Street flowmeter wiring, debugging method - Database & Sql Blog Articles

Today, I will talk about the wiring and debugging methods of street flowmeters.

1. Terminal block diagram Terminal function sensor transmitter power supply ++12 or +24VDC+24VDC power supply-0VDC0 VDC signal pulse signal empty ground connection shielded wire shielded wire 2. Wiring procedure Unscrew the case back cover and feed the signal cable from the waterproof connector. Wire the wiring correctly according to the wiring diagram. Tighten the waterproof joint and ensure that the cable must be bent down before entering the waterproof joint to ensure that moisture does not enter the housing along the cable. 3. Before powering up the vortex flowmeter on the meter, check whether the power supply voltage meets the requirements and check whether the electrical connection is correct. If everything is normal, it can be powered on. The instrument has been debugged and checked before leaving the factory. It can work normally after power-on. Commissioning and the use of pulse output type vortex flow sensor vortex flow sensor has been adjusted and calibrated before leaving the factory. However, due to the difference between the measured medium and the specified medium, there is a strong vibration in the field, and the detection amplifier needs to be adjusted. A. When there is no fluid flow in the measurement pipeline and there is still signal output in the display part, the potentiometer (W2) can be adjusted (clockwise) to reduce the output sensitivity so that the signal output due to pipeline vibration and the like is eliminated, but Do not rotate too much or it will cause signal loss when there is a small flow. B. When there is medium in the pipeline, if the signal is unstable at a small flow rate, the potentiometer W1 can be slowly adjusted to reduce the amplification factor until there is no multi-trigger signal. For the position and test point of the potentiometer, please refer to Figure A in Figure A: TP0 is connected to the ground, TP1 is the first-stage amplified output point, TP2 is the second-stage filter test point, TP3 is the output square wave test point, potentiometer W1 is the magnification adjustment and W2 is the trigger sensitivity adjustment. 4～20mA output type vortex flow transmitter 4~20mA standard signal output transmitter adjustment, two-wire 4～20mA output type transmitter consists of two boards: pulse output amplifier board and current output board, its signal sensitivity Adjust the preamplifier board still as shown in Figure 16A. The current output board is as shown in Figure 16B. W1 is the full potentiometer. When adjusting 20mA, it should correspond to the frequency corresponding to the upper limit flow of the pipe. W2 is the zero potentiometer. , corresponding to the frequency value corresponding to the lower limit flow of the pipeline. The position of the potentiometer is generally adjusted at the time of shipment, and the user does not need to adjust it without major changes. The battery-powered on-site display type vortex flowmeter shows that the vortex flowmeter is based on the basic vortex flow sensor, which is powered by battery and adds on-site display function. The flowmeter is a new type of flow measuring instrument integrated with sensors and display integration developed by advanced ultra-low power single-chip microcomputer technology. Compared with the traditional vortex flow sensor with secondary measuring instrument, it has small size, light weight, intuitive reading, clear, high reliability, free from external power supply, anti-lightning, low cost and other obvious advantage. It can be widely used in liquid flow measurement in petroleum, chemical, light industry, food and other industries. This product has superior performance and reaches the advanced level of international similar products. Built-in parameter setting of the instrument: (only authorized engineer operation) 01. Instrument panel key operation instructions Enter (exit) parameter setting menu: Simultaneous button and F key in working state; cursor position shift to the right: parameter setting state Press the cursor position value plus 1: In the parameter setting state, press the key parameter menu switch: press the F key in the parameter setting state; the accumulated flow clear: in the working state, press the F key and the key at the same time. 02. Internal parameter description The instrument program has three menus, which are displayed in three screens. All of them are three-point coefficient correction in the meter measurement range. The upper row is the flow point frequency value, and the lower row is the flow point meter coefficient. The three menus can be cycled with the F key. Display mode and function of each menu Note: The instrument parameters have been set before the instrument leaves the factory, no special circumstances need to be changed; using the three-point meter coefficient for nonlinear correction of the flow sensor requires the user to clearly know the different flow points (frequency points) of the sensor. Meter factor. 