Sievers TOC 800, Operation And Maintenance Manual

Page: 169 / 255

Ionics Instruments

2004 Page 9-11 DLM 30007-08 Rev. A
6. From the GRAB SAMPLING menu, use the
arrows
( or )
to scroll
to START and press ENTER. The analyzer will make 10
measurements. When the measurements are finished, the average
TC value and relative standard deviation for the last three TC
measurements of the TC Calibration Standard will be displayed.
7. Record the average value from the last three TC measurements of
the TC Calibration Standard, as shown on the measurement display,
on the Calibration Worksheet.
The accuracy of the analyzer is ±3% of the TC concentration. For example,
for the measurement of a 25.1 ppm TC standard (25 ppm KHP + 0.1 ppm TC
background from water), the average TC values should fall between 24.3 and
25.9 ppm. Calculate the upper and lower limits of the adjusted standard
concentrations. If the average value for the last three TC runs is within ±3% of
the TC concentration of the TC standard, the TC channel of the analyzer is
properly calibrated and no changes are necessary for the TC Calibration
Constant. If the average value for the last three TC runs is not within ±3% of
the TC concentration, recalibrate the CO
2
sensors as follows in Part Three.
Additionally, the CV (relative standard deviation) for the last three
measurements should be less than 3%. If this value is greater than 3%, repeat
the measurements with a new standard. The CV value appears on the
analyzer’s printout, or can be calculated as follows. Record the values on the
Calibration Worksheet.
1
2
) (
Deviation Standard
−
∑ −
=
n
x x
set a in ts Measuremen of Number n
Average x
Result x
of Sum
=
=
=
∑ =
100 x
Average
Deviation Standard
(RSD) Deviation Standard Relative
=