PH composite electrode

pH composite electrode - Structure The pH composite electrode is mainly composed of electrode bulb, glass support rod, internal reference electrode, internal reference solution, shell, external reference electrode, external reference solution, liquid junction, electrode cap, electrode lead, socket, etc. (1)Electrode bulb: It is melt-blown from lithium glass with hydrogen function. It is spherical in shape, with a film thickness of about 0.1~0.2mm and a resistance value of <250 megaohms (25°C). (2) The glass support tube is a glass tube that supports the electrode bulb. It is made of lead glass with excellent electrical insulation. Its expansion coefficient should be consistent with the electrode bulb glass. pH composite electrode (3) internal reference electrode: It is a silver/silver chloride electrode. Its main function is to draw out the electrode potential, which requires stable potential and a small temperature coefficient. (4) Internal reference solution: The internal reference solution with zero potential of 7pH is a mixed solution of neutral phosphate and potassium chloride. The glass electrode and the reference electrode form a battery to establish the pH value of zero potential, which mainly depends on the pH value and chloride ion concentration of the internal reference solution. (5)Electrode shell: The electrode shell is a shell that supports the glass electrode and the liquid junction and holds the external reference solution. It is usually made of polycarbonate (PC) molding or glass. PC plastic will dissolve in some solvents, such as carbon tetrachloride, trichloroethylene, * * Furan, etc., if the above solvents are included in the test, the electrode shell will be damaged. In this case, a pH composite electrode with a glass shell should be used instead. (6)External reference electrode: It is a silver/silver chloride electrode. Its function is to provide and maintain a fixed reference potential. It requires stable potential, good reproducibility, and small temperature coefficient. (7)External reference solution: Potassium chloride solution or KCl gel electrolyte. (8) Liquid junction: The liquid junction is the connecting part between the external reference solution and the measured solution. It requires stable penetration and usually uses a sand core. (9)Electrode lead: It is a low-noise metal shielded wire, the inner core is connected to the internal reference electrode, and the shielding layer is connected to the external reference electrode. pH composite electrode - use (1) There should be no bubbles at the front of the bulb. If there are bubbles, they should be thrown away with force. (2) After the electrode is taken out of the soaking bottle, it should be shaken in deionized water and shaken dry. Do not wipe the bulb with paper towels. Otherwise, the electrostatic induction charge will be transferred to the glass membrane, which will prolong the potential stabilization time. A better method is to rinse the electrode with the test solution. (3) After the pH composite electrode is inserted into the solution to be measured, stir and shake it for a few times before leaving it still. This will speed up the response of the electrode. Especially when using a plastic shell pH composite electrode, the stirring and shaking should be more vigorous, because there is a small cavity between the bulb and the plastic shell. After the electrode is immersed in the solution, sometimes the gas in the cavity has no time to be discharged and bubbles will be generated, resulting in poor contact between the bulb or the liquid junction and the solution. Therefore, vigorous stirring and shaking are required to eliminate the bubbles. (4) After testing in a viscous sample, the electrode must be rinsed repeatedly with deionized water several times to remove the sample adhered to the glass film. Sometimes it is necessary to wash the sample with other solvents first, then wash away the solvent with water, and immerse it in the soaking solution for activation. (5) Avoid contact with strong acids, alkalis or corrosive solutions. If you test such solutions, you should minimize the immersion time and clean them carefully after use. (6) Avoid use in dehydrating media such as absolute ethanol and concentrated sulfuric acid, which will damage the hydrated gel layer on the surface of the bulb. (7) The shell material of the plastic pH composite electrode is polycarbonate plastic (PC). PC plastic will dissolve in some solvents, such as carbon tetrachloride, trichloroethylene, * * Furan, etc., if the above solvents are included in the test, the electrode shell will be damaged. In this case, a pH composite electrode with a glass shell should be used instead. pH composite electrode - cleaning When the bulb and liquid junction are seriously contaminated, you can first clean it with the following solvents, then wash away the solvent with deionized water, and finally immerse the electrode in the soaking solution for activation. Pollutant cleaning agent Inorganic metal oxides less than 1 mol/L Dilute acids Organic greases Dilute detergents (weakly acidic) Resins Polymer substances Dilute alcohol, acetone, ether Proteins Blood cell precipitates Acidic enzyme solutions Pigments Dilute bleach, hydrogen peroxide pH composite electrode - "repair" method The "damage" of the pH composite electrode is characterized by reduced sensitivity gradient, slow response, and poor reading repeatability. It may be caused by the following three factors. Generally, customers can use appropriate methods to repair it. (1) If the electrode bulb and liquid junction are contaminated, you can use a fine brush, cotton ball or toothpick to carefully remove the dirt. The protective cover on the head of some plastic pH electrodes can be unscrewed, making cleaning more convenient. If the pollution is serious, you can use detergent to clean it according to the previous method. (2) The external reference solution is contaminated. For rechargeable electrodes, you can prepare a new KCl solution and add it in. Be careful to pour it out when adding it for the first and second time to clean the inner cavity of the electrode. (3) Aging of glass sensitive film: Soak the electrode bulb in 0.1mol/L dilute hydrochloric acid for 24 hours. Rinse with pure water and soak in electrode soaking solution for 24 hours. If the passivation is serious, you can also soak the lower end of the electrode in 4% hydrofluoric acid solution for 3 to 5 seconds (solution preparation: Dilute 4ml hydrofluoric acid with pure water to 100m1), wash it with pure water, and then soak it in the electrode soaking solution for 24 hours to restore its performance.

Let me consult the online customer service for you. Read the content below. If you have any questions, please feel free to contact us online.: Welcome, do you need any help? I said: (2009-4-14 17:02:05) Please: What is the function of a layer of hydrated gel film on the surface of the PH composite electrode bulb? If you have any questions, please contact us online.: (2009-4-14 17:03:28) Of course it plays the role of protecting the electrode, I said: (2009-4-14 17:04:05) What kind of protection? What to prevent from harming the electrodes? If you have any questions, you can consult online.: (2009-4-14 17:04:41) Is it the protective cap mentioned? It is white and has some solution inside. If you have any questions, you can consult online.: (2009-4-14 17:05:35) That one is for protecting the electrode. You need to take it off when using it. I said: (2009-4-14 17:06:12) That’s it. Thank you.

The answer given by Floor 2 is too comprehensive, so just use his answer. Just come in and take a look. Thanks for the 2nd floor knowledge.

Purchase instructions: The E-201PH composite electrode produced by Shanghai Sanxin Instrument Factory used by our company is in large quantity. In order to ensure the quality of our company's products, it is forced to be eliminated after two uses. However, in fact, it can continue to be used, and the slope can reach 95%. This second-hand electrode is now being recycled and sold. As long as your product is not very sensitive to pH, you can use our company's recycled electrode, which will definitely meet your needs. The market price of a new electrode is about 80, but this second-hand electrode only costs 20 or 30 yuan. At present, when our store is just opening, the trial price is 10 yuan, and the price after trial is 25 yuan, excluding postage. http://www.shky1688.com/images/spacer.gif Details can be found in my Taobao store. shop57877157.taobao.com