The Electrical Sensing Zone technique aka….

coulter counter techniqueThe Electrical Sensing Zone technique (also known as the Coulter Counter) has been used as a method of particle size measurement since it’s development in the 1950’s. Originally developed for counting blood cells, it was quickly realised that the ‘Coulter Counter’ could be of great help in particle size analysis of almost any powder, suspension or emulsion, providing rapid, reliable and reproducible results.

Since the Coulter Counter measures the particle volume ( one of the few techniques to measure an actual particle parameter rather than an effect of the particle on light or settling rate) it produces a particle size distribution by volume(weight), but it also has the advantage that it measures the particles individually (particle counting) and provides a particle count or concentration measurement.

One of the highest resolution techniques available it can measure and show extremely small changes in particle size.  With a number of ISO and ASTM standards for different applications,  the Coulter Counter offers an established technique for particle characterisation.

A brief guide to particle counters

A particle counter is used to count and size particles directly, rather than other methods where numbers, volumes and sizes are estimated. Continue reading A brief guide to particle counters

But What Is a Coulter Counter?

What is a Coulter Counter

For the last couple of years I have been writing posts on Coulter Counter applications, developments and history, some of which have been quite detailed, but this month I thought I would pause and give a simple summary for those who are new to the subject. Continue reading But What Is a Coulter Counter?

Benefits of the Multisizer 4e Coulter Counter

In my July post I summarised the features and capabilities of the new Multisizer 4e Coulter Counter from Beckman Coulter. There is never enough space in a short post to do justice to such a product advance, so I thought I would return to it and say something about what it will mean to those for whom particle characterisation is a vital task. Continue reading Benefits of the Multisizer 4e Coulter Counter

Moving the Lab Forward

I’ve just been watching a short video on the Beckman Coulter website. Entitled ‘Lab Forward’, it’s one of several videos that really help to give a flavour of the company and its philosophy. Continue reading Moving the Lab Forward

Multisizer 4e


A new member has been added to the Coulter Counter family, from Beckman Coulter, in the shape of the Multisizer 4e. With this instrument, particles and cells as small as 0.2 microns can be accurately counted and measured. Continue reading Multisizer 4e

Beckman Coulter’s Portfolio

Flow cytometry – Beckman Coulter

The story of the company founded by Dr Arnold O Beckman is one of non-stop innovation and expansion to ensure that scientists in the biomedical, life science and related fields have access to a full range of high-quality analytical instruments. As part of that growth, it has made a number of vital acquisitions – including that of the Coulter Corporation in 1997, which resulted in the new name Beckman Coulter. Continue reading Beckman Coulter’s Portfolio

Investigating Sea Water

Investigating sea waterToday my research on the Beckman Coulter website has turned up some useful application notes on using a Coulter Counter to count and size particles and cells in sea water. You can find and download the document yourself by visiting the site, clicking on the appropriate product area and then choosing ‘Literature’ in the right-hand column. Continue reading Investigating Sea Water


Haematology - glb_bci_153873Haematology – the branch of medicine concerned with study and treatment of the blood – was the very reason for the Coulter Counter’s invention and it continues to be at the heart (forgive the pun) of Beckman Coulter’s activities today. Continue reading Haematology

Beckman Coulter

Dr Arnold O Beckman

Dr Arnold O Beckman

If you’re a user of Coulter Counters and the Coulter Principle, you will undoubtedly know something of their inventor, Wallace H Coulter. His name lives on through his many achievements, and in the name of the company that continues to perfect and manufacture Coulter Counters today: Beckman Coulter. I would now like to tell you a little about that company and its founder, Dr Arnold O Beckman. Continue reading Beckman Coulter