STDS100 fixed external clamp ultrasonic flowmeter

Select installation point

§ 1.1Working condition requirements

The installation of ultrasonic flow meters is the simplest and most convenient among all flow meters. Simply select a suitable measurement point, input the pipeline parameters at the measurement point into the flow meter, and then fix the sensor on the pipeline.

Choosing the installation point is crucial for accurate measurement, and the following factors must be considered when selecting the installation point: full pipe, steady flow, scaling, temperature, pressure, interference, etc.

1. Full tube: Choose a material filled with fluid that is uniform and dense, 2Steady flow: The installation distance should be greater than 10 times upstream

Pipe sections that are easy to transmit ultrasonic waves, such as vertical pipe sections (with fluid flowing towards the straight pipe diameter and downstream diameter greater than 5)There are no bends within the diameter of the double straight pipe

Upward flow) or horizontal pipe segments. The installation point of a uniform straight pipe section with variable diameter should be located away from the valve

Interference sources such as pumps, high-voltage electricity, and frequency converters.

3. Avoid installing it at the highest point of the pipeline system or at any other locationFor open or partially filled pipelines, flow meters should

Installed on the vertical pipeline at the outlet (with fluid flowing downwards) in UAt the section of the pipe.

5. The temperature and pressure at the installation point should be within the working range of the sensor.

6. Fully consider the scaling condition on the inner wall of the pipe: even if a pipeline without scaling is selected for installation, if it cannot meet the requirements, scaling can be considered as lining for better measurement accuracy

7. Two sensors must be installed in the horizontal direction of the pipeline axis, and at a horizontal position of ± 45 ° on the axisInstall within the range to prevent phenomena such as incomplete pipes, bubbles, or sedimentation in the upper part, which may affect the normal measurement of the sensor. If the installation location is limited by space and cannot be installed horizontally symmetrically, sensors can be installed vertically or at an angle while ensuring that there are no bubbles in the upper part of the pipe.

Example of probe installation point

§ 1.2Construction requirements for installing sensors in instrument wells

If the on-site sensor needs to be installed in the instrument well, there must be a certain installation space for people to work upright, that is, the distance between the pipe wall and the wall should be at least 550mmAbove, the width W is greater than (D+550 × 2) mm, the cement pipeline W is greater than (D+700 × 2) mm, and the axial width L of the instrument well is greater than D+1200mm. When installing sensors, flanges, welds, and reducers should be avoided, and they should be installed as much as possible within the horizontal position of the pipeline axis ± 45 °, and then the main engine housing should be grounded.

2. Quickly complete initial settings

The ultrasonic flowmeter needs to input the following parameters before measurement:

　1. type inM 1 1 Enter the outer diameter of the tube in window 11 and typeENTKey;

　2. type in-Enter the thickness of the pipe wall in window 12 and typeENTKey;

　3. type in-Enter window 14ENT，+Or-After selecting the pipe material, type inENTKey;

　4. type in-Enter window 16ENT，+Or-After selecting the lining material, type inENTKey;

　5. type in-Enter window 18ENT，+Or-After entering the thickness of the lining material, type inENTKey;

　6. type in-Enter window 20ENT，+Or-After selecting the fluid type, type inENTKey;

　7. type in-Enter window 23ENT，+Or-After selecting the sensor type, type inENTKey;

　8. type in-Enter window 24ENT，+Or-After selecting the installation method, type inENTKey;

　9. type in-Enter window 25ENTInstall the sensor according to the displayed installation distance and the installation method selected in the previous step.

　10. M 4 0 Damping coefficient. (Default 10 seconds, generally no need to change)

　11. M 4 1 Low flow rate cutting treatment. (Factory default value of 0.03m/s, generally does not need to be changed)

　12. M 2 6 Enter window 26,+Or-Select "1 Curing Parameters and Always Use"”Then type inENTKey (this operation is very important).

　13.type inM 9 0 Enter window 90 and check the signal strength and quality. The minimum is above 60.0, the larger the better. If it is below 60, normal operation cannot be guaranteed;

　14. type inM 9 1 Enter window 91 and check the signal transmission time ratio. Generally, it is required to be within 100 ± 3;

　15. type inM 0 8 Enter window 08, check the machine's working status, and display * R as the signal is normal;

16. type inM 0 1 Enter 01The window displays the measurement results;

Three installation measurements

§ 3.1Host wiring diagram

§ 3.2Install sensors

There are three types of fixed ultrasonic sensors for users to choose from: external clamp type, insertion type, and pipe segment type.

