the BGA-PC sensor in cells/mL will also zero the PC RFU (Relative
Fluorescence Units) parameter which is in units of percent of the full scale of the sensor. Users may wish
to activate PC RFU in the Report menu and simply use this parameter to determine BGA-PC events until a
good correlation between the observed cells/mL value and the value determined from laboratory analysis
has been established.
BGA-PE 1-POINT
Select Optic X BGA-PE - from the Calibrate Menu, and then 1-1 point.
NOTE: This procedure will zero your fluorescence sensor and use the default sensitivity for calculation of
phycoerythrin-containing BGA in cells/mL, allowing quick and easy fluorescence measurements that are
only semi-quantitative with regard to BGA-PE. However, the readings will reflect changes in BGA-PE
from site to site, or over time at a single site.
To increase the accuracy of your BGA-PE measurements, follow the 2-point calibration protocols outlined
in Section 2.9, Sonde Menu.
Before making any field readings, carefully read Section 5.17, Principles of Operation to better
understand the practical aspects of BGA-PE fluorescence measurements.
To begin the calibration, place the correct amount (see Tables 1-8 above) of clear deionized or distilled
water into the YSI clear calibration cup provided. Immerse the sonde in the water. Input the value 0
cells/mL at the prompt, and press Enter. The screen will display real-time readings that will allow you to
determine when the readings have stabilized. Activate the wiper 1-2 times by pressing 3-Clean Optics as
shown on the screen to remove any bubbles from the sensor. After stabilization is complete, press Enter to
"confirm" the calibration and then, as instructed, press Enter to return to the Calibrate menu. Note that
because the range of the BGA sensors in cells/mL is large, the readings may appear to be somewhat noisier
during the calibration procedure than for other 6-series sensors. Variations of +/- 400 cells/mL for the zero
point can be observed with a properly functioning sensor since this value is only 0.2% of the range.
Thoroughly rinse and dry the calibration cups for future use. For additional information related to
calibrating the BGA-PE sensor, see Section 5.17, Principles of Operation.
Note that the 1-point calibration of the BGA-PE sensor in cells/mL will also zero the PE RFU (Relative
Fluorescence Units) parameter which is in units of percent of the full scale of the sensor. Users may wish
to activate PC RFU in the Report menu and simply use this parameter to determine BGA-PE events until a
good correlation between the observed cells/mL value and the value determined from laboratory analysis
has been established.
YSI Incorporated Environmental Monitoring Systems Operations Manual 2-47