Online TP/PO4-P Total Phosphorus/Phosphate Analyzer

Online TP/PO4-P Total Phosphorus/Phosphate Analyzer

Principle: Molybdenum blue method+spectrophotometric method

Under heating and ultraviolet irradiation conditions, the atomic oxygen generated by the decomposition of persulfate converts the phosphorus element in phosphorus containing compounds into orthophosphate (this step is not required for measuring orthophosphate); Under acidic medium and antimony salt conditions, the phosphomolybdic acid formed by the reaction of orthophosphate and ammonium molybdate is reduced to a blue complex by ascorbic acid. Its absorbance is measured at a wavelength of 700 nm and converted to the corresponding concentration value.

On the basis of the national standard method, UV digestion has been added to improve the efficiency of total phosphorus digestion, resulting in a higher phosphorus recovery rate (over 98% for pyrophosphate and over 95% for organic phosphorus), and more accurate actual water sample testing.

The "digestion colorimetric module" adopts an integrated design with independent patented technology, which avoids additional measurement errors introduced by sample circulation after digestion, effectively reduces cleaning waste liquid, and shortens the measurement cycle.

The UV lamp used for UV digestion is placed on the periphery of the digestion cup instead of inside, thus reducing the requirements for the applicability of the UV lamp, extending its service life, and facilitating future maintenance or replacement.

Adopting the independently patented "automatic injection and dose measurement" technology, coupled with optimized reagent formulations and other proprietary technologies, the sensitivity and measurement stability of the instrument have been significantly improved.

Using proprietary technology, the "background absorption and turbidity correction" function has been achieved, greatly reducing the impact of water sample blackening, discoloration, or turbidity on measurement. (This function is only applicable to orthophosphate)

Application

The field of online monitoring of water quality in fixed pollution sources such as industrial wastewater, domestic sewage, and wastewater discharge, as well as surface water, groundwater, drinking water sources, nearshore waters, and nearshore waters.

Specifications

Measurement range: 0-500ppb; 0-1 mg/L； Other ranges can be customized.

■ Indication error Note 1: ± 1.5% F.S. Note 2

Repetitive Note 3: ≤ 1.0%

■ Zero drift note 4: ± 0.2% F.S

■ Range drift note 5: ± 1.5% F.S

■ Quantitative lower limit note 6: ≤ 2.5 ppb (the upper limit requirement for Class I surface water is 20 ppb) ■ Actual water sample comparison test: ± 2.5%

Note 1: When selecting a range of 0-1 mg/L, the instrument continuously measures a standard solution with a concentration of 0.5 mg/L under the same conditions for 6 times. The percentage difference between the average of the 6 parallel measurements and the nominal concentration value relative to the range value is the indication error.

Note 2: F S. It refers to the range of 0-1 mg/L.

Note 3: Select the range of 0-1 mg/L, measure the zero point calibration solution 6 times, and take the average of 6 times as the zero point value; Afterwards, the range calibration solution with a concentration value of 0.8 mg/L was measured 6 times, and the relative standard deviation of the 6 measured values after zero point calibration is the repeatability.

Note 4: Select the range of 0-1 mg/L and measure the zero calibration solution continuously 24 times with a cycle of 1 hour; Take the average of the first 3 measurements as the reference value, calculate the percentage of absolute deviation between the subsequent 21 measurements and the reference value relative to the range value, and take the maximum as the zero drift.

Note 5: Select the range of 0-1 mg/L and test the range calibration solution with a concentration of 0.8 mg/L three times before and after the zero drift test. Calculate the average value of the two groups before and after the test; The percentage of the absolute deviation of the average value of the rear group after deducting zero drift from the average value of the front group relative to the range value is called range drift.

Note 6: Select a range of 0-500 ppb, and the instrument continuously measures a standard solution with a concentration of 25 ppb under the same conditions for 7 times. Calculate the standard deviation of the 7 parallel measurements, and 10 times the obtained standard deviation is the lower limit of quantification of the instrument.