A brief understanding of the use of high temperature PH tester
The high temperature resistant PH tester is a commonly used measuring instrument and has certain applications in many industries. Users need to know all kinds of knowledge when using the high temperature resistant PH meter, such as the composition, principle, installation, maintenance and other knowledge of the online PH meter. A pH meter is very important. Today, the editor will introduce to you the knowledge of using the high temperature PH tester in detail, and I hope it can help you. 1. Application of high temperature resistant PH tester The high temperature resistant PH tester consists of two parts: a pH sensor and a pH converter, and outputs a 4-20mA standard signal and sends it back to the instrument or PLC system for display or adjustment, and controls the process of adding acid or alkali The metering pump is used to adjust the pH of the incoming water to form an online pH measurement and adjustment system. 2. The composition of the pH sensor The pH sensor is commonly known as the pH probe, which consists of two parts: a glass electrode and a reference electrode. The glass electrode consists of a glass rod, a glass membrane, an internal reference solution, an internal reference electrode, an electrode cap, and wires. The reference electrode has a known and constant electrode potential, usually a calomel electrode or a silver/silver chloride electrode. Since the pH value is related to temperature, a temperature electrode is generally added for temperature compensation to form a three-electrode composite electrode. 3. The working principle of the PH sensor uses a hydrogen ion glass electrode and a reference electrode to form a primary battery. During the ion exchange process between the glass membrane and the hydrogen ions in the solution to be tested, the potential difference between the electrodes is measured to detect the pH in the solution. Hydrogen ion concentration, so as to measure the pH value of the liquid to be tested. 4. Installation of high temperature PH tester In order to detect the PH value of incoming water as early as possible, so as to obtain timely and effective control, high temperature PH tester is generally installed in front of the gate of the incoming water channel, with a buffer distance from the water treatment process. However, whether it is industrial sewage or domestic sewage, the water contains a lot of debris. If the sensor is directly installed in the water, the sensor glass bubble is easily broken by the debris in the water flow, causing damage to the instrument; or the glass bulb is damaged by debris. Winding, the true value of the water cannot be measured in time. Therefore, before the sensor is installed, protective measures must be taken first. Generally, an installation and operation platform is built at a place where there is room for pH adjustment in the incoming water channel, generally about 500m away from the gate plate, a DN100 caliber hole is opened in the middle of the platform, a DN100 stainless steel protection tube is taken, and several holes are placed at the lower end 1m Insert the pipe into the water from the opening of the platform for the eyelet with a diameter of 2cm, and immerse the eyelet in the water. Adjust the insertion depth of the pipe according to the depth of the canal. The bottom of the pipe should be 200mm to 300mm away from the bottom of the canal to avoid mud accumulation at the bottom of the canal. Pipe, the upper end of the pipe is fixed on the platform. After installing the sensor and the connecting rod, insert it into the protective tube. The insertion depth should be 100mm higher than the lower end of the tube, so as to prevent the sensor glass bulb from protruding from the protective tube and being damaged. The sensor cable passes through the connecting rod, and connects to the junction box of the converter according to the figure, and the installation is completed (as shown in Figure 2). Note that when installing the pH electrode, the protective cap on the electrode can only be removed when the electrode is in contact with water at all times. Otherwise, the electrode will dehydrate and fail. In order to facilitate maintenance, a sensor self-cleaning device is generally installed. There are two types of ultrasonic cleaning device and water cleaning device, because the water cleaning device has a set of solenoid valve control device, and also needs a clean water source, the installation is more troublesome, so it is generally recommended to use an ultrasonic cleaning device. 5. Routine maintenance of the high temperature resistant PH meter It can be known from the working principle that the electronic path between the working electrode and the reference electrode of the PH meter sensor is carried out through the measured medium, and the contamination of the glass film of the working electrode will directly affect the measurement. , especially in the application of sewage treatment plants, cleaning work is very important. Therefore, attention should be paid to: (1) Clean up the sundries around the probe protection tube once a day, so that the liquid in contact with the probe is the measured medium.