Lamotte com pany – LaMotte CALCIUM HARDNESS FOR FRESH OR SALT WATER CA-DR User Manual
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5.
While gently swirling the tube, slowly depress the plunger to titrate the
sample until the red color changes to purple then to blue. Read the test
result directly from the scale where the large ring on the
Titrator meets
the Titrator barrel. Record as ppm Calcium Hardness as CaCO
3
.
NOTE:
Disregard any color change back to purple after five seconds.
EXAMPLE:
Large ring is 3 minor divisions below line 80. Test result is
80 plus (3 divisions x 4) equals 92 ppm.
6.
If the plunger reaches the bottom line on the Titrator scale (200 ppm)
before the endpoint color change occurs, refill Titrator and continue the
titration. When recording the test result, be sure to include the value of
the original amount of reagent dispensed (200 ppm).
ANAL Y SIS OF HARD NESS IN SALT WA TER
When sea and estuarine waters containing very high levels of mineral salts are
to be tested, the sample must be diluted before titration.
CALCIUM HARDNESS DILUTION (1 TO 12.9)
1.
Use the 0.5 mL pipet (0353) to transfer 1.0 mL (two measures) of the salt
water sample to the test tube (0608).
2.
Dilute to 12.9 mL line with distilled water.
3.
Add 6 drops of *Sodium Hydroxide Reagent w/Metal Inhibitors (4259).
Cap and mix.
4.
Add one Calcium Hardness Indicator Tablet (T-5250). Cap and gently
mix until tablet disintegrates. Solution will turn red.
5.
Fill the Direct Reading Titrator (0382) with Hardness Reagent #7
(4487DR). Insert into the center hole of the test tube cap.
6.
While gently swirling the tube, slowly depress the plunger to titrate the
sample until the red color changes to purple then to blue. Read the test
result directly from the scale where the large ring on the Titrator meets
the Titrator barrel. Multiply by 5.16. Record as ppm Calcium as Ca
++
.
NOTE:
Disregard any color change back to purple after five seconds.
EXAMPLE:
Large ring is 3 minor divisions below line 80. Titrator
reading is 80 plus (3 divisions x 4) equals 92. Multiply by 5.16. Test result
is 474.72.
7.
If the plunger reaches the bottom line on the Titrator scale (200 ppm)
before the endpoint color change occurs, refill the Titrator and continue
the titration. When recording the test result, be sure to include the value
of the original amount of reagent dispensed (200 ppm).
LaMOTTE COM PANY
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