New Count Rate Meter: light scattering from buffer or background

Why a count rate meter? Occasionally, you want to simply check the overall light scattering intensity of a sample. Well, the new count rate meter in the Zetasizer ZS Xplorer software allows you to do just that. As a result, find the count rate (kcps) of a buffer for MADLS / Particle Concentration experiments or confirm a clean cuvette.

 

What is the count rate meter?

The Zetasizer Advance series is a powerful tool for size and zeta measurements. But sometimes you don’t need a complete size or zeta record, you only want to see the intensity. The count rate meter is a utility to show the mean count rate and standard deviation of the sample in the system. It shows how many photons per second arrive at the detector. These data are averaged (over the duration) and provide a mean and a standard deviation.

 

How to access the count rate meter

This new feature available in version 2.30 appears as a launch-able button in the lower right corner of the software. Simply download v2.30 and install, then start the ZS Xplorer software. The button comes in two flavors: available in green and not available in grey.

If your instrument is connected to the software, the count rate meter button should be green, unless you are already measuring. You can launch it from the main software interface screen.

Why use it?

You can now measure the mean count rate and standard deviation as stand-alone, without doing a full-size measurement. Correspondingly, by this method, you can

• find the intensity of a scattering standard, like toluene
• determine the background of a solvent or buffer for a MADLS or Particle Concentration experiment – the count rate can be copied to the clipboard to paste into your method solvent count rate parameter
• check your sample preparation, to confirm cuvette and buffer cleanliness

This new feature provides count rate info even in cases where a size measurement may not be possible due to low sample count rates. So it’s a flexible little utility for a wide range of situations. In order to make use of it, simply select the cell (or cuvette type), the attenuator position, and the duration. Mouse-over popups and the help file have more details on the choices.

In order to find your help file, go to Home (upper left corner) and locate the help bookmark.

 

Previously

• How to create an account on the webstore
• Help for my instrument – one step away
• What is included with a new instrument? Packing list for the Zetasizer
• Standard deviation – how to calculate it with Excel

Have any questions? Please email me at ulf.nobbmann@malvern.com – thanks! 

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