29
About the Accuracy/Calibration
of the eXact Micro 20 System
eXact
®
Strip Micro
DPD–1 Accuracy
All tests have been calibrated using certified reference standards and standard analytical
spectrophotometric methods. The algorithms in the software reflect the best correlation of the eXact
®
Micro 20 Systems against the AWWA, US EPA , DIN, and ISO reference test methods for chlorine.
Studies show that the eXact
®
Micro 20 System repeatedly agrees with an EPA Compliant reference
method greater than 99% (R2= 0.99948, 0 – 5.00 ppm – see below). The eXact
®
Micro 20 Advanced
Photometric System has been factory calibrated for your convenience. You can expect the fixed
calibrations in the meter to be valid for the life of the meter because of the quality, Long–Life LED,
the photo
cell
, and the software as written into the meter. This is why the meter comes with a 2–Year
Warranty.
Free Chlorine results are compared using the eXact
®
Strip Micro CL (DPD–1) with the eXact
®
Micro
20 Meter in MENU CL and Hach
®
DR890 Colorimeter in Program 9 and Program 12 using Hach
®
powder pillows.
NOTE:
Values reflect current concentrations as found at time of manufacture and may change with consecutive lots.
Assigned Value for Ready Snap
®
Solution
Ready Snap
™
Lot
Parameter
Desired
Value
Acceptable
Value
Menu
Red Dye #505
Free Chlorine
1.72 ppm
1.70 - 1.74 ppm
CL1
1
Red Dye #22515
Free Chlorine
1.01 ppm
0.95 - 1.10 ppm
CL1
1
Blue Dye #506
Transmission
22.0 %T
21.0 - 23.0 %T
TR2
7
R031517
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DR890
Micro 20
0.00
0.00
0.23
0.23
0.58
0.59
1.01
1.02
1.46
1.53
2.1
2.06
2.7
2.83
3.5
3.63
4.1
4.25
4.4
4.65
5.2
5.31
6.1
6.09
