Hach-Lange CL17 Instruction sheet User Manual
Page 8
CL17 Free and Total Chlorine Calibration/Verification
3.
Calculate the % difference from the calculated concentration.
This value should be within ± 5% (or between +5.0% and –5.0%).
where Y = calculated standard concentration written on the bottle, (step
).
Important Note: If %Dif is greater than 5%, rerun the test with fresh standard reagents.
Technical Notes
•
Hach Company recommends performing a verification after each reagent change.
•
Old-style CL17 analyzers without a bypass line should get 4–5 replicates from one
bottle. Leaving the bypass line open will allow only 1–2 replicates. Since the first
reading is generally discarded, 1–2 replicates is not enough. Always make sure the
bypass line is closed.
•
New-style CL17 analyzers should get 10-15 replicates from one bottle.
•
Store ampules in their cardboard cylinders in the refrigerator to reduce any adverse
effects from heat or light. Discard them if more than a year has passed from the date
on the ampule.
•
The stir bar in the old-style CL17 can be dislodged when the pressure in the bottle is
released. Result: low response, Symptom: lack of color formation, or minimal color
formation. You should see bright pink in the flow cell window of the old-style analyzer.
•
Pressurize the bottle immediately before opening the 3-way valve. Although the cap is
snug, it will not hold pressure for long periods of time.
%Dif
Avg
Y
----------
100
×
100
–
=
Reorder Information
Description
Catalog Number
CL17 Calibration/Verification Kit
54490-00
Reagent Refill Kit
28359-00
Two Bottles 500 mL ±5 mL Organic Free Water
One 20 mL Voluette
®
100-130 ppm Chlorine Standard
© Hach Company, 2002. All rights reserved. Printed in the U.S.A.
ds/dp 11/02 2ed