The HI96700 Portable Photometer provides a simple, accurate and cost effective way to measure ammonia. Present naturally in surface and wastewaters, ammonia is largely present from deamination of organic nitrogen-containing compounds and hydrolysis of urea. Ammonia may also be present from water treatment processes that utilize chloramaines for disinfection, where ammonia is added to the water to react with chlorine. Ammonia is less likely to appear in groundwater due to adsorption to soil particles.
The HI96700 uses an adaptation of the ASTM Manual of Water and Environmental Technology, D1426-92 Nessler method to measure ammonia concentrations of less than 3.00 mg/L (ppm) ammonia-nitrogen. When the Nessler reagent is added to samples containing ammonia, the sample will turn a yellow hue; the greater the concentration, the deeper the color. The associated color change is then colorimetrically analyzed according to the Beer-Lambert Law. This principle states that light is absorbed by a complimentary color, and the emitted radiation is dependent upon concentration. For low levels of ammonia, a narrow band interference filter at 420 nm (violet) allows only violet light to be detected by the silicon photodetector and omits all other visible light emitted from the tungsten lamp. As the change in color of the reacted sample increases, absorbance of the specific wavelength of light also increases, while transmittance decreases.
The HI96700 utilizes the above principle to measure concentration; in just a few simple steps, results are obtained in an accurate and efficient manner.
Range 0.00 to 3.00 mg/L (ppm) (as ammonia-nitrogen) Resolution 0.01 mg/L (ppm) Accuracy @ 25°C (77°F) ±0.04 mg/L ±4% of reading Light Source tungsten lamp Light Detector silicon photocell with narrow band interference filter @ 420 nm Method adaptation of the ASTM Manual of Water and Environmental Technology, D1426-93, Nessler method Auto-off after ten minutes of non-use in measurement mode; after one hour of non-use in calibration mode; with last reading reminder Environment 0 to 50°C (32 to 122°F); RH max 95% non-condensing Battery Type 9V battery Dimensions 193 x 104 x 69 mm (7.6 x 4.1 x 2.7”) Weight 360g (12.7oz.) Ordering Information HI96700 is supplied with sample cuvettes (2) with caps, 9V battery, instrument quality certificate and instruction manual.