Hydrion 10 - Standard Calibration Fluid

17
2.3.5 Standard Calibration Fluid
Shown below is the recipe for making a standard calibration fluid for surface water and the like. This calibration fluid is
especially useful for the measurement of drinking water in most areas.
General Remarks
• The EC is adjusted to 20 °C.
• NH
4
+
and NO
3
-
are expressed as total weight, not as pure -N.
• HCl must be added last to the volumetric flask, which is first filled with demineralized water (+ 4000 ml for the big
flask). CO
2
starts to develop as soon as HCl is added. This is why the bottles with calibration fluid must be tightly
sealed with as little air inside as possible.
Recipe for Standard Calibration fluid 2 (B) and 3 (C)
Stock solution Pipette
fluid 2
(B)
fluid 3 (C)
NH
4
Cl
Ca(NO
3
)
2
KHCO
3
CaCl
2
NaHCO
3
HCl
0,01 M
0,05 M
0,025 M
0,15 M
0,3125 M
0,1 M
20 ml per 5000 ml
20 ml “
20 ml "
20 ml "
20 ml "
20 ml "
100 ml per 5000 ml
100 ml “
100 ml "
100 ml "
100 ml "
100 ml "
Calibration fluid 2 and Calibration fluid 1 are respectively 5x and 25x diluted solutions of Calibration fluid 3.
It is best to make Calibration fluid 2 directly and not as a dilution of Calibration fluid 3.
Recipe for Standard calibration fluid
1
Fluid 1 (A)
5000 ml graduated flask
¾ filled with demi-water
Fluid 3
(C)
200 ml (pipette)
Composition Calibration fluids
fluid 1 (A)
Fluid 2 (B)
fluid 3 (C)
PPM
µ
mol
/
li
ter
PPM
µ
mol
/
liter
PPM
µ
mol
/
liter
[K
+
]
[Na
+
]
[Ca
2+
]
[NH
4
+
]
[Cl
-
]
[NO
3
-
]
[HCO
3
]
0.782
5.75
6.42
0.144
11.644
4.96
11.59
20
250
160
8
328
80
190
3.9
28.75
32.1
0.7
58.22
24.8
57.95
100
1250
800
40
1640
400
950
19.55
143.75
160.4
3.6
291.1
124.0
289.75
500
6250
4000
200
8200
2000
4750
EC
20
±64 microS/cm EC
20
±309 microS/cm EC
20
± 1450 microS/cm
pH ± 6.7 pH ± 6.7 pH ± 6.7