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Note: The test will detect any calcium or magnesium contamination in the mixing cylinders,
measuring droppers or sample cells. To test cleanliness, repeat the test multiple times until
you obtain consistent results.
SAMPLE DILUTION
This meter is designed to determine low levels of hardness, typically found in water purification
systems.
When testing some other sources of water, it is not uncommon to come across levels of hardness
that are greater than the range of this meter.
This problem can be overcome through dilution. Dilutions must be performed with hardness‑free
water or the readings will be erroneus.
• Fill a 1 mL syringe with the sample.
• Place the syringe in a 50 mL beaker, making sure that the beaker is clean and empty, and
inject 0.5 mL into the beaker.
• Fill the beaker up to the 50 mL mark with hardness‑free water.
Now, follow normal measurement procedure. The true value of the sample is the reading obtained
multiplied by a factor of one hundred (the dilution factor).
For your reference, factors to convert readings in mg/L to French degrees (FD), German degrees
(DD) and English degrees (ED) of hardness are as follows:
1 mg/L = 0.1 FD = 0.056 DD = 0.07 ED
INTERFERENCES
Interference may be caused by excessive amounts of heavy metals.
• At the end of measurement, the instrument directly displays concentration in mg/L (ppm) of
magnesium hardness, as CaCO
3
, on the LCD. To convert the result to mg/L Mg, multiply the
reading by 0.243.
MEASUREMENT PROCEDURE
