LaMotte DC1600 Colorimeter User Manual
Page 62
PROCEDURE
NOTE: Place Dispenser Cap (0692) on *Mixed Acid Reagent (V-6278). Save this cap for refill reagents.
1.
Rinse a clean colorimeter tube (0967) with sample water. Fill to the 10 mL line with sample.
2.
Select setting 4 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.
4.
Remove tube from colorimeter and pour off 5 mL into the graduated cylinder (0416). Discard the remaining sample.
5.
Return the 5 mL sample to colorimeter tube. Use graduated cylinder to measure 5 mL of *Mixed Acid Reagent
(V-6278) and add to tube. Cap and mix.
6.
Use the 0.1 g spoon (0699) to add two measures of *Color Developing Reagent (V-6281). Cap and shake tube for
approximately one minute to dissolve the powder. Wait 5 minutes for maximum color development.
7.
At end of 5 minute waiting period, press “30 Second Read” button and insert tube into colorimeter chamber. Record
%T as soon as reading stabilizes.
8.
Consult calibration chart to determine nitrite-nitrogen concentration in parts per million (ppm).
NOTE: To convert nitrite-nitrogen (N) results to ppm nitrite (NO
2
), multiply results by 3.3.
DC1600 NITRITE-NITROGEN CALIBRATION CHART
%T
9
8
7
6
5
4
3
2
1
0
100
0.001
90
0.004
0.006
0.008
0.010
0.012
0.015
0.017
0.019
0.021
0.024
80
0.026
0.029
0.031
0.033
0.036
0.039
0.041
0.044
0.046
0.049
70
0.052
0.054
0.057
0.060
0.063
0.066
0.068
0.071
0.074
0.077
60
0.081
0.084
0.087
0.090
0.093
0.097
0.100
0.103
0.107
0.110
50
0.114
0.118
0.121
0.125
0.129
0.133
0.137
0.141
0.145
0.150
40
0.154
0.158
0.163
0.168
0.172
0.177
0.182
0.187
0.192
0.198
30
0.203
0.209
0.214
0.220
0.226
0.233
0.239
0.246
0.253
0.260
20
0.267
0.275
0.283
0.291
0.299
0.308
0.317
0.327
0.337
0.348
10
0.359
0.371
0.383
0.397
0.411
0.426
0.442
0.460
0.479
0.500
0
0.523
0.549
0.578
0.612
0.653
0.702
62