There are two installation methods for external clamp sensors, namely: VLaw, Z method

The installation method of the plug-in sensor adopts Zlaw

The installation of the segmented sensor only requires the customer to select the installation point, cut off the pipe on site, and install the flange connection

The following are respectively used as introductions

§ 3.2.1External clip sensor

Before installation, the dense part of the pipe should be selected for sensor installation. Then, the area outside the pipe where the sensor is to be installed should be cleaned, and rust and paint should be removed. If there is a rust proof layer, it should also be removed. It is best to use an angle grinder to polish it, and then use a clean cloth dipped in acetone or alcohol to wipe off oil and dust. Then, apply enough coupling agent to the pipe wall around the center where the sensor is to be installed. Finally, press the sensor tightly against the pipe wall and follow the instructions of 24The installation method displayed in menu 3.2.1.1 and the installation distance displayed in menu 25 should be bundled together. Be sure not to have air bubbles or gravel between the attached sensor and the pipe wall.

§ 3.2.1.1Installation method

The installation method of external clamp sensors includes VLaw and Z method. (See installation diagram for details)

In general, the installation pipe diameter is between DN15-DN200mmWithin the range, the V method can be preferred. When the V method cannot measure the signal or the signal quality is poor, the Z method can be used. When the pipe diameter is above DN200mm or when measuring cast iron pipes, the Z method should be preferred.

Vlaw

Normally, VFa is a relatively standard installation method that is easy to use and accurate in measurement. During installation, the two sensors should be aligned horizontally, with their center lines aligned with the pipeline axis. The measurable pipe diameter range is approximately DN15-DN40mm.

Zlaw

ZLaw is the most commonly used installation method, characterized by direct transmission of ultrasonic waves in pipelines without reflection (known as single acoustic path), and minimal signal attenuation loss.

ZThe measurable diameter range of the method is DN50mm-DN6000mmWhen installing on site, it is recommended to use the Z-method for pipelines with a diameter of 200mm or more (as this will result in the highest measured signal).

matters needing attention:

1. During installation, the pipeline area where the sensor is to be installed must be cleaned thoroughly to expose the original luster of the metal;

2. The shielding wire of the ultrasonic signal cable can be suspended without connection, and should not be short circuited with the positive and negative poles (brown and blue wires);

3. After the sensor is wired, it must be filled with sealant (silicone) to prevent water from entering;

4. After filling the sensor with sealant and covering it, the shielded cable inlet hole of the sensor must be tightened and locked to prevent water from entering;

5. When bundling sensors, the fixture should be attached（The stainless steel strip is fixed at the center of the sensor to ensure uniform force distribution and prevent sliding;

6. The contact area between the sensor and the pipeline should be coated with sufficient coupling agent or silicone to prevent air, dust, or rust from entering and affecting the transmission of ultrasonic signals.

§ 3.2.2plug-in sensor

There are three types of plug-in sensors to choose from:

When the installation pipeline material is carbon steel or stainless steel, it can be directly welded for installation. For pipelines that cannot be directly welded, such as cast iron, fiberglass PVCSpecial pipe clamps made by the manufacturer are required for installation of cement pipes, etc. If the user encounters this type of situation when ordering, please inform the manufacturer of the precise outer diameter of the pipeline to be installed to prevent water leakage.

§ 3.2.2.1Installation tools

Installation of plug-in sensors requires the use of specialized hole positioning tools, 400WHand drills (preferably with high-level adjustable speed), wrenches, and screwdrivers.

§ 3.2.2.2Installation distance

The installation spacing of plug-in sensors is based on the distance between the centers of the two sensors along the pipe axis direction. The calculation method for the spacing is to first enter the required parameters (two initial parameter settings) in the menu, and then view window 25Install the sensor according to the displayed number.

§ 3.2.2.3Installation method

There is only one installation method for plug-in sensors, which is ZUsually, pipes with a diameter of DN80mm or more can be used.

§ 3.2.2.4Installation point positioning

Input the pipeline parameters into the host and calculate the installation distance (L)=Inner diameter -9.113mm), then determine the positions of the two sensors based on the installation distance (the two sensors must be ensured to be on the same axis), and the installation distance is the center distance between the two sensors.

