●pH Electrode has to be adjusted by adjustor liquid before using.
●The sphere at the end of pH electrode is prohibited from touching, wiping, getting in touch with oil sludge.
●pH electrode need to be well kept in adjustor liquid when not using. 
●In order to extend the lifespan of electrode, it needs to be used under correct instruction. 
●Noted that the water line should be under the plastic cover of wire. 
●pH electrode is only applied to measuring pH value of fresh and marine water.