Instrumentation is one of the important resources for many occasions and processes such as production process, quality inspection, and experimental analysis. As the name suggests, instrumentation is used for measurement or inspection, and is the source of various production data to ensure the normal and stable production. Therefore, the instrument The stable and reliable operation of the instrument is an important work in production, so what kind of maintenance means can ensure the accuracy of the detection data of the instrument?
Under normal circumstances, we will perform periodic verification, calibration, and periodical inspections on instruments and equipment, but in addition to this and periodic inspections, we should also do a good job in the daily maintenance of instruments and equipment. Let's briefly talk about the necessity of instrument maintenance.
Instruments and meters are precision production test equipment. They are generally composed of precision parts and circuit boards. These parts and circuit boards are easily interfered by the external environment, such as dust, water mist, and light. , Microelectronics, magnetic field and other factors, these factors can easily affect the measurement results of the instrument. The daily maintenance of the instrument is the need to protect the instrument and reduce the failure rate of the instrument. During the use of the laser ranging instrument, not only is it affected by the external environment, but its internal components are aging or overloaded, which will cause the equipment to operate abnormally and incorrectly. If it is some instruments used in safety inspection, once there is a problem, the consequences will not be known. Doing a good job in daily maintenance can very effectively reduce the incidence of these accidents. Intelligent electromagnetic flowmeter is a commonly used flow meter in industrial production. To obtain stable and reliable flow data, we cannot do without the stable operation of intelligent electromagnetic flowmeter. For the daily maintenance of intelligent electromagnetic flowmeter, we mainly master the following aspects:
1. Zero point inspection and adjustment of intelligent electromagnetic flowmeter maintenance
Before the intelligent electromagnetic flowmeter is put into operation, the zero point must be adjusted when the electromagnetic flow sensor is still full of liquid after power on. After putting it into operation, it is necessary to periodically stop the flow for zero-point inspection according to the operating conditions; especially for the precipitation, easy to pollute the electrode, and the non-cleaning liquid containing solid phase, more inspections should be made at the beginning of the operation to obtain experience to determine the normal inspection cycle. Compared with rectangular wave excitation, the intelligent electromagnetic flowmeter of AC excitation mode is more prone to zero drift, so more attention should be paid to inspection and adjustment.
Give two examples of application errors in which the deposition layer fails. One is that in oil drilling and cementing projects, the total flow of cement slurry is an important process parameter, and high-pressure electromagnetic flowmeters are often used. The meter is used intermittently. After use, rinse the sensor measuring tube with clean water, and the rest of the time is empty. Due to the incomplete cleaning, the residual cement slurry on the inner wall of the measuring tube solidified into a thin layer, which accumulated in the past two months to form an insulating layer, which covered the entire electrode surface, resulting in abnormal operation and eventually unable to work.
The other is the electrolytic cutting process testing device, using an intelligent electromagnetic flowmeter to control the flow of saturated brine. After using the gap for a period of time, the flow signal is found to gradually weaken, and the signal is zero after 2 months. The reason is that iron oxide deposits on the pipe wall during the electrolytic cutting process, forming a short circuit. Clear the stratification and immediately return to normal.
2. Regularly check the electrical performance of the sensor during maintenance of the intelligent electromagnetic flowmeter
First, roughly measure the resistance between the electrodes. Disconnect the signal connection between the sensor and the converter, the sensor is filled with liquid, and use a multimeter to measure the resistance of the two electrodes and the grounding terminal to see if they are within the range specified by the manufacturer, and the measured values are roughly the same. Record the measured resistance value. This value is useful for later determining the cause of sensor failure (such as whether the deposited layer is conductive or insulating).
Secondly, empty the sensor, wipe the inner wall, and measure the resistance between the two electrodes and the ground terminal with a megohmmeter after it is completely dry.
After that, check the insulation resistance of the excitation coil, remove the excitation coil of the sensor, connect the terminal and the converter, and measure the insulation resistance of the coil with a megohmmeter.