Hach 2100AN - Color Measurement; Measurement Notes

7. Slowly put 250 mL of
the sample in the inlet
reservoir.
8. After the sample
flow stops and the
display stabilizes, read
and record the value.
Note: To print or send
(via RS232) a
measurement record,
push PRINT.
Color measurement
Measurement notes
For the best accuracy and reproducibility:
• Calibrate the instrument for color measurement using a blank solution
(deionized water) and a known standard (15 or 500 CU) as shown in
Color measurement and calibration procedure on page 31.
15 CU standard—Use for calibration when low-color concentrations
are to be measured. To make a 15 CU standard, add deionized water
to 15 mL of the 500 CU standard from Hach until 500 mL. A flow cell
must be used to do a calibration with a 15 CU standard.
500 CU standard—Use for calibration when color concentrations
greater than 30 CU are to be measured. Use the 500 CU standard
from Hach for the 500 CU standard.
• Set the zero reference point before measurement when a
measurement is not taken for several hours as shown in Color
measurement and calibration procedure on page 31.
• Color, transmittance and absorbance measurements use the same
zero reference point. Color, transmittance and absorbance can be
measured on a single sample after setting a zero reference point in
one of the three modes.
• Use a flow cell for measurements. A flow cell is necessary to get the
accuracy and reproducibilty specifications shown in Specifications
on page 5. Use of a Flow Cell is especially important when low-level
color is measured.
If a flow cell is not used, match sample cells using the Transmittance
or Absorbance modes. Refer to Matching sample cells on page 22.
• Refer to Measurement notes on page 26 for more measurement
notes.
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