Dissolved oxygen sensors are core equipment for water quality monitoring, industrial process control, and biological reaction processes. Their lifespan is affected by factors such as membrane material aging, electrode contamination, and mechanical damage. Scientific maintenance can significantly extend the service life of sensors and reduce replacement costs. Here are five key maintenance strategies:

1. Regularly replace the breathable membrane to prevent membrane failure

The breathable membrane is the core component of dissolved oxygen sensors, and its performance directly affects measurement accuracy. After long-term use, the film layer may fail due to chemical corrosion (such as strong acid and alkali environments), mechanical wear (such as water flow impact), or biological contamination (such as microbial attachment). It is recommended to replace the membrane layer every 3-6 months. If used in harsh environments such as high salinity and high suspended solids water, it should be shortened to 1-2 months. When replacing, the original matching membrane should be used to avoid measurement errors caused by differences in membrane thickness or material.

2. Clean the electrode surface to avoid the accumulation of polarizing layers

The electrode surface is prone to forming a polarizing layer due to oxidation or pollutant deposition, which hinders the diffusion of oxygen molecules and leads to slow response. Dip a soft bristled brush into deionized water and gently brush the surface of the electrode every week to remove any attachments; If the pollution is severe, soak in a 5% hydrochloric acid solution for 5-10 minutes, and then rinse with deionized water. Be careful to avoid scratching the electrode with hard objects to prevent damage to the catalytic layer.

3. Standardize the calibration process to reduce frequent operational damage

Frequent calibration can accelerate electrode aging. It is recommended to set the calibration cycle according to the usage scenario: calibration once every 2 weeks in laboratory environment and once every month in industrial field. During calibration, fresh buffer solution should be used and strictly follow the instructions to avoid electrode performance degradation caused by cross contamination of calibration solution or temperature compensation errors.

4. Control the usage environment and avoid conditions

Dissolved oxygen sensors are sensitive to temperature, pressure, and chemical environment. Long term exposure to high temperatures (>60 ℃), high pressures (>0.5MPa), or highly corrosive media can accelerate the aging of the film layer. Before use, it is necessary to confirm whether the sensor range matches the environmental conditions. For example, in seawater monitoring, salt resistant sensors should be selected to avoid membrane rupture caused by chloride ion erosion.

5. Regularly activate electrodes to restore catalytic activity

After long-term disuse, the electrode catalytic layer may respond slower due to deactivation. Before discontinuation, rinse with deionized water and store in a dry environment after drying; Before reactivation, soaking the electrode in a 0.1mol/L sodium hydroxide solution for 24 hours or applying a polarization voltage of 0.8V for 1 hour can effectively restore catalytic activity and extend its service life.