Calibrate The Field Meter; Calibration Memory; Test A Water Sample; Correlated Values - Abb Uvitec Uv254 Operating Instructions Manual

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...4 Operation guide

4 .3 Calibrate the field meter

1 If your meter has a battery pack, switch the battery pack to
the On position.
2 Plug in the power cord and press Power to turn on the field
meter. After 90 seconds, the display will read Ready.
3 Make sure that the quartz cuvette is not in the test chamber.
4 Press the Calibrate button. The display will read Insert
Cuvette with DI water.
5 Ensure the outside of the cuvette is clean and dry.
6 Insert the cuvette containing DI water ensuring the black dot
on the cuvette is aligned with the circle next to the test
chamber.
7 Display will read 100.0 when in UVT mode or 0.000 when in
UVA mode. The field meter is now calibrated.
Note:
We recommend to calibrate the field meter again after you
replace the UV lamp or use a new cuvette for sampling.
For best results, calibrate the field meter every month using DI
water, especially when the field meter is being used weekly.

4.3.1 Calibration memory

The UviTec UV254 field meter keeps its calibration settings in
its memory. This feature eliminates the need to zero the field
meter before each individual water sample being tested (even
after powering the field meter off and on). Users may choose to
periodically check the field meter's calibration by using a DI
water sample (or another water sample equivalent to 100 %
UVT/0 UVA). If the accuracy of the calibration is not within
0.5 % UVT/0.003 UVA, refer to "Calibrate the field meter" on
page 6.
Note:
It is not necessary to send the field meter back to ABB for
verification of calibration. When calibrating, use 100 %
UVT/0 UVA water (DI water). Calibration can also be verified
with an IN-SPEC solution that has a known UVT/UVA value.
®
Contact ABB for more information about IN-SPEC.

4 .4 Test a water sample

1 If your field meter has a battery pack, switch the pack to the
On position.
2 Plug in the power cord and press Power to turn on the field
meter. After a 90 second warm-up time, the display will read
Ready.
3 Make sure that the quartz cuvette is not in the test chamber.
4 Press the Compute button. The display will read Insert
Cuvette with Test Water.
5 Make sure that the outside of the cuvette is clean and dry.
6 Insert the cuvette containing the water sample to be tested.
Align the black dot on the cuvette with the circle next to the
test chamber.
7 The display will show the computed UVT or UVA.
8 To do another test, remove the cuvette from the test
chamber. Rinse the cuvette twice before inserting the new
sample. Repeat steps 4 thru 6.
9 Clean and dry the cuvette thoroughly before reinserting into
the field meter for storage.
10 Press Power to turn off the field meter.

4 .5 Correlated values

An estimate of the value for a water quality parameter can be
made using the UVA data, provided that a good linear
relationship exists between the parameter and the UVA. This
requires collecting samples with known UVA values and
sending these samples to a lab for analysis using a reference
method to establish the parameter concentration e.g., mg/L
TOC.
To find the linear relationship, you need a spreadsheet to graph
parameter values versus UVA values i.e., TOC vs. UVA in this
example. Microsoft Excel
® ®
graph the data. When the data plot is complete, the slope of the
regression line (also called the trend line) that goes through the
data points indicates the ratio between TOC and UVA. Moving
forward, an estimation of TOC can be made for a sample by
multiplying the UVA value of the sample by this ratio.
Over time, if you keep adding more reference lab data to your
TOC vs. UVA plot, the accumulation of many data points will
build a more accurate estimate of the TOC.
Note:
If processes change, the ratio you are applying might not be
reflective of current conditions.
is one of the tools you can use to