24VDC power supply on-site display type vortex flowmeter 24VDC power supply on-site display type vortex flowmeter is based on the on-site display type vortex flowmeter, adding 24VDC power supply, 4-20mA two-wire current transmission function, especially suitable for Display computer, industrial computer, DCS and other computer control systems are used together. It also has the function of on-site display and remote transmission. 01. Instrument panel button operation instructions with battery-powered on-site display type vortex flowmeter 02. Internal parameter description The instrument program has four menus, which are displayed in four screens. The first three menus are three-point coefficient correction in the meter measurement range, which is exactly the same as the battery-powered on-site display type vortex flowmeter; the fourth menu is 4-20mA. The full scale value (ie, the flow point corresponding to 20 mA) is output. The four menus can be cycled with the F key. The 1 to 3 menu display mode and function are the same as the battery-powered on-site display type vortex flowmeter. The fourth menu display mode and function Note: The instrument has been adjusted before the factory, and generally does not need to be adjusted. If under normal conditions of use, the output of the remote current does find that some points are out of tolerance with the theoretical value, adjust the adjustable resistance on the board as follows: open the front panel of the instrument, take out the board, at the most There are two adjustable resistors on the next layer of the board, of which V3 can be adjusted for 4mA, and V4 can be adjusted for 20mA. Note that the adjustment is not too large. After the adjustment, it is installed as it is. 03. Transmitter wiring: red line - 24V + black (green) line - 0V5. Operation and commissioning of temperature-compensated vortex flowmeter 01. Display panel and operation This type of display window has two rows of display and three rows of display specifications. The upper row of the main display page of the double row display panel displays the instantaneous flow rate, and the lower row shows the accumulated flow rate; the main display page of the three rows of display panels can display the pressure simultaneously. , temperature, instantaneous flow, frequency, cumulative flow, press the content button to display other parameters in turn. There are three buttons from left to right on the display panel: the left button displays the contents of the main display page in the working state, and changes the number of digits of the modified number (flashing word) in the parameter setting state; the middle button is displayed in the working state. Frequency, in the parameter setting state, the modified number (flashing word) is incremented cyclically; the right key is the content key, and each parameter can be cyclically displayed in the working state, and the function of confirming and turning the page is performed in the parameter setting state. In order to facilitate the determination of whether the flow is within the allowable range, the transmitter type will display a bar following the instantaneous flow change on the right side of the LCD screen. The upper limit of the bar represents the upper limit of the set flow rate, and the lower limit represents zero. In order to easily observe the amount of battery power, the battery-powered type will display a bar with the change of power on the right or bottom right side of the LCD screen. When the bar is short, the battery should be replaced in time. 02. The parameter display format and description picture are frequency display, the upper display indicator and the downlink display frequency value; the middle picture shows the output current display, the upper display indicator, and the downlink display output current value; the right picture shows the temperature display, the uplink display indicator, and the downlink display temperature value. . The picture shows the pressure display, the upper display indicator, the downward display pressure value; the middle picture is the compensation density display, the upper display indicator, the downlink display compensation density value; the right picture shows the density compensation mode, the uplink display indicator, and the downlink display compensation mode value. Ur is 1.00 for the set density, Ur is 2.00 for the pressure compensation density, Ur is 3.00 for the temperature compensation density, Ur is 4.00 for the temperature compensation density, and Ur is 5.00 for measuring the compressed air. The picture shows the set density display, the upper display indicator, and the lower limit display set density value; the middle picture shows the flow coefficient, the upper display indicator, and the downstream display flow coefficient value; the right picture shows the damping coefficient, the uplink display indicator, and the downlink display damping coefficient value. The value is valid from 1 - 9 and the larger the value, the longer the frequency sampling