13. Why PH meter buffer structure within the validity period, has gone can not be used? Validity refers to the buffer shelf unopened use state. Once opened use, due to the various roles of mold in the air easier deterioration. Recommendation: buffer after opening, refrigerate 14. Why save the measurement time up to 3 minutes or longer reasons: (1) the sample is ion-deficient (2) electrode aging improvements: (1) use Inlab420 / LE420 electrode (2) activation or replaced with new electrode 15. 3M KCl / AgCl solution with 3M KCl solution, what is the difference 3M KCl / AgCl KCl solution is saturated with AgCl. Since the reference electrode pH electrode consists of Ag / AgCl, there is a balance in the solution as follows: AgCl Ag ++ Cl- increased Cl- solution and Ag +, you can shift the equilibrium to the left, to prevent the dissolution of AgCl, thus protecting the reference the working electrode. When the sample measurement contained S2-, Council and the Ag + reacts Ag2S precipitation, leaving the junction is blocked, so when measured solution containing S2-, to use free of AgCl KCl solution. PH meter principle of knowledge - pH meter Compendium - Changzhou hundred Cheng Technology Co., Ltd. All PH meter acidity _ _ _ dissolved oxygen meter conductivity meter factory direct price after the above approach to the electrodes must be washed with pure water, then soaked in 3.3 MKCL electrode soaking solution for 12 hours. Self-cleaning: When jet, PH meter need to be able to control output remains at a constant value before cleaning PH meter, that after this time locking the meter output during the cleaning instrument output remains unchanged until the cleaning is completed solution PH value is stable, PH meter further detection output. Fifth, how to deal with the aging of the electrodes, the electrodes to choose the right type, easy to use. 1) how to deal with the aging of the electrode: PH meter glass electrode layer structure with progressive aging changes. Old electrode response is slow, film resistors PH meter high principle, the slope of the low. Etching away the outer layer with hydrofluoric acid PH meter maintenance methods can often improve electrode performance. If this method to periodically clear the inner and outer layer, the electrode life is almost unlimited. Solution: electrode activation - the aging electrodes may be immersed in a mixed solution of 1M acetic acid and 1M potassium chloride (1: 1), activation 10min after removing clean. Aging without serious electrodes can be soaked in distilled water or 0.1N dilute hydrochloric acid solution activated 24h. Changzhou PH meter manufacturers | Baicheng Technology (certified) | PH meter provided by Changzhou Best Technology Limited. Changzhou one hundred Technology Limited (www.czbckj.com) Jiangsu Changzhou, chemical instrumentation leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In one hundred as a technological leader with the staff warmly welcome all inquiries negotiations to create one hundred to a better future technology.