Color measurement, Measurement notes – Hach-Lange 2100 AN Laboratory Turbidimeter User Manual User Manual
Page 31
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 30.
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
measurement and calibration procedure
on page 30.
• 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
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
on page 21.
• Refer to
on page 25 for more measurement
notes.
English 29