Intelligent electromagnetic flowmeter input and output and hardware system
Sun Mini Uv Led Lamp,12V Uv Light,Handheld Uv Lamp,Sun Mini Uv Lamp Guangdong Kingrate Optoelectronic Technology Co., Ltd. , https://www.kingrateuv.com
December 14 04:07:58, 2023
Because there is only a linear relationship between the data used by the smart electromagnetic flowmeter and the actual flow value, their units are not the same, and the flowmeter cannot directly use the collected data as the instantaneous flow data. It must be converted, the module is used to convert the collected data into flow data, because the outside world will have the effect of random interference, the data collected by the electromagnetic flowmeter system will sometimes deviate from the actual flow value. In order to obtain more accurate data, the system uses digital filtering to filter out the effects of interference before processing the data. During the actual measurement process of the electromagnetic flowmeter, there will be some phenomena. When there is no flow rate, external vibration and other signals can easily act on the sensor, which will introduce a signal with a wrong flow rate. This signal is lower than the lower limit of measurement of the electromagnetic flowmeter, but it will also be accumulated. Moreover, when the normal flow rate of traffic exceeds, this weak signal will be submerged and will not affect the measurement. To avoid the occurrence of a false flow signal, we will set a cut-off signal within the lower limit range. When the electromagnetic flowmeter measurement signal is lower than the signal, it will be considered as a flow error signal, and the instantaneous flow rate will be treated as zero. When the cumulative flow rate does not accumulate and the introduction signal is higher than the signal, it will be considered as Normal traffic signal.
In order to further improve the filtering effect of the electromagnetic flowmeter, a new filtering method is adopted, that is, a combination of a median filtering method and an average filtering method. This filtering method is called a composite filtering. Filtering, etc., is then sampled by the converter and input to the SCM system. Then the flow-related data is set through the keyboard interface, and then various measured values ​​(flow direction indication, instantaneous flow, forward and reverse cumulative flow, etc.) are displayed on the LCD. At the same time, it also provides the necessary excitation control signals for the system. The design idea is: continuous sampling N times, the sampled values ​​are queued in order, after the maximum and minimum values ​​are removed, the samples are averaged. In this way, both pulsed interference and slow random fluctuation signals can be removed. The system's sensor consists of a pair of excitation coils and a pair of symmetrically distributed detection electrodes. And it is sent to the signal processing circuit for processing. The signal processing circuit amplifies the signal input by the sensor and generates an induced magnetic field after the coil is energized, and the fluid is used to cut the magnetic force line to move, and thus an induced electromotive force (measurement signal) is generated on the electrode.
Electromagnetic flowmeters use signals to determine filtering because of random signals, false detections, or transmitter instability. The program determines that the filter is based on production experience and determines the maximum deviation that may occur for two consecutive input signals. If it exceeds the deviation value, it is considered to be a false interference signal, otherwise the sample value must be retained. Intelligent electromagnetic flowmeter basic program is relatively good judgment, which can also be divided into limiting and speed limit two ways, in the electromagnetic flowmeter filter, you can experiment to select the appropriate value until the signal is not detected Obvious ripple so far. The average filter method was found to be suitable for smoothing traffic signals. The flow signal always fluctuates within a certain range of values. There is an average value. The sampling point is inaccurate, and the degree of smoothness depends. With increasing, the smoothness increases, but the response speed decreases. The converter is installed not too far away from the sensor. It amplifies and converts the flow signal sent from the sensor into a unified, standard current output signal or digital communication output signal, which is provided for the lower indicator, recording, regulating instrument or Computer network to display, accumulate, and regulate control management of traffic signals.