TM 10-6630-245-13&P
(5)
Wait at least 5 minutes for full color development in the treated sample. Do not wait more than 15 minutes
before completing steps (6) and (7) below.
(6)
Place the "Nitrogen, Nitrate (NitraVer® 5 Method)" meter scale card(2, fig. 2-5) into the meter. Adjust the
wavelength dial(8) to 500 nm. Place the untreated (blank) sample of water in the Spectrophotometer cell
well(5). Adjust the LIGHT CONTROL knob(l0) for a meter scale(14) reading of 0.0 g/ml.
(7)
Remove the blank sample from the Spectrophotometer. Place the treated sample into the cell well(5).
Read the mg/l of nitrate nitrogen on the meter scale(14). Record results.
f.
Interpretation of Results:
NOTE
The meter reading is in mg/l of nitrogen (N) present as nitrates in the sample.
To express results as mg/l of nitrates (NO3), multiply the meter reading by 4.4.
g.
Refer to para 2.6.2 for shut down of the Spectrophotometer.
2.6.8.16. pH Wide Range Test.
a.
Purpose of Test: To determine the acidity or alkalinity of a water sample expressed as the total pH of the sample.
b.
Range: pH 4 to 10
c.
Equipment Used: Found in Main Carrying Case, para 1.8, fig. 1-1
Volumetric pipet, 1.0 ml, (5), fig. 1-1
pH indicator solution, (14), fig. 1-1
Spectrophotometer, (20), fig. 1-1
Pipet filler, (27), fig. 1-1
Graduated cylinder, (31), fig. 1-1
d.
General Techniques Used: Refer to paragraphs cited below as required by procedure.
Planning the Test, para 2.6.1.1
Cleaning Glassware, para 2.6.1.2
Handling and Storing Reagents, para 2.6.1.3
Collecting Water Samples, para 2.6.1.4
Mixing, para 2.6.1.5
Using Graduated Cylinders, para 2.6.1.6
Using Pipets, para 2.6.1.7
Spectrophotometer, para 2.6.2.2
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.
(3)
Place one cell(7, fig. 2-5) (used as a "blank") in the spectrophotometer cell holder well(5). Insert the
"Wide Range pH" meter scale card(2) into the meter. Adjust the wavelength dial(8) to 520 nm. Turn the
LIGHT CONTROL knob(l0) until the meter scale(14) needle rests at the far right of its travel arc.
2-51
