This paper summarizes the main causes of the problem of the liquid level meter, mainly related to the following aspects:
(1) the problem of selection. Some of the vortex sensor in caliber selection or due to changes in process conditions in the design selection, making the choice of a large size, the actual selection should be chosen as small as possible. In order to improve the measurement accuracy, the main reasons for this problem, the same, the relevant. For example, a vortex pipeline designed for several devices used as part of the equipment process does not use sometimes, resulting in the current actual flow rate decreases, the actual use of the original design and selection of large caliber, lower equivalent to improve the testability, process piping with small flow indicator can not be guaranteed, large flow can also be used for if you want to reinvent too difficult (sometimes. The process conditions of change is only temporary). The re tuning of the parameters can be combined to improve the accuracy of indication.
(2) installation problems. The length of straight pipe in front of the sensor is not enough, which affects the measurement accuracy. For example: two according to the FIC203 sensor in front straight segment is obviously insufficient, because FIC203 is not used for measurement, only for the control, so the current precision can be used (equivalent to downgrade use).
(3) the reason of parameter setting direction. Due to the error of the parameters, the error of the instrument indication is wrong. The error of the instrument makes the error of the two meter full. Full frequency similar indication because of the long-term to make the actual full frequency of frequency calculation indicates a wide range of big fluctuations, not reading, and inconsistent data on the parameters and the impact of the determined parameters, finally through the combination of re calibration are compared with each other to determine the parameters, to solve the problem.
(4) failure of the two meter. This part of the fault is more, including: a broken instrument circuit board, a display range setting some bad, K coefficient set individual bits display bad, which cannot be determined the range setting and K coefficient, this part mainly to the problems, the. The problem can be solved by repairing the fault.
(5) connection of four circuit. Part of the loop on the surface line connection is good, check carefully, some actual joint loosening caused by circuit interruption, although some joint connection is very tight but due to side line fastening screw in fastening line but also makes the skin, the loop is interrupted, this part mainly with the related problems. The corresponding circuit problem is solved, and the existing problems are solved accordingly.
(6) the connection between the two meter and the following instrument. As a result of the follow-up instrument or due to the subsequent instrument maintenance, so that the two meter mA output circuit interruption, for this type of two meters, this part of the main reasons for the problem. Especially for the follow-up of the recorder, the recorder can not be repaired in the case of long-term damage, we must pay attention to the output of the two meter short.
(7) the loop is always out of order because of the failure of the two meter level cable. Due to the long-term operation, coupled with the impact of dust, resulting in the failure of the flat cable, through the cleaning or replacement of flat wire, the problem can be solved.
(8) for the problem is mainly due to the two meter display meter coil fixing screw loose, causing head sinking, pointer and friction case, action is ineffective, by adjusting the header and re fixed, the corresponding problem solving.
(9) the use of environmental issues. In particular, the sensor installed in the ground, due to the high humidity of the environment, resulting in wet circuit board, this part of the main reasons. Through technical measures, the environmental humidity sensor part of re made the probe part and the conversion part separation treatment, instead of the separate type sensor, so the good working environment, before the date of this part of instrument is running well.
(10) due to the lack of adjustment on the spot, or the change of the actual situation after the adjustment. Due to the vibration and noise of balance adjustment and sensitivity adjustment is not good. Or because of running after a period of time after the adjustment of the field change again, causing problems, this part mainly indicates the same problem, the relevant. Using oscilloscope, combined with the operation of the process, re adjust.