Industrial Ultrasonic Flow Meter System Theory
Ultrasonic flow meters are volumetric flow meters that are used to measure the flow rate of liquids, gases, or steam. They are commonly found in oil and gas, pharmaceutical, and food and beverage industries. Flow meters use time of flight or doppler techniques to measure flow rate.
Flow meters that use the time of flight principle have a pair, or multiple pairs, of transducers. The transmit time of the ultrasonic waves is measured in both directions and from this the flow rate can be calculated. This technique typically requires a relatively pure medium, with <5% particles. Accuracies of <1% are achievable.
Using the doppler approach, ultrasonic pressure waves are reflected off of moving particles in the flow. The velocity of these particles creates a doppler shift in the echo signal, which is used to determine the flow rate. This measurement approach is typically limited to 3% accuracy in real-world implementations.
An ultrasonic flow meter consists of power supplies, transducer excitation, signal conditioning, ADCs, processing, a display, a keypad, and multiple communication options, such as 4 mA to 20 mA, HART, RS-485, and wireless.
This solutions guide will focus on ultrasonic flow meters based on the time of flight principle. The signal chain below is best suited for applications requiring higher performance, especially those with multiple pairs of transducers. As well as the need to achieve high measurement accuracy, these designs often have significant space constraints.
In liquid ultrasonic flow meters, a 1 MHz ultrasonic frequency is common. The accuracy of the system is directly related to the relative accuracy of the upstream and downstream time of flight measurements. For this reason, an FPGA is generally used to control the timing of the transmit and receive pulses. Careful attention must also be paid to any possible variations in latency of the transmit and recieve signal paths.
Another important aspect is the high gain required by the receive signal chain. This gain needs to be dynamically adjustable for different flow conditions and pipe sizes, typically in the range of 60 dB or higher, thus requiring a low noise receive signal chain path.
The transducer excitation can be either be on/off or a waveform generator may be used. A waveform generator typically adds cost and complexity, but provides greater control of the output signal allowing for an even more accurate and robust flow meter design.
The signal processing requires considerable filtering and FFT analysis to determine a precise time-stamp for the receive signal, which can be done using a DSP processor that can also support the required interface protocols.
| 零件編號 | 描述 | |
|---|---|---|
| AD8332ARUZ Analog Devices Inc. |
線性 - 放大器 - 特殊用途, IC VGA DUAL W/PREAMP LN 28-TSSOP | RFQ |
| AD8332ARUZ-R7 Analog Devices Inc. |
線性 - 放大器 - 特殊用途, IC AMP VAR GAIN 2CHAN 28TSSOP | RFQ |
| AD8338ACPZ-RL Analog Devices Inc. |
線性 - 放大器 - 儀表、運算放大器、緩衝放大器, IC OPAMP VGA 18MHZ 16LFCSP | RFQ |
| AD8338ACPZ-R7 Analog Devices Inc. |
線性 - 放大器 - 儀表、運算放大器、緩衝放大器, IC OPAMP VGA 18MHZ 16LFCSP | RFQ |
| AD5700-1BCPZ-R5 Analog Devices Inc. |
介面 - 數據機 - IC 與模組, IC HART MODEM 24LFCSP | RFQ |
| AD5700-1ACPZ-RL7 Analog Devices Inc. |
介面 - 數據機 - IC 與模組, IC HART MODEM LP INT OSC 24LFCSP | RFQ |
| ADG5412FBCPZ-RL7 Analog Devices Inc. |
介面 - 類比開關、多工器、解多工器, IC SWITCH QUAD SPST BID 16LFCSP | RFQ |
| ADG5412FBRUZ Analog Devices Inc. |
介面 - 類比開關、多工器、解多工器, IC SWITCH QUAD SPST BID 16TSSOP | RFQ |
| ADSP-BF707BBCZ-4 Analog Devices Inc. |
嵌入式 - 數位訊號處理器 (DSP), IC DSP LP 1024KB L2SR 184BGA | RFQ |
| ADSP-BF706BCPZ-4 Analog Devices Inc. |
嵌入式 - 數位訊號處理器 (DSP), IC DSP LP 1024KB L2SR 88LFCSP | RFQ |
| AD9106BCPZRL7 Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 12BIT SPI/SRL 32LFCSP | RFQ |
| AD9705BCPZRL7 Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC TX 10BIT 175MSPS 32-LFCSP | RFQ |
| AD5681RBCPZ-1RL7 Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 12BIT SPI 8LFCSP | RFQ |
