Particle Size and Zeta Potential Analyser---NKT-N9

Product Overview

The NKT-N9 series nanoparticle size analyser is an analytical instrument specifically designed to characterise the size and distribution of nanoparticles. Based on the principles of dynamic light scattering (DLS) and photon correlation spectroscopy (PCS), the instrument utilises a laser to illuminate nanoparticles uniformly dispersed in the sample cell. A fibre optic probe detects the dynamic scattered light at a 90° angle, capturing the time-dependent fluctuations in intensity caused by the Brownian motion of the particles, which is then transmitted to a photomultiplier tube (PMT). which converts the light signal into discrete pulse signals. These are then processed by a digital correlator to generate an autocorrelation curve for the sample. By combining this with mathematical methods, the diffusion coefficient of the particles is determined, and finally, the particle size and distribution of the sample are calculated using the Stokes-Einstein equation.

Scope of Application

The NKT-N9 laser particle size analyser is widely used across various sectors—including new materials, pharmaceuticals, bioengineering, life sciences, chemical engineering, coatings and food safety—for the particle size characterisation of organic or inorganic nanoemulsions, powders, polymers, micelles, viral antibodies and proteins, as well as for analysing the dispersion and stability of sample systems.

Technical Explanation

1 All-fibre test setup, delivering high sensitivity

The test optical path, constructed using a high-performance, low-noise fibre-coupled semiconductor laser and a fully fibre-based dynamic light scattering detection system, employs a low-dark-current, high-sensitivity Hamamatsu photomultiplier tube (PMT) as the photodetector. This endows the entire test system with exceptional sensitivity and signal-to-noise ratio, laying the foundation for testing accuracy and high resolution.

1 High-speed digital correlator, delivering high resolution

A proprietary high-speed digital correlator serves as the core component for signal processing, enabling high-speed, real-time acquisition of dynamic scattered light intensity and performing autocorrelation calculations. It possesses the ability to resolve 6 ns signals, offers data processing speeds in the hundreds of megabits per second, and features a linear dynamic range exceeding 10¹¹ counts, ensuring the integrity of autocorrelation curves for particles of varying sizes across the entire measurement range.

1 Full-range calibration and verification to ensure testing accuracy

Calibration and verification are performed across the entire measurement range using multiple national particle size reference materials, with testing accuracy errors consistently below 1% (exceeding the requirements of the national standard GB/T 29022-2021/ISO 22412:2017).

1 High-precision temperature control

The semiconductor laser, equipped with automatic temperature control technology, ensures stable and reliable laser output. The high-precision temperature control system maintains a constant temperature for the sample in the sample cell throughout the entire testing process, thereby avoiding measurement errors caused by changes in medium viscosity and particle Brownian motion velocity due to temperature fluctuations, thus guaranteeing the reliability and stability of the test results.