Dissolved oxygen sensor calibration device and dissolved oxygen sensor calibration method

Abstract

The invention discloses a dissolved oxygen sensor calibration device and a dissolved oxygen sensor calibration method. The dissolved oxygen sensor calibration device comprises a calibration chamber, agas mixing pipeline communicated with the calibration chamber, and an oxygen input interface, a nitrogen input interface and a saturated steam input interface which are connected with the gas mixingpipeline, and the calibration chamber is provided with a liquid seal port communicated with the inner cavity of the calibration chamber and at least two sensor mounting ports. According to the dissolved oxygen sensor calibration method, oxygen, nitrogen and saturated steam are matched with a dissolved oxygen sensor calibration device for calibration. The dissolved oxygen sensor calibration deviceand the dissolved oxygen sensor calibration method are high in calibration precision of the dissolved oxygen sensor, free of chemical pollution, easy to operate and high in safety of the calibration process.

Description

technical field [0001] The invention relates to the field of measurement technology, in particular to a dissolved oxygen sensor calibration device and a dissolved oxygen sensor calibration method. Background technique [0002] Traditional dissolved oxygen sensor calibration methods generally use two-point calibration, that is, zero-point calibration and full-scale calibration. The calibration solution and calibration method are as follows: the excess Na 2 SO 3 Dissolved in distilled water and stirred thoroughly to make Na 2 SO 3 Absorb all the oxygen in the solution to obtain an anaerobic aqueous solution, and measure the zero point error of the instrument; at (25±0.5) °C, pass air into distilled water to saturate the dissolved oxygen concentration, and then let it stand for a while Make the dissolved oxygen stable, and then measure the range error of the instrument. When measuring the range, the solution needs to be stirred continuously to prevent the dissolved oxygen in...

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Problems solved by technology

[0002] Traditional dissolved oxygen sensor calibration methods generally use two-point calibration, that is, zero-point calibration and full-scale calibration. The calibration solution and calibration method are as follows: the excess Na 2 SO 3 Dissolved in distilled water and stirred thoroughly to make Na 2 SO 3 Absorb all the oxygen in the solution to obtain an anaerobic aqueous solution, and measure the zero point error of the instrument; at (25±0.5) °C, pass air into distilled water to saturate the dissolved oxygen concentration, and then let it stand for a while Make the dissolved oxygen stable, and then measure the range error of the instrument. When measuring the range, the solution needs to be stirred continuously to prevent the dissolved oxygen in the solution from being consumed at the moment of contact with the membrane, which will affect the measurement accuracy. The entire measurement process takes a long time , and the zero point calibration requires the chemical reagent Na 2 SO 3 , has irritating effects on eyes, skin and mucous membranes, and the calibration produces waste liquid, which is easy to pollute the environment. During full-scale calibration, in order to achieve oxygen saturation and stable concentration, it must be aerated for a long enough time and need to stand for a certain period of time. Time, so the calibration takes a long time and the calibration efficiency is low. The most important thing is that this calibration method cannot verify the accuracy of other points within the range of the measuring instrument;

[0003] In addition, another test method has been reported in some literatures, and the saturated N 2 solution and saturated O 2 Solution, by adjusting the flow rate of the peristaltic pump, and then mixing them in different proportions, the concentration of oxygen in different solutions can be obtained, so as to achieve the purpose of testing the performance of the dissolved oxygen sensor. Two saturated N 2 solution and saturated O 2 The configuration time of the solution is long, the stability is poor, and affected by the accuracy of the peristaltic pump, the dissolved oxygen concentration is difficult to meet the accuracy requirements of the instrument

[0004] Moreover, the above two calibration methods are complicated enough, and the operation is cumbersome, and the oxygen concentration in the aqueous solution should not be stable.

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