| AD5420AREZ-REEL7 Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 16BIT 1CH SER 24TSSOP | RFQ |
| AD9705BCPZ Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC TX 10BIT 175MSPS 32-LFCSP | RFQ |
| AD5681RBRMZ Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 12BIT SPI 10-MSOP | RFQ |
| AD9106BCPZ Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 12BIT SPI/SRL 32-LFCSP | RFQ |
| AD5420AREZ Analog Devices Inc. |
資料採集 - 數位類比轉換器 (DAC), IC DAC 16BIT 1CH SER 24TSSOP | RFQ |
| AD9629BCPZ-80 Analog Devices Inc. |
資料採集 - 類比數位轉換器 (ADC), IC ADC 12BIT 80MSPS 32LFCSP | RFQ |
| AD9629BCPZ-40 Analog Devices Inc. |
資料採集 - 類比數位轉換器 (ADC), IC ADC 12BIT 40MSPS 32LFCSP | RFQ |
| AD9670BBCZ Analog Devices Inc. |
資料採集 - 類比前端 (AFE), IC AFE 14BIT 8CH W/DIG DEMOD BGA | RFQ |
| ADT7320UCPZ-R2 Analog Devices Inc. |
Temperature Sensors, Transducers, SENSOR TEMPERATURE SPI 16LFCSP | RFQ |
| ADT7320UCPZ-RL7 Analog Devices Inc. |
Temperature Sensors, Transducers, SENSOR TEMPERATURE SPI 16LFCSP | RFQ |
| ADF7242BCPZ-RL Analog Devices Inc. |
RF 收發器 IC, IC RF TXRX+MCU 802.15.4 32-WFQFN | RFQ |
| ADF7023-JBCPZ Analog Devices Inc. |
RF 收發器 IC, IC RF TXRX+MCU ISM<1GHZ 32-WFQFN | RFQ |
| ADF7023BCPZ Analog Devices Inc. |
RF 收發器 IC, IC RF TXRX+MCU ISM<1GHZ 32-WFQFN | RFQ |
| ADF7242BCPZ Analog Devices Inc. |
RF 收發器 IC, IC RF TXRX+MCU 802.15.4 32-WFQFN | RFQ |
| ADM2582EBRWZ-REEL7 Analog Devices Inc. |
數位隔離器, DGTL ISO RS422/RS485 20SOIC | RFQ |
| ADM2582EBRWZ Analog Devices Inc. |
數位隔離器, DGTL ISO RS422/RS485 20SOIC | RFQ |
| ADM2587EBRWZ Analog Devices Inc. |
數位隔離器, DGTL ISO RS422/RS485 20SOIC | RFQ |
| ADM2587EBRWZ-REEL7 Analog Devices Inc. |
數位隔離器, DGTL ISO RS422/RS485 20SOIC | RFQ |
Traction inverters are the main battery drain components in electric vehicles (EVs), with power levels up to 150kW or higher. The efficiency and performance of traction inverter directly affect the driving range of electric vehicle after a single charge. Therefore, in order to build the next generation of traction inverter systems, silicon carbide (SiC) field effect transistor (FET) is widely used in the industry to achieve higher reliability, efficiency and power density.
Do you know the 8 application circuits of operational amplifiers?
This technical presentation requires an understanding of how to configure an operational amplifier in a typical gain control circuit. The applications of linear and nonlinear digital potentiometers are discussed. This article gives an overview of the basic techniques required to convert audio and other potentiometer/op amp applications from conventional mechanical potentiometers to solid state potentiometers
The current in an electronic circuit usually has to be limited. In USB ports, for example, excessive current must be prevented to provide reliable protection for the circuit. Also in the power bank, the battery must be prevented from discharging. Too high discharge current results in too large voltage drop of the battery and insufficient supply voltage of downstream devices
Using advanced real-time control technologies such as motor control circuits with higher power density, higher integration and more efficient systems, better acoustic performance of the system can be achieved
Brushless direct current (BLDC) motors have been widely used in household appliances, industrial equipment and automobiles. While brushless DC motors offer a more reliable and maintainable alternative to traditional brushless motors, they require more sophisticated electronics to drive them
How to achieve precise motion control in industrial actuators
The NCP51820 is a 650 V, high-speed, half-bridge driver capable of driving gallium nitride (" GaN ") power switches at dV/dt rates up to 200 V/ns. The full performance advantages of high voltage, high frequency and fast dV/dt edge rate switches can only be realized if the printed circuit board (PCB) can be properly designed to support this power switch. This paper will briefly introduce NCP51820 and the key points of PCB design of high performance GaN half bridge grid driver circuit using NCP51820
