Characteristic dimension

1MHz ultrasonic sensor

2MHz ultrasonic sensor

The impact on water meter design

Wavelength and accuracy

Longer wavelength (about 1.5mm in water)

Short wavelength (about 0.75mm in water)

2MHz has higher accuracy and resolution. Shorter wavelengths can measure Time of Flight more accurately, especially sensitive to small flow rates and changes in flow velocity, which is beneficial for reducing the initial flow rate (high sensitivity)

Penetration and attenuation

Less attenuation, longer propagation distance of sound wave energy in water, and smaller loss

Significant attenuation makes it easier for sound wave energy to be absorbed and scattered by impurities and bubbles in water

1MHz is more suitable for working conditions with poor water quality (containing impurities and more bubbles). In large-diameter pipelines (such as DN100 and above), 1MHz can ensure that the signal reaches the opposite sensor smoothly, with higher reliability. 2MHz signal may experience severe attenuation in dirty water, leading to measurement failure

Beam angle

The beam angle is wide. The diffusion range of sound waves is larger

The beam angle is narrow. Sound wave energy is more concentrated and has better directionality

The 2MHz beam is more concentrated and less affected by flow field disturbances (eddies, asymmetric flows) inside the pipeline, which is beneficial for improving measurement stability. A 1MHz wide beam may introduce errors when the flow field is poor

Immunity to external noise

Strong anti-interference ability. Low frequency, far from the frequency range of common mechanical vibrations and flow noise

The anti-interference ability is slightly weaker. Higher frequencies may be more susceptible to interference from certain high-frequency noise

1MHz may perform more stably in noisy industrial environments. Careful circuit filtering is required to optimize the noise resistance of 2MHz

Cost and Process

Relatively low. The manufacturing process of ceramic chips and other materials is more mature

Relatively high. More precise process requirements for chip processing, matching layers, and acoustic sealing

A 1MHz sensor can help reduce the overall cost of the meter, which is crucial for the large civilian small caliber water meter market

Main application scenarios

Civil small-diameter water meters (DN15-DN50), large-diameter pipeline water meters (DN80 or above), and situations with complex water quality conditions

Industrial metrology with extremely high precision requirements, clean water media, small and medium-sized diameters (DN25-DN100), and optimized flow fields

The choice depends on the pipe diameter, water quality, and target accuracy level. There is no absolute good or bad, only the most suitable application