1、 Making positioning paper: Take a 4D long stripA rectangular paper bag with a diameter of 200mm (or D) (depending on the site conditions, moisture-proof and corrosion-resistant materials can be used instead of the paper bag), draw a line about 100mm from the edge (as shown in Figure 1)

2、 Wrap the positioning paper around the cleaned surface of the official road, paying attention to aligning the two sides of the paper so that the drawn line is parallel to the pipe axis (as shown in the figure)

3、 Extend the straight line on the positioning paper and draw a straight line on the pipeline. The intersection point between the drawn line and one edge of the positioning paper is A(As shown in the picture)

4、 From AStarting from the point, measure 1/2 of the circumference of the pipeline along the edge of the positioning paper. The parallel intersection point is C. Draw a straight line parallel to the pipeline axis at point C (i.e. parallel to the straight line on the positioning paper) (as shown in the figure)

5、 Remove the positioning paper and start from point CAt the beginning, measure the installation distance L on the drawn line to determine point B. This way, points A and B are the installation positions; For example, L=280mm (as shown in the figure), weld the ball valve base to points A and B respectively, and make sure that the center point of the ball valve seat coincides with points A and B.

§ 3.2.2.5. Welded ball valve base

For weldable pipes (such as steel, stainless steel, etc.), simply weld the ball valve base directly onto the outer wall of the pipeline. Before welding, the surface of the pipeline near the welding point must be cleaned to remove rust and paint. If there is a rust proof layer, it should also be removed. Use a cloth dipped in acetone or alcohol to wipe off oil and dust, and then weld. However, it is necessary to ensure that the center point of the ball valve base is aligned with AOverlap with point B, be careful not to introduce air holes during welding to prevent water leakage or even breakage.

For non weldable pipes (such as cast iron, cement pipes, etc.), customized specialized pipe clamps (with sealing gaskets) need to be used for fixation. The ball valve base has been welded to the pipe clamp in advance, and the pipe clamp is directly fastened to the tested pipeline to ensure that the center point of the ball valve base is aligned with AAlign with point B and secure the ball valve base to the outer wall of the pipeline, making sure to seal it properly to prevent water leakage. Then place a PTFE pad on the ball valve base and screw on the ball valve.

§ 3.2.2.6 boreholes

Connect the sealing sleeve of the hole opener to the external thread of the specially designed ball valve, tighten it, open the ball valve, push the drill rod until it contacts the outer wall of the pipeline, connect the handheld drill to the drill rod and lock it, turn on the power, and start drilling. During the drilling process, the drill should maintain a low speed and not too fast, so as not to get stuck or even break the drill bit. After drilling through, pull out the drill rod until the front end of the hole opener drill bit retreats to the ball valve core, close the ball valve, and remove the hole opener.

§ 3.2.2７Inserting the sensor into the installation

Rotate the locking nut to the bottom of the sensor and push the sensor into the specially designed ball valve. When the ball valve core is reached, open the ball valve and directly push in the sensor until the front end of the sensor extends out of the inner wall of the pipeline. Adjust the angle of the sensor (the direction of the sensor emitter is consistent with the direction of the inlet hole, so when installing two sensors, the inlet holes should be kept opposite), tighten the locking nut, and finally connect the wire. Seal the wiring with silicone rubber.

Calculation of the size of the sensor extending into the inner wall of the pipe (see figure below)

The plug-in sensor is precision cast with a stainless steel mold, and the length of the sensor is AGiven the fixed value of A at the factory and the thickness of the pipe wall B, the sensor can also measure the length L left on the outside of the pipeline, as long as L=A-B and C=0.

Length A of each modelValue: Standard Insertion Type B: A=170mm Standard Insertion Type C: A=220mm

Cement insertion BType: A=310mm

§ 3.2.2.8 Sensor wiring

After installing the internal identification wiring of the junction box, tighten the nut of the wire inlet hole (be careful not to lose the sealing gasket), and finally tighten the cover tightly to prevent water leakage.

§ 3.2.2.９ maintenance

The maintenance of plug-in sensors is very simple. Simply follow the reverse installation process to remove the old sensor and replace it with a new one.

matters needing attention:

　　1. During the welding process of the ball valve base, it is necessary to avoid phenomena such as slag inclusion, sand holes, and water seepage;

　　2. The welding of the two ball valve bases must ensure that they are on the same axis to prevent poor reception of ultrasonic signals;

　　3. After opening the hole, it is necessary to clean the iron filings and other debris inside the ball valve to prevent thread adhesion, jamming, and other phenomena when the sensor probe rod is screwed in.

