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Hca1 micro cl (dpd-1, -4) strip interferences, Hca1 chlorine plus tips for best accuracy – Electro-Chemical Devices (ECD) HCA1 User Manual

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HCA1 Micro CL (DPD-1, -4) Strip Interferences

Interfering Substance

Interference Level and treatment

Acidity

If sample has acidity above 150mg/L CaCO

3

test may not develop full color. Neutralize to

pH 6.0 to 7.0 with 0.5N sodium hydroxide.

Alkalinity

If sample has alkalinity above 200mg/L CaCO3

test may not develop full color. Neutralize to

pH 6.0 to 7.0 with 0.5N sulfuric acid.

Bromine & Bromamines, Br2

Color similar to free chlorine reaction at all

levels.

Chlorine Dioxide, ClO2

Color similar to free chlorine reaction at all

levels.

Copper, Cu+2

Color development is reduced above 10 ppm

(mg/L).

Iodine, I2

Color similar to free chlorine reaction at all

levels.

Manganese, oxidized (Mn+4, Mn+7)

or Chromium, oxidized (Cr+6)

See AWWA procedure 4500-CL F, 1(d) for

removal of interferences.

Monochloramine (NH2Cl)

(applies to DPD-1 only)

Monochloramine interferences are known to

occur in free chlorine

DPD methods. This interference is dependent

on temperature and

Monochloramine concentration.

Ozone, O3

Color similar to free chlorine reaction at all

levels.

Peroxides

Interference is possible.

pH

Typical pH samples of potable water with a

pH of 6.0 to 9.0 are OK. If outside this range

adjust to pH 6.0 to 7.0 using acid (0.5N

Sulfuric acid) or base (0.5N Sodium

hydroxide).


HCA1 Chlorine Plus Tips for Best Accuracy

1. Become familiar with the meter and the different tests by reading the

instructions carefully.

2. The Free Chlorine and Total Chlorine reagents are compliant for meeting

USEPA (4500-Cl G); ISO 7393/2; and German DIN 38408 G4-2 requirements.

3. Observe the dip time (as required for the test) for accurate results.

4. Test immediately after filling the CELL when testing for oxidizers.

5. Be sure the CELL is filled to capacity (4ml).

6. Rinse the CELL with clean water immediately after completing the test. (DPD

will stain the

CELL wall if allowed to remain in the CELL)

7. Just before testing, rinse the sample CELL with the sample water several times

to get a representative sample. Store the meter and all test materials out of

direct sunlight and away from chemical storage areas.

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