AgglomerateCohesive particles.
Aperture sizeDistance between two adjacent warp and weft wires, measured in the projected plane at the mid-positions (w).
ASTM E11= American Society for Testing and Materials; HAVER Test Sieves are also fabricated according to this standard (see International Test Sieve Comparison Table). 


BS 410= British Standards; HAVER Test Sieves are also fabricated according to this standard (see International Test Sieve Comparison Table).


CalibrationSee "Certification". For calibration thrice as many meshes are measured as for certification. 


Inspection of test sieves; the sieve medium is measured  in warp and weft direction with a calibrated measuring system at the customer's premises or in the laboratory of HAVER & BOECKER. The result is an inspection certificate 3.1 according to DIN EN 10 204.

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Test sample placed on a test sieve.

Coning and Quartering

Common manual method of sample preparation:

1. Pile the sample in a cone.

2. Spread the pile our in a circle with a uniform thickness.

3. Divide the circle into equal quarters.

4. Discard two opposite quarters and shovel them into a conival pile for a second division.

(„Test Sieving Handbook No. 53, 2003 Edition“ by W.S.TYLER)



= Computerized Particle Analysis: Technology of HAVER & BOECKER for photo-optical particle size and shape analysis of bulk materials.

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DIN ISOHAVER Test Sieves are also fabricated according to this standard; DIN ISO 3310-1: sieve medium = woven wire clothDIN ISO 3310-2: sieve medium = perforated plate(see International Test Sieve Comparison Table)
Dry sieving:Sieving of bulk material without using of water.
Dynamic image analysis:HAVER CPA: Particles are measured photo-optically in motion by passing the optics in a continuous mass flow.


Electroformed sheet:Electrochemically produced nickel foils have round or square holes in the micron range from 5 µm to 100 µm.
Excentric division:

The particles are accelerated outwards by means of a rotating cone in the rotating samle reducer and fall into the guide channels randomly.


Feret diameter (minimum):Smallest photo-optically detected particle dimension between two parallel tangents of the particle contour. When compared to sieve analysis results, it is a good approximation of the aperture size that the particle just passes through.  
Feret diameter (maximum):Largest photo-optically detected particle dimension. It is found by considering all possible connections between the pixel points of the projection surface and is not dependent on angle. 


Gold Test SievesHAVER Test Sieves / Quality "Gold" with tolerances 50% smaller than the tolerances as specified by ISO 3310-1.


HAVER REAL TIME:During the photo-optical particle analysis (HAVER CPA) the shadow projections of the particles are evaluated simultaneously to the measuring process in real time. 


Image analysissee "Dynamic image analysis"
International Test Sieve Comparison TableListing of all standards for the fabrication of test sieves with the corresponding aperture sizes / openings.


Light sourceLED light module in the HAVER CPA; the shadows of the free-falling particles are formed in the background of this light.
Line scan cameraDigital camera with one pixel line. The operating mode is comparable with a scanner.


Nominal sizeAperture size (woven wire cloth), size of hole (perforated plate)


Particle listOption in the Software HAVER CpaServ EXPERT. The table lists each single particle along with a scaled figure and diverse measurement and analysis values. Using the function of the particle list, a supplemental manual evaluation can follow. Also filter values or user-defined classifications of the shape class, for example, can be established as well.
Particle size

With HAVER CPA different size parameters are analysed: Feret diameter, Equivalent diameter, Length, Width (maximum), Martin diameter, Chord (maximum)

Sieve analysis: smallest aperture size in a sieve medium the particle passes through.

Particle size distributionResult of particle analysis: frequency distribution of particle sizes, displayed in bar or line diagram (distribution curve).
Perforated plateSieve medium; plate made from galvanized steel or stainless steel with regularly arranged round or square holes. 
Photo-optical particle analysisComputerized analysis of bulk materials concerning particle size and particle shape (dynamic image analysis, CPA).


SampleRepresentative part from a quantity of material or a product stream.
Sieve analysisSeparation and analysis of particle sizes of a sample of bulk material by means of one test sieve or a test sieve shaker and several test sieves. 
Sieve mediumWoven wire cloth or perforated plates in test sieves with identical, regularly arranged apertures.
Sieve panCollecting pan for the finest material of a sample at the bottom head of a sieve tower; available in all sieve diameters. 
Sieve setTower made from two or more assembled test sieves with increasing aperture size from bottom to top and a sieve pan. 
StandardHAVER & BOECKER is certified to ISO 9001 and is a leading member of the International Standards Committee for Test Sieves (ISO TC 24). HAVER Test Sieves are fabricated according to the valid standards: ISO 565, ISO 3310, ASTM E11, BS 410, NEN 2560, ISO 5223... The "International Test Sieve Comparison Table" gives a general idea.


WarpAll wires running lengthwise of the cloth as woven.
WeftAll wires running across the cloth as woven.
Wet sievingSieving with fluids.
Wire diameterDiameter of the wire in the woven cloth.
Woven wire clothProduced by HAVER & BOECKER Wire Weaving Division, made from wire with square aperture sizes from 20 micron up to 125 mm.


X-ToleranceTolerance for the single values of all measured aperture sizes (w), specified in standards. No aperture size that is measured in warp and weft direction shall exceed X.


Y ToleranceTolerance for the arithmetic mean value of the sum of all measured aperture sizes (w), measured separately in warp and weft direction. It is specified in standards.