Hach-Lange FILTERTRAK FT 660 sc User Manual - Manual (Page 26)

95% confidence intervals are very high. The error was primarily traced to
the lot-to-lot variability in the preparation and subsequent measurement
for each standard.
From the data collected in this study, it was identified that 1.0 mg/L
kaolin is equivalent to 1.0 NTU turbidity.
Table 5 Summary: Correlation between kaolin mg/L values and
NTU turbidity values on the FT660 sc
Standard
value
(theoretical) in
mg/L kaolin
Averaged
turbidity in
NTU for
kaolin lots A
and B
Pooled
standard
deviation
for kaolin
lots A and
B
Predicted
95%
confidence
range +/-NTU
from the
averaged
kaolin value
Percent
uncertainty at
95%
confidence
0.10 0.098 0.0273 0.0546 55.6%
0.20 0.169 0.0594 0.1187 70.3%
0.41 0.339 0.0239 0.0479 14.1%
0.80 0.754 0.0504 0.1009 13.4%
1.01 0.999 0.0534 0.1069 10.7%
1.20 1.186 0.0414 0.0829 7.0%
1.59 1.573 0.0870 0.1740 11.1%
1.80 1.850 0.0487 0.0974 5.3%
2.10 2.065 0.0480 0.0960 4.6%
2.40 2.338 0.0466 0.0932 4.0%
Table 6 Statistical summary of the correlation between mg/L kaolin
and NTU
Slope Correlation
coefficient
Averaged % error
(over the full range)
Pooled standard
deviation for kaolin lots
A and B
0.9932 0.9990 0.6804
Replacement parts and accessories
Note: Product and Article numbers may vary for some selling regions. Contact the
appropriate distributor or refer to the company website for contact information.
Replacement parts
Description Quantity Item no.
Cover, bubble trap 1 5201200
Drain plug for the FT660 sc 1 4411600
Body of the FT660 sc 1 5230300
Head assembly of the FT660 sc * 1 6016100
Sensor cap 1 5791100
* Only compatible with 5230300.
Accessories
Description Quantity Item no.
Aperture plate 1 6735600
Cleaning brush 1 68700
Calibration kit
(includes the calibration body, 1 L of
800 mNTU StablCal Standard and a funnel)
1 5236400
Deionized (demineralized) water 1 L 27256
24 English