　　4. It is necessary to ensure that the ultrasonic signals emitted from the front ends of the two sensors are facing upwards (i.e. the inlet holes of the two sensors are consistent); 5. After installing the sensor, be sure to tighten the locking nut to prevent the sensor from loosening;

6. After connecting the wires, make sure to tighten the sealing cover to prevent water from entering.

§ 3.2.3Pipe segment sensor

　　Pipe segment sensors have the characteristics of high measurement accuracy and simple installation. According to the actual situation on site, users need to customize with the manufacturer in advance and provide actual pipeline parameters. The manufacturer sets the parameters into the machine before leaving the factory, so there is no need to input parameters for on-site installation. Only select the installation point, cut off the pipe, and weld the flange.

§ 3.2.3.1Sensor wiring

After the wiring of the split type pipe section is completed according to the internal identification of the junction box, tighten the nut of the inlet hole (be careful not to lose the sealing gasket), and finally tighten the cover tightly to prevent water leakage.

Customers of integrated pipe sections do not require wiring.

§ 3.2.3.2Sensor specifications

DN32~DN300Carbon steel flange connection unit: mmNominal pressure: 1.6Mpa

DN350~DN600Carbon steel flange connection unit: mmNominal pressure: 1.0Mpa

DN700~DN1000Carbon steel flange connection unit: mmNominal pressure: 0.6Mpa

§ 3.3power on

After the ultrasonic flowmeter is powered on, first run the self diagnostic program. If there is a fault, the corresponding error message will be displayed (see the fault finding section). After diagnosis, the machine will operate according to the parameters entered by the user last time.

Keyboard operation does not affect the measurement process, as the instrument uses time-sharing technology for parallel processing internally. Measurement, computation, typing, display, printing, serial port operation, input/output, etc. are all referred to as“Events "are independent of each other. For example, modifying the date by the user will not affect any other business unrelated to the date and time.

When powered on, if the machine is already installed, start from M01The window shows that the machine is adjusting the amplifier gain. After four steps S1, S2, S3, and S4 are displayed in the upper left corner of the monitor, the machine automatically enters the normal measurement state.

If it is the first time using or installing in a new installation location, the pipeline parameters of the new installation location need to be entered. Any parameters entered by the user are recorded in RAMInternally, power failure will result in loss. If permanent storage is required, please enter menu 26 and select 1 curing parameter.

When the user changes the parameters, the machine will automatically recalculate and adjust according to the new input parameters. The ultrasonic flowmeter can complete all tasks simultaneously, regardless of which display window it is on. Measurement, output, and other tasks will proceed as usual.

The fixed ultrasonic flowmeter automatically enters the display window it was in before the last power outage after each power on.

§ 3.4Check installation

Checking installation refers to checking whether the sensor is installed properly and whether it can receive correct, strong enough ultrasonic signals that can make the machine work normally, in order to ensure the long-term reliable operation of the machine. By checking the received signal strength, total transmission time, time difference, and transmission time ratio, it can be determined whether the installation point is optimal.

The quality of installation directly affects whether the flow value is accurate and whether the flowmeter can operate reliably for a long time. Although in most cases, measuring results can be obtained by simply coating the sensor with coupling agent and attaching it to the outside of the pipe wall, the following checks still need to be performed to ensure the best measurement results and ensure the long-term reliable operation of the flowmeter.

§ 3.4.1Signal strength

Signal strength (M90)The middle display refers to the strength of the signals received by the probes in both upstream and downstream directions. The relative signal strength of ultrasonic signals is represented by numbers ranging from 00.0 to 99.9. 00.0 means no signal received; 99.9 represents the maximum signal strength.

During installation, try to adjust the position of the sensor and check if the coupling agent is sufficient to ensure maximum signal strength. The condition for the system to function properly is that the signal strength in both directions is greater than 60.0When the signal strength is too low, the installation position, spacing, and pipeline of the sensor should be rechecked for suitability or replaced with Z-method installation. In general, the stronger the signal strength and the more stable the measurement value, the more reliable it can operate for a long time.

§ 3.4.2Signal quality (Q value)

Signal quality abbreviated as QThe value (displayed in M90) refers to the quality of the received signal. 00 indicates the worst signal, 99 indicates the best signal, and generally requires a signal of 60 or above.

The reasons for poor signal quality may be high interference, poor sensor installation, or the use of poor quality, non specialized signal cables. In general, the sensor should be repeatedly adjusted to check if the coupling agent is sufficient until the signal quality is maximized.