time. The figure shows the upper limit of the flow, the upper display indicator, and the downstream shows the flow value corresponding to the output fullness; the middle picture shows the small signal cutoff, the upper display mark, and the lower line shows the small signal cutoff value. When the flow rate is lower than the value, the instantaneous flow rate shows zero. The right picture shows the standard temperature setting, the upper display indicator, and the lower set display temperature value. At this time, dEn should be set to the density value corresponding to the standard temperature of the medium. This item is only suitable for measuring compressed gas. The temperature is limited to 0 - 100 ° C. When the temperature exceeds this range, the flow rate is calculated according to the standard temperature, indicating that the actual temperature is still measured. The picture shows the atmospheric pressure setting, the upper display indicator, the downward pressure shows the atmospheric pressure value; the middle picture shows the pressure upper limit setting, the upper display indicator, and the lower display pressure upper limit; the right picture shows the lower pressure setting, the upper display indicator, and the lower display pressure lower limit. The figure shows the cumulative flow clear setting, the upstream display indicator, and the downstream input is 4321.000 and confirmed, the accumulated flow can be cleared. This item is only applicable to the battery-powered type; the middle and right pictures are the full-scale and zero-point calibration settings. The item is only applicable to the transmitter type. When calibrating, the current meter is connected in series with the output circuit. The full scale and zero point of the output can be adjusted by changing the displayed number. 03. Press the right button and then press the middle button to enter the parameter setting state. At this time, the flashing word of the flow coefficient U appears on the display panel. Therefore, the flow coefficient (U), the damping coefficient (Lr), the upper flow limit (FH), and the lower flow limit (FL) can be sequentially completed by the shift of the left button, the change of the flashing word by the middle key, the confirmation of the right key, and the turning of the page. Set the parameters. For example, set the flow coefficient U to 123.45, first enter the setting state, press the right button to U-XXXXXX, then the first digit is flashing, press the middle button to make the first digit display 1, then press the left button and then press The key causes the second digit to display 2, and so on, until the last digit is set. After confirming that the setting number is correct, press the right button to confirm and display the next parameter setting. When all the parameters are set, press the right button and press the middle button at the same time to exit the setting state and enter the display state. • When the transmitter continuously presses the cumulative key five times while displaying the accumulated flow, the accumulated flow can be cleared to zero, and then the other keys are pressed to re-accumulate. ? Battery-powered type Set Un to 004321 to clear the accumulated amount; set Un to 001234 to automatically cycle display. Note: The unit of instantaneous flow rate and cumulative flow rate is the same as the upper and lower limit units of the set flow rate, and the flow rate signal below the flow rate lower limit is cut off. 04. How to use the DIP switch The signal processor of the transmitter adopts three sets of DIP switches SW1, SW2 and SW3, so that the same circuit can be applied to transmitters with different calibers and different media. For different calibers and media, turn the number corresponding to the DIP switches SW1, SW2, and SW3 to ON according to the following table (Table 9). The DIP switch near the signal line terminal is SW1, the middle is SW2, and the other is SW3. Code number SW1SW2SW3 gas, vapor-liquid gas, vapor-liquid gas, vapor-liquid 151,5 3,71514201,5 3,71514251,5 3,71514321,5 3,71514402,6 3,72524,5502,6 3,72626652,6 3,72616802,6 3,736371002,6 3,71,361,371252,6 3,72,36471502,6 3,746582003,7 3,7474,57,82503,7 4,84767,83003,7 4,847 , 867, 8 plug-in type 2, 63, 7262605. Internal calculation formula The measured medium working volume flow rate Q is calculated as follows: where F: output pulse frequency K: meter factor When the measured medium is steam or liquid medium, the working volume flow is converted into mass flow and calculated as follows: Where ρ(Kg/M3) is the measured medium density measured medium is a gaseous medium such as compressed air, and the volume flow rate of the working condition volume flow is converted into a standard condition (P=0.10136MPa; t=20 °C). Where P(MPa) is the gauge pressure of the measured medium under working conditions. The flowmeter's commissioning flowmeter has been debugged before leaving the factory and generally does not need to be adjusted. If you need to adjust, please refer to the relevant content in Chapters 2 and 5.