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See Through the Muddy Flow: How Bettersize’s New US Patent Solves Window Contamination in In-Situ Sediment Monitoring

2026-07-17News

US Patent · In-Situ Sediment Monitoring

See Through the Muddy Flow: How Bettersize’s New US Patent Solves Window Contamination in In-Situ Sediment Monitoring

Discover how the DeepSizer 300 uses a patented differential optical path method to mathematically remove window-fouling interference and maintain accurate particle size distribution and solid content measurements in complex two-phase flows.

KEY TAKEAWAY

Instead of relying on frequent manual cleaning or fixed background estimates, the DeepSizer 300 compares signals from two optical path lengths and subtracts the shared contamination component, leaving the true sediment signal.

1. Real-World Challenge of Two-Phase Flow Monitoring

In hydrological monitoring, tracking the particle size gradation and solid content of sediment in rivers, oceans, and ports is critical for soil erosion prevention, dam maintenance, and waterway regulation. These environments represent complex liquid-solid two-phase flows.

Continuous monitoring requires instruments to remain submerged in non-pure media for extended periods. As a result, the measurement window inevitably becomes contaminated, affecting both the optical background and the accuracy of the final results.

To address this limitation, the United States Patent and Trademark Office granted US Patent 12,680,936 B2 to Dandong Bettersize Instruments Ltd. on July 14, 2026. The patent introduces a differential optical path methodology designed specifically to compensate for window contamination in online monitoring systems.

2. Core Problem: The “Dirty Window” Effect

Standard laser particle size analyzers face two primary limitations when deployed for in-situ sedimentation monitoring:

Absence of Pure Backgrounds

Active rivers and industrial flows are not pure-medium environments. The instrument cannot capture a clean background signal in real time and must rely on a fixed background estimate, which can interfere with the actual sediment scattering signal.

Lens Fouling

Long-term immersion causes contamination on the measurement window. This fouling introduces errors into both extinction and scattering signals, compromising particle size gradation and solid content calculations.

3. The Solution: Differential Optical Path Measurement

To conceptually understand the patented methodology, consider the challenge of looking through a consistently dirty glass window. By taking measurements from two different distances through that exact same dirty glass, the optical system can mathematically separate the fouling on the glass from the objects in the water.

In application, the DeepSizer 300, a proud Bettersize product, using US Patent 12,680,936 B2, dynamically changes the width of the measurement area. The analyzer collects scattered light intensity and extinction values at two distinct lengths: a long optical path (L₁) and a short optical path (L₂).

Long Optical Path

Short Optical Path

3.1 How Does the DeepSizer 300 Compensate for Window Contamination?

Instead of attempting to physically clean the window or relying on fixed estimates, the DeepSizer 300 employs signal processing. The scattered signal from the short optical path is subtracted from the scattered signal of the long optical path on each detector.

Because the window contamination is present in the background of both signals, it is completely mathematically subtracted. The remaining value represents the true scattered signal of the sediment in the two-phase flow, retaining pure particle size distribution information.

Signal Isolation Process

Long-path signal − Short-path signal = True sediment scattering signal

3.2 Mathematical Isolation of Solid Content

For accurate solid content calculation, the DeepSizer 300 processes the extinction values logarithmically. The difference between the logarithms isolates the actual solid particles from the contaminated window interface:

ln(I₁/I₀) − ln(I₂/I₀) = −[3C_vK_ext / 2D] × (L₁ − L₂)

By defining the volume concentration (C_v) and using the surface area mean diameter (D) inverted from Mie scattering data, the solid content (H) can be calculated using particle density (ρ):

H = C_v × ρ = −{[ln(I₁/I₀) − ln(I₂/I₀)] × 2D / [3K_ext(L₁ − L₂)]} × ρ

4. Lower Operational Expenditure and Unbiased Data Integrity

Translating this patented methodology into physical hardware, such as the DeepSizer 300, solves practical problems in in-situ sedimentation monitoring. The DeepSizer 300 directly impacts how field teams operate and collect data across diverse environments.

01 · Expanding Application Scenarios and Water Conditions:

Because the technology mathematically isolates the true particle scattering signal from background interference, the instrument is not restricted to environments with stable, predictable turbidity. This design allows the DeepSizer 300 to operate across a wider variety of fluctuating conditions, including monitoring sediment in rivers, oceans, and ports.

02 · Elimination of Constant Manual Retrieval:

Traditional submersible sensors need frequent, labor-intensive retrieval from the waterbody for maintainence. By mathematically negating this fouling, the differential path method drastically reduces maintenance intervals, saving field labor costs and operational time.

03 · Preventing Spatial Sampling Bias:

Manual water sampling forces personnel to collect sample from where it is physically accessible—often too close to the riverbank or surface. This introduces heavy data bias that fails to reflect the true sediment dynamics of the main channel. The DeepSizer 300 remains continuously deployed in the representative flow zone, delivering accurate, unbiased in-situ data.

04 · Maintaining Signal Accuracy Without Recalibration:

Over time, window fouling in liquid-solid two-phase flows creates optical noise that obscures actual particle data. The patented differential method isolates a pure scattered light intensity signal by mathematically subtracting this shared error variable. As a result, the DeepSizer 300 can continuously calculate accurate particle size distribution and solid content without needing periodic zero-baseline recalibrations in a pure medium.

5. Bettersize’s Technological Authority

The granting of US Patent 12,680,936 B2 transitions in-situ sedimentation monitoring from a hardware maintenance vulnerability into a stable, algorithmically validated process.

By mathematically eliminating the primary source of online measurement drift, Bettersize Instruments and the DeepSizer 300 establish a new baseline for data reliability in complex, two-phase flow environments.

Explore Reliable In-Situ Sediment Monitoring

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