TM 10-6630-245-13&P
e.
Test Procedure:
WARNING
High voltage used with Spectrophotometer. Misuse can cause electrical shock and damage
equipment. When operating with 115V or 220V power, make sure the power source and
equipment are in ground potential. Ensure that the power cable connections are correct for the
desired voltage power before connecting the power source.
(1)
Refer to para 2.6.2 for set up and operation of the Spectrophotometer.
(2)
Fill each of the two spectrophotometer sample cells(7, fig. 2-5) with 25 ml of sample water. Use the
graduated cylinder(31, fig. 1-1) to collect and measure the water.
WARNING
IRON REAGENT (FERROVER® )
May cause eye and respiratory tract irritation. May cause allergic respiratory reaction if swallowed or inhaled. Harmful if
swallowed. Do not ingest or allow contact with skin or eyes. Do not breathe dust. In case of contact, immediately flush
eyes with water for 15 minutes. Remove contaminated clothing. Wash skin with soap and plenty of water. In case of
ingestion, DO NOT induce vomiting. Give one or two glasses of water. Never give anything by mouth to an unconscious
person. In case of inhalation, remove victim to fresh air. Give artificial respiration if necessary. Call medic in all cases.
(3)
Add one FerroVer® iron reagent powder pillow(22) for 25 ml samples to one of the sample cells(7, fig. 2-
5) containing the water sample. Swirl to mix.
(4)
Allow solution to stand for at least 2 minutes but not more than 10 minutes. If iron is present an orange
color will develop. Proceed to the next step while waiting.
(5)
Place the untreated cell(7) of sample water (blank sample) in to the cell holder well(5) in the
spectrophotometer. Put the "Iron (FerroVer® Method)" meter scale card(2) into the meter. Use the
wavelength dial(8) to adjust the wavelength to 510 nm. Adjust the LIGHT CONTROL knob(l0) until the
meter scale(14) reads 0 g/ml.
(6)
Remove the blank sample(7) from the spectrophotometer. Place the treated sample(7) in the cell holder
well(5). Read and record the mg/l of ferrous iron on the meter scale(14).
f.
Interpretation of Results:
NOTE
The recorded reading corresponds to the concentration of ferrous iron in the sample in mg/l.
(1)
A large excess of iron will inhibit full color development. A diluted sample should be tested if the
spectrophotometer meter reading is at the high end of the scale. Repeat the test using a test sample of
only 12.5 ml of sample water and adding 12.5 ml of deionized water to make up a total of 25 ml. Multiply
the spectrophotometer scale reading by two.
(2)
To determine the amount of ferric iron present in a sample, perform the ferrous iron test in paragraph
2.6.8.12 and subtract result from the total iron found by this test.
g.
Refer to para 2.6.2 for shut down of the Spectrophotometer.
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