Analytical technique – LaMotte AT Visual Series Water Softener Demo Kit User Manual
Page 5

5
ANALYTICAL TECHNIQUE
1. Clean glassware is a must for accurate results. Thoroughly rinse
test tubes before and after each test. Caps and stoppers should
also be cleaned after each use.
2. Use test tube caps or stoppers, not your fi ngers, to cover test
tubes and fl asks during shaking or mixing.
3. When adding sample to calibrated test tube, be sure vial is fi lled
to the appropriate mark. The bottom of the liquid (meniscus)
should be level with the desired mark. (Figure 1)
4. When dispensing reagents from bottles fi lled with dropper plug
and cap, be sure to hold bottle vertically and gently squeeze to
dispense the appropriate number of uniform drops. (Figure 2)
5. For those reagents to be added with the screwcap pipet assemblies
enclosed, remove polyseal cap on bottle and replace with the
screwcap pipet.
NOTE: Place the polyseal caps back on the reagent bottles for
longer periods of storage. Be sure that both pipet assemblies
and polyseal caps are thoroughly cleaned before placing on
bottles to avoid contamination.
6. When dispensing reagents from pipets, hold pipet vertically
to assure uniform drop size. This is extremely important when
performing drop count titrations. (Figure 3)
7. To
fi ll pipets, squeeze rubber bulb and immerse into reagent.
Release bulb to fi ll. (Figure 4)
8. To accurately dispense powdered reagents with spoon, tap
spoon on edge of reagent container to remove excess reagent.
(Figure 5)
9. When performing tests that include Octa-Slide 2 Comparators,
the comparator should be positioned between the operator and
non-direct sunlight. This allows the light to enter through the
light-diffusing screen at the back of the comparator for optimum
color comparison.