§ 3.4.3Total transmission time and time difference

Window M93The "total transmission time and time difference" displayed in the flow meter can indicate whether the installation is appropriate, because the internal measurement calculation of the flow meter is based on these two parameters. Therefore, when the "time difference" indication fluctuates too much, the displayed flow rate and velocity will also jump sharply. This situation indicates poor signal quality, which may be due to poor pipeline conditions, inappropriate sensor installation, or incorrect parameter input. Under normal circumstances, the fluctuation of time difference should be less than ± 20%. But when the pipe diameter is too small or the flow rate is very low, the fluctuation of time difference may be slightly larger.

§ 3.4.4Transmission time ratio

The transmission time ratio is used to confirm whether the sensor installation spacing is correct. The transmission ratio should be 100 ± 3 when installed correctlyThe transmission time ratio can be viewed in M91.

When the transmission ratio exceeds 100 ± 3When determining the range, it is necessary to check whether the input parameters (pipe outer diameter, wall thickness, pipe material, lining, etc.) are correct, whether the installation distance of the sensor is consistent with the data displayed in M25, whether the sensor is installed on the same axis of the pipeline, whether there is too thick scaling, and whether the pipeline at the installation point is elliptical deformed.

§ 3.4.5Precautions during installation

　　1）The input pipeline parameters must be correct and consistent with the actual situation, otherwise the flowmeter cannot work properly.

　　2）When installing, use enough coupling agent to stick the sensor to the pipeline wall. While checking the signal strength and signal quality values displayed by the host, slowly move the sensor near the installation point until the strongest signal and maximum signal quality value are received. The larger the diameter of the pipeline, the greater the range of sensor movement. Then confirm whether the installation distance matches the sensor installation distance given by M25, and whether the sensor is installed on the same straight line as the pipeline axis. Pay special attention to pipes made of rolled steel plates, as these pipes are irregular. If the signal strength is always marked as 00.0, it indicates that the flowmeter has not received the ultrasonic signal. Check whether the parameters (including all parameters related to the pipeline) are input correctly, whether the installation method of the sensor is selected correctly, whether the pipeline is too old, whether its lining is too thick, whether there is fluid in the pipeline, whether it is too close to the valve elbow, and whether there are too many bubbles in the fluid. If it is not for these reasons, the signal cannot be received, so we have to try another measurement point or choose a plug-in sensor.

3）Confirm whether the flowmeter is working properly and reliably: the higher the signal strength, the better the signal qualityThe higher the value, the higher the credibility of the displayed flow value, and the more reliable the flow meter can work for a long time. If the environmental electromagnetic interference is too large or the received signal is too low, the reliability of the displayed flow value will be poor, and the possibility of long-term reliable operation will be small.

　　4）At the end of installation, the instrument should be powered on again and the results checked for accuracy.

§ 3.5How to achieve heat measurement

Ultrasonic flowmeter/The heat meter can be connected to a three wire PT100 or a two wire PT1000 to achieve heat measurement. The wiring method is as follows:

OnePT100wire connection

Functional ultrasonic heat meter:External wiring can refer to the markings inside the junction box; The power supply and signal terminals of the internal wiring water supply circuit temperature sensor are respectively connected to terminal T1， On TX1. The power supply terminal and signal terminal of the return water circuit temperature sensor are respectively connected to the terminal blocks T2 and TX2. Connect the ground terminals of the two resistors together to the GND terminal.

●Split type ultrasonic calorimeter:The power supply and signal terminals of the temperature sensor in the water supply circuit are respectively connected to T1 on the right side of the circuit board， On TX1, the power supply and signal terminals of the return water circuit temperature sensor are respectively connected to terminal T2 and TX2. Connect the ground terminals of the two resistors together to the GND terminal.

●Ultrasonic thermal module:The power supply terminal and signal terminal of the temperature sensor in the water supply circuit are respectively connected to the wiring terminal T1 above， On TX1, the power supply and signal terminals of the return water circuit temperature sensor are respectively connected to terminal T2 and TX2. Connect the ground terminals of the two resistors together to the GND terminal.

IIPT1000wire connection

Battery powered ultrasonic heat meter:The power supply and signal terminals of the temperature sensor in the water supply circuit are respectively connected to the TPJ on the circuit board， On GND. The power supply terminal and signal terminal of the return water circuit temperature sensor are respectively connected to the terminal TPC and GND.

matters needing attention:

1.When extending the connection of temperature sensors, it is advisable to use wires with thicker diameters as much as possible, and ensure that all three wires connecting temperature sensors are of the same specifications and are identical.

2.The temperature measurement circuit and the flow measurement circuit are grounded together.