Seek PH solution for analytical instruments
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Dear teachers, there are 7 pH meters on site to measure the pH of the wastewater. The wastewater contains a small amount of organic substances and NaOH; its pH ranges from 8 to 13, and the temperature is between 50 and 65°C. The brand of these pH meters is Foxboro. After about 4 months of use, inaccurate measurements occur; calibration sometimes helps and sometimes doesn’t. The PH electrodes purchased cost around 7000 – I’m looking for ways to reduce costs.
This post was last edited by tiger2010 on 2023-1-3 at 10:14. Are there any installed photos? Digital electrodes or analog electrodes? What are the processes involved in treating wastewater? Which parts are prone to failure, and what are the specific symptoms?
It is recommended to activate the electrodes, purchase spare electrodes, and alternate between them.
Is the electrode made of glass or a composite material, and where is the damage? I’m currently using the CPS11D glass electrode from E+H. It used to break down frequently; later it was found that the issue was caused by particle impacts resulting from changes in the measurement medium’s processing parameters. After adjusting the process, such breakdowns have become rare and the measurements are now very accurate. The measuring medium is alkaline wastewater 8-11, with a pressure of 0.4 MPa and a temperature of 75°C℃
As a supplementary note, the price of electrodes of this model is around 3,000, offering a decent cost-performance ratio
A way to reduce the cost of glass electrodes is to clean and activate the electrodes oneself. In the past, the instructions for domestically produced glass electrodes always included maintenance methods. Find a domestic manufacturer of electrodes to consult with, and purchase their cleaning and activation agents.
Flat electrodes can be chosen; they were recently used in a desulfurization process at a chemical plant. Due to severe erosion and high pressure, electrodes resistant to high pressures were selected. At present, they need to be replaced every 8 months, and the cost of each electrode is over 2,000. The customers are quite satisfied with them. Other electrodes purchased before either broke after just one afternoon of use or failed within a week.
Firstly, the glass electrode of a pH meter is a consumable item. When selecting and configuring a pH meter for monitoring the pH of sewage and wastewater, it is necessary to take into account the effects of the medium and the application environment. Additionally, proper maintenance of the electrode is also a fundamental requirement to ensure the reliability of measurements and the normal lifespan of the device. Regarding the wastewater from petroleum and chemical enterprises, its composition can be complex, and even trace amounts of certain components may have an impact on electrodes. There are many types of pH electrodes available, and if the purchaser issues a tender based on low prices without conducting thorough technical discussions and selecting the appropriate models for each application site beforehand, it is normal for problems to arise during use.
1. The brand doesn’t matter as long as it is produced by a legitimate manufacturer; the cost should be within 2,000. 2. Determine the location for embedded installation, check whether the flow rate is stable, and ensure that there is no excessive erosion. 3. The manufacturer should recommend an appropriate electrode material based on the operating conditions. 4. Regular cleaning, maintenance, and calibration are required. Apart from circuit installation, these are the main aspects to consider. Please, expert, add more details.
I have encountered similar problems; I was using an Emerson pH meter. It is recommended to reduce the temperature of the medium to below 25°C, and a tubular heat exchanger can be used for cooling. There are many ways to achieve cooling, and the appropriate method can be chosen based on the actual situation. The goal is to lower the temperature of the medium in order to extend the lifespan of the electrodes