Silicon sphere

Products / specifications


AVOGADRO-CONSTANT NA

PLANCK-CONSTANT h

 

 

BASED ON FUNDAMENTAL CONSTANTS

 



MASS-PRIMARY-NORMAL - SILICON SPHERES

 

Material

High-purity, monocrystalline, natural silicon,
consisting of 3 isotopes:
28Si (approx. 92%), 29Si (approx. 5%), 30Si (approx. 3%)

Nominal value*

1 kg

Diameter

approx. 93,6 mm

Density

approx. 2329 kg/mm³

Specifications

 

Special secondary sphere (sc++)

Secondary sphere (sc)

Mass tolerance Δm

0 / +200 mg

0 / +200 mg

Form deviation RONt

< 20 nm

< 80 nm

Surface roughness Ra

< 0,3 nm

< 1 nm

Calibration certificates (PTB)

Measurement uncertainties

U(k=2)

Special secondary sphere (sc++)

Secondary sphere (sc)

Mass in vacuum

25 µg

45 µg

Mass in air

50 µg

55 µg

Roundness

2,5 nm

50 nm, optional

Diameter

0,3 nm

-

Volume in vacuum

0,010 mm³

-

Volume in air

0,014 mm³

0,8 mm³

Density

0,004 kg/m³

0,004 kg/m³

Surface roughness

0,15 nm

0,15, optional

Layer thickness

0,4 nm, optional

-

* Other nominal values possible on request






VOLUME AND DENSITY PRIMARY NORMALS - SILICON SPHERES

Specifications

Nominal values*

1 kg

500 g

200 g

100 g

50 g

20 g

Diameter in mm

approx. 93,6

approx. 74,3

approx. 54,7

approx. 43,4

approx. 34,5

approx. 25,4

Material

High-purity, monocrystalline, natural silicon,
consisting of 3 isotopes: 28Si (approx. 92%), 29Si (approx. 5%), 30Si (approx. 3%)

Density

approx. 2329 kg/mm³

Mass tolerance Δm

0 / +200 mg

Form deviation RONt

< 1 µm

Form deviation Ra

< 10 nm

Calibration certificate (PTB)

Measurement uncertainties

U(k=2)

1 kg

500 g

200 g

100 g

50 g

20 g

Mass in air

0,10 mg

0,050 mg

0,020 mg

0,010 mg

0,006 mg

0,005 mg

Volume in air

0,0020 cm³

0,0010 cm³

0,0009 cm³

0,0008 cm³

0,0007 cm³

0,0006 cm³

Density

0,13 kg/m³

0,13 kg/m³

0,30 kg/m³

0,50 kg/m³

0,90 kg/m³

1,9 kg/m³

* Other nominal values possible on request

 

 

Avogadro project




 

 

 

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