Compact Nanoparticle Size & Zeta Potential Analyzer

The NKT‑N9 series nanoparticle size analyzers are specifically designed for the characterization of nanoparticle size and size distribution. Based on the principles of Dynamic Light Scattering (DLS) and Photon Correlation Spectroscopy (PCS) technology, the instrument uses a laser to illuminate nanoparticles uniformly dispersed in a sample cell.

The detection fiber receives, at a 90° angle, the dynamic scattered light whose intensity fluctuates over time due to the Brownian motion of the sample particles. This light is transmitted to a photomultiplier tube (PMT), which converts the optical signals into discrete pulse signals. A digital correlator then performs autocorrelation calculations to obtain the autocorrelation curve of the sample. Combined with mathematical methods, the diffusion coefficient of the particles is derived, and finally the particle size and size distribution are calculated according to the Stokes‑Einstein equation.

The NKT‑N9 laser particle size analyzer is widely used for particle size characterization as well as dispersion stability and system stability analysis of organic or inorganic nano‑emulsions, powders, polymers, micelles, virus antibodies, proteins, and other samples in fields such as:

• New materials
• Medicinal products
• Bioengineering
• Life sciences
• Chemical engineering
• Coatings
• Food safety

The test optical path, constructed with a high‑performance, low‑noise fiber‑coupled semiconductor laser and an all‑fiber dynamic scattered light receiving system, uses a low dark count, high‑sensitivity HAMAMASTU photomultiplier tube (PMT) as the photodetector. This gives the entire test system extremely high sensitivity and signal‑to‑noise ratio, laying the foundation for test accuracy and high resolution.

The independently developed high‑speed digital correlator is used as the core device for signal processing. It acquires dynamic scattered light intensity in real time at high speed and performs autocorrelation calculations. It features a signal resolution capability of 6 ns, a data processing speed of hundreds of megahertz, and a linear dynamic range greater than 10¹¹, ensuring the integrity of autocorrelation curves for particles of different sizes across the full measurement range.

Multiple national particle size reference materials are used for calibration and validation across the full measurement range, with test accuracy errors all below 1 %.

The semiconductor laser, equipped with automatic temperature control technology, ensures stable and reliable laser output. The high‑precision temperature control system keeps the tested sample in the sample cell at a constant temperature throughout the measurement process, avoiding test deviations caused by changes in medium viscosity and particle Brownian motion velocity due to temperature variations, thereby ensuring reliable and stable test results.

Using dual‑wavelength (λ1 = 520 nm, λ2 = 405 nm) fiber‑coupled semiconductor lasers as the light source overcomes the limitation that a single‑wavelength laser cannot test light‑absorbing samples, enabling effective particle size testing for full‑color‑range samples. One‑click switching between the two wavelengths makes the instrument applicable to a wider range of samples.