Dissolved Oxygen Sensor FAQ【SEN0237】

Q1:How to configure the saturated dissolved oxygen water by myself ? 

A1:You can pump air into water for about 20 minutes to saturate the water with oxygen to obtain 100% dissolved oxygen standard liquid.  

Q2:How to make zero dissolved oxygen water ? 

A2:Add sodium sulfite(Na2SO3) into water until it is saturated. This can consume all the oxygen in the water to obtain the zero dissolved oxygen liquid.  

Q3:How to store the probe ? 

A3: 

1. Short time (over night to a week ): dip the probe into purified water or deionized water to prevent the filling solution from evaporating. Disconnect the probe from the main instrument every time when it is not in use. 

2. Long time: (over a week): unscrew the cap from the probe and wash the electrodes core (cathode: platinum, anode: lead) and wash the cap with purified water or deionized water. Dry all the components with tissue. Screw the cap back to the probe without adding any filling solution to prevent the anode from being consumed. Put all the components back into the package.  

Q4:How to make 0.5 mol/L NaOH solution? 

A4:You need to purchase the NaOH solution first, and add 1~2 drops glycerinum to the NaOH solution for every 100mL. Only by adding the NaOH solution into the probe can it be ready for use.  

Q5:What problems would I usually meet ? How to solve it ? 

A5： 

1. If the readings of zero dissolved oxygen liquid is not zero or close to zero, you can polish the cathode of the probe. 

2. If the readings is not within normal range or the readings drifts, please check the membrane on the cap. If there are cracks, holes or contaminations on the membrane, please change the cap.  

Q6:How to deal with probe electrode corrosion? 

A6:You can try to use a brush to clean the rust on it and replace the electrolyte inside. The service life of the electrode is about 1 year. After the service life is exceeded, the entire electrode probe needs to be replaced, which cannot be repaired.

If you have other questions, just feel free to post them in our forum for consultation. We will reply them as soon as possible and improve the product FAQ gradually.