FAQ

How much sample should I send?
There's no simple answer here, but we can give you some guidelines. If the material is dry (eg. Powders) then something in the range 1 - 10 gm is usually enough. The finer it is, the less we need. If sieving is required (sample includes particles > 2 mm) then at least 20 gm should be provided.

With waters we need enough particles to get a good result. The normal preferred sample size is 1 litre. If it is good dirty water, 0.5 litres or less may be enough. If it is clear water, but you can see a few specks floating around, then we may need up to 10 litres.

If in doubt, contact us to discuss your particular problem.

Where and how should I send it?
Samples can be sent by courier or by post, depending on urgency and the nature of the material. Ensure that the samples are packaged appropriately for safe carriage and properly identified. Include documentation with your contact details and any relevant information. We have an Analysis Request form which is downloadable from the contact page. Our addresses are also on this page.

How long does the analysis take?
We aim to have the results to you within 7 days of receiving your sample. Naturally we will respond more quickly if we can. If your need is especially urgent, contact us and we will see what we can do.

What sort of information do I get?

Our standard report (LLS) includes Sample Information, a Graph of the particle size distribution, Statistics (mean, etc.) and a Listing of the data. This is available in hard copy (by post), electronically or by fax. Contact us if you need particular results or a special format.

How accurate is the result?
We are talking about two things here: Accuracy and Reproducibility.

Accuracy is a thorny issue because of the problem of defining what Particle Size really means. Suffice to say that accuracy is 'engineered into' the LLS instruments. The measurement is based on the 'first principles' of the physics light scattering. There is no calibration of the instrument, though controls are used to check for correct operation.

Reproducibility is another matter, as there will always be variation in measurements. The specified reproducibility on repeat measurements for the Coulter LS230 instrument is <1%. Our quality monitoring confirms this. Sampling and sample preparation can be larger sources of error.

Do you have a Quality System?
Our measurement techniques are in accordance with ISO 13320-1.

What does it cost?
Have a look at our rate page. Contact us if you need to know more.

Do you keep the samples?
We normally keep solid samples for 3 months, in case reanalysis is required. Waters may be kept for 1 month though, in the case of dilute samples, it is common for the whole sample to be consumed during analysis.

My material is valuable. Can I have it back?
Maybe. LLS is essentially a 'destructive' technique as the dispersed sample is normally flushed to waste after analysis. PCS and sieving are non-destructive. Excess material can always be returned. Contact us for more information

My material is toxic or hazardous. Can you handle it?
That depends on just how toxic or hazardous. In any case, we need to know what we are handling and to be warned of any hazards. Please provide MSDS or equivalent information. Contact us for more information.

Where can I find out more about Particle Size Analysis?
A good comprehensive resource is the NIST Recommended Practice Guide “Particle Size Characterization" (NIST SP 960-1). This available free from www.nist.gov/msel/ceramics ; look under Products and Services / Recommended Practice Guides.