LaMotte WaterLink Spin Touch FF Manuel D'instruction page 13

CONVERSIONS
Ammonia (NH )
3
Ammonia in water occurs in two forms: toxic unionized ammonia (NH
relatively non-toxic ionized form, ammonium ion (NH
both forms as ammonia (NH
actual proportion of each compound depends on temperature, salinity, and pH. A greater
concentration of unionized ammonia is present when the pH value and salinity increase.
1. Consult the table to fi nd the percentage that corresponds to the temperature, pH, and
salinity of the sample.
2. To express the test result as ppm Unionized Ammonia (NH
Ammonia test result by the percentage from the table.
3. To express the test result as ppm Ionized Ammonia (NH
Ammonia determined in step 2 from the Total Ammonia.
10°C
pH Fresh
water 1
7.0 0.19
7.1 0.23
7.2 0.29
7.3 0.37
7.4 0.47
7.5 0.59
7.6 0.74
7.7 0.92
7.8 1.16
7.9 1.46
8.0 1.83
8.1 2.29
8.2 2.86
8.3 3.58
8.4 4.46
8.5 5.55
1
Freshwater data from Trussel (1972).
2
Seawater values from Bower & Bidwell (1978). Salinity for Seawater values = 34% at an ionic strength
of 0.701 m.
) to give the total ammonia concentration in water. The
3
15°C
Salt Fresh
water 2 water
— 0.27
— 0.34
— 0.43
— 0.54
— 0.68
0.459 0.85
0.577 1.07
0.726 1.35
0.912 1.69
1.15 2.12
1.44 2.65
1.80 3.32
2.26 4.14
2.83 5.16
3.54 6.41
4.41 7.98
4 +
). This test method measures
4
20°C
Salt Fresh
water water
— 0.40
— 0.50
— 0.63
— 0.79
— 0.99
0.665 1.24
0.836 1.56
1.05 1.96
1.32 2.45
1.66 3.06
2.07 3.83
2.60 4.77
3.25 5.94
4.06 7.36
5.05 9.09
6.28 11.18
13
) and the
3
), multiply the Total
3
+
), subtract the Unionized
25°C
Salt Fresh
water water
— 0.55
— 0.70
— 0.88
— 1.10
— 1.38
0.963 1.73
1.21 2.17
1.52 2.72
1.90 3.39
2.39 4.24
2.98 5.28
3.73 6.55
4.65 8.11
5.78 10.00
7.17 12.27
8.87 14.97
Salt
water
—
—
—
—
—
1.39
1.75
2.19
2.74
3.43
4.28
5.32
6.61
8.18
10.10
12.40