Microtrac’s NANOTRAC Wave II / Zeta is a highly flexible Dynamic Light Scattering (DLS) analyzer which provides information on particle size, zeta potential, concentration, and molecular weight. It allows faster measurements with reliable technology, higher precision, and better accuracy. All of this combined into a compact DLS analyzer with a revolutionary fixed optical probe.
With the unique and flexible probe design and the use of the Laser Amplified Detection method in the NANOTRAC Wave II / Zeta, the user is able to choose from a wide array of measurement cells that satisfy the needs of any application. This design also allows measurements of samples over a wide concentration range, monomodal or multimodal samples, all without prior knowledge of the particle size distribution. This is made possible through the use of the Frequency Power Spectrum (FPS) method instead of classical Photon Correlation Spectroscopy (PCS).
All NANOTRAC WAVE series analyzers use the same revolutionary probe technology for DLS measurements. Utilizing our Laser Amplified Detection method, repeatable and stable particle size measurements for all types of materials are provided.
The NANOTRAC WAVE II series can also calculate the sample concentration through the use of the power spectrum and the resulting loading index. Depending on the distribution calculation, concentration will be displayed in appropriate units such as cm3/ml or N/ml. It is also possible to calculate the molecular weight by either the hydrodynamic radius or a Debye plot.
The NANOTRAC WAVE II particle analyzer has multiple reusable samples cells in different sizes. There is a standard and micro volume Teflon cell for a wide range of materials. For more difficult to clean samples, there is a standard volume stainless steel cell, as well as a large volume stainless steel cell.
The NANOTRAC WAVE II Zeta particle analyzer has a special reusable zeta cell with an electrode for running zeta potential measurements. Sample cells listed for the Wave II are also compatible with the zeta model.
| Method | Backscattered laser-amplified scattering reference method |
| Calculation model | FFT power spectrum |
| Measurement angle | 180? |
| Measuring range | 0.3 nm - 10 ?m |
| Sample cell | Various sample cell options |
| Zeta potential analysis | yes |
| Zeta measurement range (potential) | -200 mV - +200 mV |
| Zeta measurement range (size) | 10 nm - 20 ?m |
| Electrophoretic mobility | 0 - 15 (?m/s) / (V/cm) |
| Conductivity measurement | yes |
| Conductivity range | 0 - 10 mS / cm |
| Molecular weight measurement | yes |
| Molecular weight range | <300 Da -> 20 x 10^6 Da |
| Temperature range | +4?C - +90?C |
| Temperature accuracy | ? 0.1?C |
| Temperature control | yes |
| Temperature control range | +4?C - +90?C |
| Titration | yes |
| Reproducibility (size) | =< 1% |
| Reproducibility (zeta) | + / - 3% |
| Sample volume size measurement | 50 ?l - 3 ml |
| Sample volume zeta measurement | 150 ?l - 2 ml |
| Concentration measurement | yes |
| Sample concentration | up to 40 % (sample dependent) |
| Carrier fluids | Water, polar and unpolar organic solvents, acid and base |
| Laser | 780 nm, 3 mW; 2 laser diodes with zeta |
| Humidity | 90 % non-condensing |
| Dimensions (W x H x D) | 355 x 381 x 330 mm |
The optical bench of the nanoparticle size analyzer NANOTRAC WAVE II is a probe containing an optical fiber coupled with a Y splitter. Laser light is focused on a volume of sample at the interface of the probe window and the dispersion. The high reflectivity sapphire window reflects a portion of the laser beam back to a photodiode detector. The laser light also penetrates the dispersion and the particle’s scattered light reflects at 180 degrees back to the same detector.
The scattered light from the sample has a low optical signal relative to the reflected laser beam. The reflected laser beam mixes with the scattered light from the sample, adding the high amplitude of the laser beam to the low amplitude of the raw scatter signal. This Laser Amplified Detection method provides up to 106 of times the signal to noise ratio of other DLS methods like Photon Correlation Spectroscopy (PCS) and NanoTracking (NT).
A Fast Fourier Transform (FFT) of the Laser Amplified Detection signal results in a linear frequency power spectrum which is then transformed into logarithmic space and deconvoluted to give the resulting particle size distribution. Combined with Laser Amplified Detection, this frequency power spectrum calculation provides robust calculation of all types of particle size distributions – narrow, broad, mono-modal or multi-modal – with no need for a priori information for algorithm fitting as it is for PCS.
The Laser Amplified Detection method used in Microtrac particle analyzers is unaffected by signal aberrations due to contaminants in the sample. Classical PCS instruments need to either filter the sample or create complicated measurement methods to eliminate these signal aberrations.
1. Detector | 2. Reflected laser beam & scattered light | 3. Sapphire window | 4. Y-beam splitter | 5. GRIN lens | 6. Sample | 7. Laser beam in optical
