PARTICLE SIZE ANALYSIS
PTI has many years experience in particle size analysis. We offer quick turn around, typical lead time is one to two days, and very competitive pricing. Download our Particle Size Analysis Request Form and submit either via email or include with your sample(s). Please see below for the various particle size analysis techniques we have available to analyze your material.
PARTICLE SIZE ANALYSIS UTILIZING A COULTER MULTISIZER III
The Coulter Principle, also known as ESZ (Electrical Sensing Zone Method), the 3 Coulter Counter provides number, volume, mass and surface area size distributions in one measurement, with an overall sizing range of 0.4 to 1,200 microns (practical limits for most industrial powders are from 0.06 to 200 microns). Its response is unaffected by particle color, shape, composition or refractive index.
Particles suspended in a weak electrolyte solution are drawn through a small aperture, separating two electrodes between which an electric current flows. The voltage applied across the aperture creates a “sensing zone”. As particles pass through the aperture (or “sensing zone”), they displace their own volume of electrolyte, momentarily increasing the impedance of the aperture.
This change in impedance produces a pulse that is digitally processed in real time. The Coulter Principle states that the pulse is directly proportional to the tri-dimensional volume of the particle that produced it. Analyzing these pulses enables a size distribution to be acquired and displayed in volume (µm3 or fL) and diameter (µm). In addition, a metering device is used to draw a known volume of the particle suspension through the aperture; a count of the number of pulses can then yield the concentration of particles in the sample.
- High density materials requiring an increased viscosity electrolyte are subject to an additional fee per sample.
- Conductive materials such as carbon, metal powder, etc. are subject to an additional fee per sample.
- Materials that are soluble in water and require special electrolytes are subject to an additional fee per sample.
- We will need approximately one gram or more of sample to perform a particle size analysis.
PARTICLE SIZE ANALYSIS UTILIZING A SIEVE SHAKER
Particle size analysis tests may be performed using U.S. Standard Size designated test sieves Number 8 through Number 400. This corresponds to particle size diameters of 2.36 mm (Number 8) through 38 micron (Number 400).
One of two types of sieve shakers may be employed:
- Gilson SS-15 – for analysis using U.S. Sieves #200 and larger.
- W.S. Tyler Ro-Tap – for analysis using U.S. Sieves below #200.
- Materials that retain static surface charges may be difficult to analyze with repeatability.
- We will need a minimum of fifty grams to perform a particle size analysis on the Ro-Tap or Gilson sieve shaker.
PARTICLE SIZE ANALYSIS UTILIZING A MICROTRAC MODEL S3500 LASER DIFFRACTION
Particle size analysis measuring capabilities ranging from 0.24 to 2800 micron using Leeds & Northrup Microtrac Model S3500 Particle Size Analyzer.
- Standard resolution output may be expressed in % passing or % retained and includes differential and cumulative graphical data.
- Materials that are soluble in water or require special suspension fluids are subject to an additional fee per sample.
- We will need approximately one gram or more of sample to perform a particle size analysis.
Relevant FAQ
We provide particle size analysis using various techniques but we do not perform particle counting. Please click on the following link for information regarding particle-counting services: Interbasic Resources, Inc www.ibr-usa.com.
We receive many questions regarding ISO, SAE and AC Test Dusts. For answers to most of these questions please read the “Test Dust History”
Jet milling: Particle sizes attained from jet milling are as low as a 4-micron median to as high as a 45-micron median. Jet milling is best suited for distributions ranging from 0-150 microns.
Hammer milling: Best suited for coarser distributions ranging from as low as ~20 microns up to ~ 2000 microns.
Vibratory screening: Screen sizes from 38 – 4800 microns are available.
Air classification: Particle size distributions as tight as nominal 0-3 microns and as broad as nominal 0-45 microns can be achieved.
Jaw crushing: Primarily used as a pre-crushing step for material that is too large to feed into a secondary mill, such as a jet mill or hammer mill. Our jaw crusher can reduce material as large as 5” x 7” down to minus 10 mesh in one pass.
