The ultrasonic flow meter portable is a non-contact instrument primarily used for measuring the flow of fluids that are difficult to access or observe, especially in large-diameter pipelines. In recent years, ultrasonic flow meters have become increasingly popular due to their ability to measure flow without direct contact. This feature effectively addresses challenges in measuring liquid or gas flow under harsh conditions such as radioactive, highly corrosive or viscous fluids, clogging, low-pressure loss requirements, presence of bubbles or particles. As a result, ultrasonic flow meters are widely used in fields like pharmaceuticals, petrochemicals, and environmental protection.
Features of Ultrasonic Flow Meter Portable
Compared with traditional mechanical and electromagnetic flow meters, ultrasonic flow meters offer several key advantages:
- Non-contact measurement: They can measure flow from outside the pipe without causing pressure loss or altering the flow state. No modifications to the existing piping are needed.
- Linear signal output: The output signal has a linear relationship with the flow rate of the fluid being measured.
- Insensitive to viscosity and conductivity: Measurement is not affected by fluid viscosity or conductivity, making it suitable for non-conductive liquids or gases.
- Cost-effective for large-diameter flow measurement: The measurement cost is largely independent of pipe size, unlike other flow meters whose cost increases significantly with diameter.
- Well-suited for harsh conditions: Since there is no need for contact with the fluid, the device offers convenience and benefits in difficult environments.
However, there are also some limitations. For example, clamp-on ultrasonic flow meters are easy to maintain and replace without stopping the flow or affecting production, but because the measurement is done outside the pipe with fewer acoustic paths, the accuracy is lower than that of in-line ultrasonic flow meters. On the other hand, in-line ultrasonic flow meters may be more complex to maintain or replace, but they can achieve higher accuracy due to having more channels (three, four, or more). Additionally, installation requires a long section of straight pipe before and after the flow meter, which can increase costs and complexity.
Selection Considerations for Ultrasonic Flow Meter Portable
Choosing the right ultrasonic flow meter portable can be complex. Important factors to consider include the type of medium being measured, instrument performance and specifications, transducer type and function, number of acoustic paths, and requirements for upstream and downstream straight pipe lengths. Key considerations include:
- Understand the physical characteristics and on-site conditions of the measured object.
- The signal processing unit must be suitable for outdoor or hazardous environments, with appropriate explosion-proof and protection ratings.
- A certain length of straight pipe is required upstream and downstream of the transducer to ensure a stable flow profile. Typically, more than 10D upstream and 5D downstream are required, and no valves or pumps should be installed within 30D upstream.
- When installing transducers on inclined or horizontal pipes, avoid placing them at the top or bottom to prevent gas or impurities from entering the acoustic path.
- The ultrasonic transmission path should pass through the center of the pipe.
- Different transducers are used for different media: for gas, the frequency is typically 100–300 kHz, while for liquids, it’s usually 1–5 MHz.
Applications of Ultrasonic Flow Meter Portable in Chemical Measurement
Using transit-time ultrasonic flow meters for refined oil measurement
Ultrasonic flow meter portable can use multiple acoustic paths for more accurate measurements. They can monitor operational status through alarms and diagnostic software, auto-adjust gain on each path, and measure flow distribution across channels. By calculating the speed of sound on the primary channel, they can correct for swirl and asymmetric flow. When the fluid’s density and viscosity change, the speed of sound measurement can be used to estimate these properties, allowing ultrasonic flow meters to replace density meters and solve challenges in multi-product pipeline handling.
On-site calibration with standard volume tubes
Ultrasonic flow meter portable can be calibrated using a bidirectional standard volume tube, which is a mechanical volumetric device. It typically has two (or four) detection switches at the inlet and outlet of a U-shaped standard tube, along with a displacer (ball or piston). When the displacer passes the first switch, it enters the standard volume section. When it triggers the second switch, it exits. The ultrasonic flow meter’s pulse output has a known time delay relative to the actual flow velocity. However, due to complex fluid turbulence and non-axial components, multiple disturbances may exist. By measuring time differences in forward and reverse directions through one or more acoustic paths, the flow velocity can be accurately derived.
As a non-contact instrument, the ultrasonic flow meter portable can measure the flow of large-diameter media and those that are difficult to observe or reach. It delivers high accuracy and is unaffected by the physical properties of the medium. It is an effective tool for measuring non-conductive, corrosive, flammable, explosive, or radioactive fluids, making it highly suitable for the petrochemical industry and offering broad application prospects.
