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1. Fixed Ultrasonic Flow meter product introduction
Fixed Ultrasonic Flow meter, based on the principle of velocity difference method, measures liquid flow inside a circular tube, which is suitable for relatively pure liquid flow outside the tube.Fixed Ultrasonic Flow meter integrates the company's technology and experience in manufacturing ultrasonic flow meters for more than ten years. It uses TI's MFP430FG4618 low-power microcontroller. It is a new ultrasonic flow meter product with high performance, low price, good reliability and powerful functions.
The product has been greatly improved compared to the original ultrasonic flowmeter in terms of measurement accuracy, measurement stability, communication protocol, ease of use, etc. At the same time, there is no adjustment of component parameters during the production process, the production process is simpler and more applicable, and the product consistency is better, thereby ensuring that every factory product reaches the best performance.
2. Working principle of Fixed Ultrasonic Flow meter
When an ultrasonic beam propagates in a liquid, the flow of the liquid will cause a slight change in the propagation time. The change in the propagation time is proportional to the flow rate of the liquid. At zero flow, the time required for the two sensors to transmit and receive the sound wave is exactly the same (the only Technology that can actually measure zero flow). When liquid flows, the sound wave transmission time in the countercurrent direction is greater than the sound wave transmission time in the downstream direction.
3. Product features of Fixed Ultrasonic Flow meter
In addition to the general functions of similar products, ultrasonic flow meters also have the following features:
1. The number of sampling times per cycle has been increased to 128, and the measurement results are more stable, which can meet the flow measurement needs of most clean water, sewage and various chemical liquids, and greatly reduce the interference of poor detection environment on the measurement results.
2. The use of electrically isolated DC power supply greatly improves the reliability and anti-interference performance of the host. For situations where there is no power supply on site, users can choose a 15W solar panel to connect to a 24V/30AH lead-acid battery pack, which can provide continuous power supply on cloudy days for a week.
3. The measurement motherboard is equipped with a standard isolated RF-485 interface, which can support both MODBUS and M-BUS standard protocols, and is fully compatible with the original ultrasonic flowmeter communication protocol and various flowmeter and water meter protocols produced by the company. .
4. The measurement main board is equipped with a serial expansion bus interface, and users can choose various function expansion modules to expand functions. Expandable functions include 4~20mA current loop output, frequency signal output, large-capacity data recording, thermal printer and other functions.
5. The main board has a two-way three-wire PT100 platinum resistance input circuit. When the platinum resistance is connected, it becomes a complete ultrasonic calorimeter. At the same time, a temperature difference sensitivity function is added to prevent the ineffective accumulation of heat during long-term low flow rates or low temperature differences.
6. The mainboard has three analog input circuits. Physical quantities such as pressure and liquid level can be input and used as a simple RTU.
7. A fault timer (located in menu M+9) has been added to the software operation window. When the instrument cannot measure normally, the time value will increase.
8. It has up to 8 different language interfaces for customers to choose from.
4. Technical parameters of Fixed Ultrasonic Flow meter
project | Performance, parameters | |
Host | Accuracy | 1.0% |
Repeatability | 0.2% | |
maximum flow rate | 6m/s | |
Measurement period | 500ms (2 times per second, collecting 128 sets of data per cycle) | |
Measurement principle | Ultrasonic time difference principle, 4-byte IEEE754 floating point operation | |
display interface | Can be connected to 2×10 backlit Chinese character or 2×20 character LCD display | |
operate | External 16-key touch keyboard and PC computer parameter software | |
enter | 3 channels of 4~20mA input are optional, with an accuracy of 0.1%. It can input signals such as pressure, liquid level, temperature, etc., and can also be used as a digital interface. | |
Two-way three-wire PT100 platinum resistance input circuit can realize heat measurement function (enthalpy difference method) | ||
output | Current signal (optional module): 4~20mA, impedance 600Ω floating, accuracy 0.1%. Frequency signal (optional module): optional between 1~9999Hz, OCT output. Pulse signal: positive, negative, net flow and heat accumulated pulses, dual OCT outputs (one of which has programmable pulse width between 6~1000mF, default 200mF). Alarm signal: dual-channel OCT output, nearly 20 source signals can be selected. Data interface: Isolated RF485 serial interface. | |
Communication protocol | MODBUS protocol, MBUS protocol, FUJI extended protocol (compatible with Huizhong Company’s flow meter and water meter communication protocol), it is recommended to use MODBUF-RTU protocol or MODBUS-ASCII protocol | |
Other functions | Automatically memorizes the cumulative flow rate and working status of the previous 64 days, the previous 32 months, and the previous 2 years; automatically memorizes the previous 16 power-on and power-off times and flow rates, and can realize automatic or manual replenishment; Programmable quantitative controller (can be started using external input signal or MODBUF instruction); One bidirectional serial interface can connect multiple external devices such as 4~20mA, data loggers, etc.; The working parameters can be solidified into the FLAFH memory inside the machine and automatically recalled when power is turned on; Users can upgrade software through code files sent by E-mail. Fault self-diagnosis function. Failure timer. | |
Working current | 50mA (when the keyboard display is not connected and the buzzer does not sound) | |
Standby current | Using CR2032, data can be maintained for 100,000 hours without loss under 24VDC power outage conditions. | |
ambient temperature | -10℃~70℃ (please contact the manufacturer for requirements above this temperature range) | |
working hours | continuous | |
sensor | Clamp-on type | M2 is suitable for pipe diameters DN50~700mm |
Signal cable | Specially designed, the factory standard configuration is 5 meters. A single length can be extended to more than 500 meters under certain circumstances (not recommended). | |
Protection level | IP68 (can work in water) | |
Testable pipeline | pipes | Steel, stainless steel, cast iron, PVC, PE, PPR copper, aluminum, cement pipes and other dense pipes are allowed to be lined (for plastics, try to keep the wall thickness less than 8mm, otherwise the measurement will not be possible if they are not dense). |
Lining material | Epoxy asphalt, rubber, mortar, polypropylene, polystyrene, polyester, polyethylene, hard rubber, bakelite, PTFE. | |
Straight pipe length | Upstream ≧10D, downstream ≧5D, distance from the pump outlet ≧30D. | |
Testable pipeline | type | Water |
Turbidity | ≦20000ppm, the sewage time measurement effect is good, and most sewage pipes can measure stably. | |
temperature | -40℃~160℃ | |
flow direction | The forward and reverse flow rates can be measured separately, and the net flow rate can be measured. |