A multi-laser BI-200SM goniometer system for exacting light scattering measurements

Testa Analytical Solutions e.K announce the launch of an upgrade kit for its BI-200SM light scattering goniometer system providing access to multiple laser Static Light Scattering (SLS) and Dynamic Light Scattering (DLS) techniques.

Traditionally, selection of the most appropriate wavelength for SLS or DLS applications has necessitated replacement of one laser with a different one, a time-consuming operation requiring precision re-alignment work. Alternatively, users could elect to employ a single, very costly multi-wavelength Ar-Ion laser in their light scattering goniometer system.

The new multiple laser upgrade kit allows easy setup up of two or three lasers sharing the same zero alignment on a BI-200SM light scattering goniometer. Each installed laser can be selected simply by flipping a mirror assembly. This kit hugely extends the range of applications that can be investigated using a BI-200SM light scattering goniometer. Now users have the option of quickly selecting the most appropriate wavelength and power for their research employing up to 3 affordable diode lasers sharing a common alignment.

A versatile multi laser combination might employ a red laser operating at 640nm and a green laser at 535 nm. This multi-laser BI-200SM system would be perfect for investigating both “normal” samples and also samples which fluoresce necessitating light scattering must be performed at a different wavelength. A further advantage of a multi laser BI-200SM is that it offers the possibility to select shorter wavelength, like 488 nm. This allows the system to be used to determine light scattering of very small particles, very low molecular weight polymers and take advantage of the higher refractive index increment at that lower wavelength. Also, determination of light scattering at different wavelengths shows promise for use in highly accurate structural investigations usually only accessible with far more challenging techniques. The wide range of multi wavelength possibilities opened up by the multi laser upgrade kit is ably supported by the growing range of reliable and affordable laser diode systems"

Carlo Dessy, Managing Director, TESTA Analytical

The Bl-200SM goniometer system is a precision research grade instrument designed for exacting light scattering measurements. Based on a special turntable with precision ball bearings and stepping motor, the Bl-200SM's modular, automated design and quality construction guarantee precise measurements due to the wobble-free movement of the detector. As you would expect from a research grade system the BI-

200SM can measure light scattering over a wide angular range (8° to 155° with 25 mm cells) and offers fine adjustment of measurement angles to 0.01° directly using a large, fine-control knob or PC-driven Motor control. Fine-screw vertical adjustment makes center of rotation measurement easier when aligning cells. Precise repeatable data is ensured by automated heating and cooling of the sample cell using and standard external recirculating system. Field proven in hundreds of labs around the world the BI-200SM light scattering goniometer system is ideal for even the most demanding macromolecular studies and submicron particle sizing applications.