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LaMotte DC1600 Colorimeter User Manual

Page 40

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PROCEDURE

1.

Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.

2.

Select setting 6 on “Select Wavelength” knob and press “30 Second Read” button.

3.

Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This is the 100%T blank. (See

Note 2.)

4.

Remove tube from colorimeter. Use the 0.5 mL pipet (0353) to add 0.5 mL of *Sodium Arsenite Solution (4128).

Cap and mix.

5.

Use the 1.0 mL pipet (0354) to add 2 measures of *Acid-Zirconyl SPADNS Reagent (3875). Cap and mix thoroughly.

6.

Insert tube into colorimeter and press “30 Second Read” button. Record %T as soon as the reading stabilizes.

7.

Consult calibration chart to determine fluoride concentration in parts per million (ppm).
NOTE: For best results perform the test procedure on clear, colorless, fluoride free water. This reagent blank should

read 26%T. If the reagent blank reading is less than 26%T, add the difference to all subsequent unknown sample

readings. If the result is greater than 26%T subtract the difference from all subsequent unknown sample readings.

EXAMPLES:

Reagent Blank = 24%, 26 - 24 = 2. Add 2 to unknown sample result. 56 + 2 = 58%T
Reagent Blank = 29%, 29 - 26 = 3. Subtract 3 from unknown sample result. 56 - 3 = 53%T.

DC1600 FLUORIDE CALIBRATION CHART

%T

9

8

7

6

5

4

3

2

1

0

90
80
70
60

2.00

1.95

1.90

1.85

1.80

1.75

1.71

1.66

1.61

1.57

50

1.52

1.48

1.43

1.39

1.34

1.30

1.26

1.22

1.18

1.13

40

1.09

1.05

1.01

0.97

0.93

0.90

0.86

0.82

0.78

0.74

30

0.70

0.66

0.61

0.57

0.53

0.48

0.43

0.38

0.33

0.27

20

0.21

0.15

0.08

0.00

10
0

40