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Spheres Per Gram Calculation Table

How many grams of spheres do you need to purchase in order to have the correct number of spheres required for the experiment? Do you need to count the number of microparticles flowing through the device? Look it up using the spheres per gram reference tables below.

The number of spheres per gram is proportional to the true particle density (TPD) of the material, and, therefore, knowing the correct density of the material is critical. The higher the density of each sphere, the lower the number of spheres in each gram of the material.

No microsphere product is perfectly monodisperse (uniform in diameter). There is always some size distribution of particles. The tables below are designed to correlate with Cospheric's standard microsphere sizes and the corresponding particle size distributions. Our calculations are based on the assumption that average diameter is the average of upper and lower diameter specifications.

Table of The Number of Spheres per Gram for Polyethylene and Soda Lime Glass Spheres and Microspheres with Average Diameters between 5micron and 3.4mm

Note: This table assumes the mean diameter is half way between the upper and lower size. For microspheres with different densities than those listed, use the number from the density ~1g/cc column and divide by the actual density.

Sphere Size Range
Diameter
(micron)
Polyethylene Spheres
Density ~1g/cc

(spheres per gram)
Soda Lime Glass Spheres
Density ~2.5g/cc

(spheres per gram)
5-22um776,247,246310,498,898
10-22um466,274,247186,509,699
22-27um147,162,71558,630,564
27-32um74,393,55829,638,868
32-38um44,544,82417,817,929
38-45um26,721,27010,688,508
45-53um16,233,5366,467,544
53-63um9,788,5283,899,812
63-75um5,813,7202,316,223
75-90um3,401,2581,355,083
90-106um2,029,192808,443
106-125um1,239,525493,835
125-150um734,672292,698
150-180um425,157169,385
180-212um253,649101,055
212-250um154,94161,729
250-300um91,83436,587
300-355um54,37121,662
355-425um32,19612,827
425-500um19,3057,691
500-600um11,4794,573
600-710um6,7962,708
710-850um4,0251,603
850-1000um2,413961
1000-1180um1,475590
1180-1400um890354
1400-1700um513204
1700-2000um302120
2000-2360um18473
2360-2800um11144
2800-3350um6626



Table of The Number of Spheres per Gram for Silica Nanospheres and Microspheres with Average Diameters between 166 nanometer and 7.75 micron

Average Sphere Diameter
(micron)
Average Sphere Diameter
(nanometer)
Silica Microspheres
Density ~1.8 (g/cc)

(spheres per gram)
0.166um 166nm 2.32E+14
0.261um 261nm 5.97E+13
0.507um 507nm 8.14E+12
0.690um 690nm 3.23E+12
0.890um 890nm 1.51E+12
0.961um 961nm 1.20E+12
1.18um 1180nm 6.46E+11
1.54um 1540nm 2.91E+11
1.70um 1700nm 2.16E+11
1.86um 1860nm 1.65E+11
3.62um 3620nm 2.24E+10
4.08um 4080nm 1.56E+10
7.75um 7750nm 2.28E+09