Calibration method and device for dissolved oxygen sensor

Abstract

The invention discloses a calibration method and a calibration device for a dissolved oxygen sensor, which are high in calibration precision, simple in structure and convenient to operate. Combined gas (N2 and O2 mixed gas) calibration replaces solution calibration, so that the influence of instability of the oxygen concentration in a solution on a measurement error is avoided; due to combined gas which is prepared according to a designed proportion, different oxygen concentrations with high precision can be obtained, so that the proportioning process of different oxygen concentrations in the solution is simplified, the precision of the oxygen concentration is improved, and the calibration time is shortened; the combined gas is a mixed gas of N2 and O2 and cannot pollute the atmosphere after being dispersed into air; meanwhile, no chemical reagent is needed in the calibration process, so that harm to a human body and secondary pollution to liquid to be detected are avoided; the whole dissolved oxygen sensor device only needs one closed container and several prepared mixed gases with different concentrations, so that a standard device is simple, is convenient to operate and has a good application prospect.

Description

technical field [0001] The invention relates to the field of measurement technology, in particular to a calibration method and device for a dissolved oxygen sensor. Background technique [0002] Traditional dissolved oxygen sensors 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 ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem solved by the present invention is to overcome the calibration method of the dissolved oxygen sensor in the prior art, which has low precision, complex structure, cumbersome operation, and the oxygen concentration in the aqueous solution should not be stable.

Images