The continuous determination of ammonium in the OA 110 module is carried out according to the potentiometric measuring principle with a gas-sensitive NH3 electrode. Sodium hydroxide is added to the thermostatted sample to convert the ammonium dissolved in the medium into undissociated ammonia gas. The gaseous ammonia alters the pH registered by the measuring electrode; the alteration is a direct measure of the ammonium concentration in the sample.
| Standard 1 | ||
| Measuring Ranges | NH4-N: | 0.1 ... 1000 mg/l; 0.01 ... 71.00 mmol/l |
| NH4+: | 0.1 ... 1280 mg/l; 0.01 ... 71.00 mmol/l |
|
| Resolution (Display) |
Range: | 0.10 ... 10 mg/l: 0.01 mg/l 10.0 ... 100 mg/l: 0.1 mg/l 100 ... 1000/1280 mg/l: 1 mg/l |
| Standard 2* | ||
| Measuring Ranges | NH4-N: | 0.05 ... 10 mg/l; 0.005 ... 0.71 mmol/l* |
| NH4+: | 0.05 ... 12.8 mg/l; 0.005 ... 0.71 mmol/l* |
|
| Resolution (Display) |
Range: | 0,05 ... 10 mg/l: 0,01 mg/l* |
| * around calibration standard |
The ability of nitrate ions to absorb UV light of certain wavelengths is used for measuring the nitrate. The ultraviolet light from a pulsed photoflash lamp passes through a flow-thru measuring cuvette where it is partially absorbed by the nitrate ions present in the sample flow. The intensity of the attenuated light is measured at a measuring wavelength and at a reference wavelength and evaluated electronically. The 4-beam measuring method used ensures a high degree of longterm stability and absolute accuracy; interfering background influences are efficiently compensated.
Absorption measurement of aqueous sample in UV range. The SAC (spectral absorption coefficient), measured with a wavelength of 254 nm, represents the organic water pollution.
| Measuring Range | NO3-N: | 0.1 - 60 mg/l |
0 - 4000 mmol/l | |
| NO3: | 0.1 - 250 mg/l |
0 - 4000 mmol/l | ||
| SAK: | 0.1 - 200m-1 | |||
| Resolution (Display) | Nitrate: | Range: | 0.1 ... 100 mg/l : 100 ... 250 mg/l : |
0.1 mg/l 1 mg/l |
| SAK: | 0.1 m-1 (only OS 210) |
The measuring principle of the NO2 analyzer module is based on the azo dye method. A reagent reacts with nitrite to color the sample solution pink. The intensity of the pink color is proportional to the nitrite concentration in the sample and is measured by a double-beam reference photometer. An additional manual correction facility allows the system to be adapted to plant-specific characteristics so that a high degree of measuring accuracy can be achieved even with strongly colored samples.
| Measuring Range | NO2-N: | 0.005 - 1.200 mg/l | 0.40 - 90 µmol/l |
| NO2-: | 0.020 - 4.000 mg/l | 0.40 - 90 µmol/l | |
| Resolution (Display) | Range: | 0.005 ... 1.200 mg/l : 0.40 ... 90.00 µmol/l : |
0.001 mg/l 0.1 µmol/l |
