YSI ADV6600 - Manual (Page 75)

Section 4. Calibration and Diagnostics
ADV6600
Y S I
Environmental
Page 65
RHODAMINE WT LIQUID (Part # 70301027). As purchased, the solution is approximately 20 %
rhodamine WT by weight, i.e., 200 g/L.
1. Accurately weigh 0.500 g of the 20 % rhodamine concentrate. Quantitatively transfer the viscous
liquid to a 1000-mL volumetric flask.
2. Fill the flask to the top graduation with purified water. This solution contains 100 mg of
rhodamine WT per 1000 mL of water.
3. Accurately transfer 1.0 mL of the solution prepared in the above step to a 1000 mL volumetric
flask.
4. Fill the flask to the top graduation with purified water. Mix well to obtain a solution that is 100
ug/L (0.10 mg/L) in water (a 1000:1 dilution of the concentrated solution).
5. Store the concentrated standard solution in a darkened glass bottle in a refrigerator to retard
decomposition. The dilute standard prepared in the previous step should be used within 5 days of
its preparation.
When rhodamine WT standards are required in the future, perform another dilution of the concentrated
dye solution after warming it to ambient temperature. Our experience has indicated that the
concentrated solution that has been kept at cold temperatures is much more stable than the dilute
solution stored at room temperature.
Calibration
When selecting to calibrate Rhodamine, there will be a choice of a 1-point, 2-point, or 3-point
calibration.
A 1-point calibration is used to zero the rhodamine sensor in 0 ug/L standard.
A 2-point calibration is used if the range of the rhodamine concentration for the study can be
predicted. One of the standards must be 0 ug/L. For most measurements, an appropriate choice of
standards is usually 0 and 100 ug/L.
A 3-point calibration assures maximum accuracy over the entire range of 0 to 200 ug/L. One of the
standards must be 0 ug/L. Two additional standards of the user’s choice are also used.
Calibration:
1. With the ADV6600 in an upright position, place the correct amount of rhodamine WT standard
in a clean, dry or pre-rinsed calibration cup. Immersed the probe end of the ADV6600 into the
solution. Allow at least one minute for temperature equilibration before proceeding.
2. From the Calibrate menu, select Optic Rhodamine to access the rhodamine WT calibration
choices and select either a 1-point, 2-point, or 3-point calibration.