Hach DR/850, Procedures Manual, Page: 50 / 460

50
CHEMICAL ANALYSIS INFORMATION
, continued
Figure 11 Logarithmic Calibration Curve
To convert %T readings to concentration, prepare a table such as Table 7
and select the appropriate line from the “%T Tens” column and the
appropriate column from the %T Units columns. The %T Ten value is the
first number of the %T reading and the %T Units value is the second
number of the %T reading. For example, if the instrument reading was
46%, the 40 line in the %T Tens column and the 6 column in the %T
Units would be selected. The cell where these two intersect (0.78 mg/L) is
the iron concentration of the sample.
2.40 1.60 1.80 0.40 2.00 0.20 2.20 0.00
10
20
30
40
50
60
80
100
0.60 1.40 1.20 1.00 0.80
PERCENT
TRANSMITT
ANCE
mg/L IRON