-
E-mail
122092220@qq.com
-
Phone
15800931558
-
Address
Room 202, Building 3, No. 38 Jianyun Road, Zhoupu Town, Pudong New Area, Shanghai
Shanghai Sanben Environmental Protection Technology Co., Ltd
How to distinguish the quality of industrial dissolved oxygen analyzer?
Date: 2016-05-19Read: 0
Industrial dissolved oxygen analyzerIt is a device for measuring dissolved oxygen in water. Its working principle is that oxygen is reduced by the working electrode through the diaphragm, generating a diffusion current proportional to the oxygen concentration. By measuring this current, the concentration of dissolved oxygen in water can be obtained. According to different concentrations, diaphragm electrodes are divided into two types: polarographic and electrochemical. The polarographic diaphragm electrode uses silver silver chloride as the counter electrode, potassium chloride as the electrolyte inside the electrode, and polyethylene and polytetrafluoroethylene films with a thickness of 25-50 μ m on the outside of the electrode. The film blocks the liquid exchange between the inside and outside of the electrode, allowing dissolved oxygen in the water to penetrate into the inside of the electrode. The voltage between the two electrodes is controlled at 0.5-0.8V, and the concentration of dissolved oxygen can be determined by measuring the diffusion current through an external circuit. The primary battery uses silver as the anode electrode and lead as the cathode electrode. The anode electrode and silver electrode are immersed in a potassium hydroxide electrolytic cell to form two half cells, with the outer layer also sealed with a thin film. Dissolved oxygen is reduced at the anode, generating a diffusion current. The concentration of dissolved oxygen can be determined by measuring the diffusion current.
1、 Check the measurement display unit
1. Set the power switch of a single measuring unit without an oxygen electrode to either "zero" or "measurement" mode, and then set the measurement selection function switch to "temperature" mode.
The displayed value should be around 28.0;
2. Turn the measurement selection switch to the "dissolved oxygen" position, set the power switch to the "measurement" position, and adjust the "zero adjustment" potentiometer or "calibration" potentiometer separately to display the reading
There should be changes.
If the above measurements are normal, it can be judged that the measurement display unit is preliminarily qualified. Otherwise, there may be a problem with the instrument.
IIIndustrial dissolved oxygen analyzerApplication judgment of measuring room temperature in the "temperature" range
Insert the oxygen electrode plug into the socket of the instrument, turn the measurement selection switch to the "temperature" position, and the room temperature value should be displayed correctly at this time.
If there is a significant deviation in the actual measurement value, it is necessary to use a multimeter in the ohm range to test the oxygen electrode:
The resistance between pins 1 and 2, and the resistance between pins 13 and 5 should both have tens of K Ω (50K Ω at 25 ℃).
If there is a significant difference in resistance, it is necessary to check whether the electrode connection joint is firm or replace the oxygen electrode to solve the problem.
If the resistance check is normal, the instrument needs to be sent for repair.
IIIIndustrial dissolved oxygen analyzerJudgment and processing of oxygen electrode calibration in the "dissolved oxygen" mode
After the temperature measurement check is normal, turn the measurement selection switch to the "dissolved oxygen" position.
Put the oxygen electrode filled with electrolyte into 5% fresh self-made sodium sulfite for "zero adjustment" potentiometer;
Put the cleaning electrode into the air, and adjust the "calibration" potentiometer to calibrate the corresponding oxygen value of the air temperature.
If the reading is too low or too high to reach the required value, the battery, electrolyte, film, and treatment of the gold cathode and silver anode can be solved according to the product manual. If the requirements are still not met, the electrode needs to be replaced.
Note: If there are missing strokes on the instrument display, it is often caused by the loosening of the LCD display block pins during transportation. Solution: You can open the front and back covers, find the LCD display block and re plug it tightly to easily solve the problem