Silicon sphere
Products / specifications
AVOGADRO-CONSTANT NA
PLANCK-CONSTANT h
BASED ON FUNDAMENTAL CONSTANTS
AVOGADRO-CONSTANT N A
PLANCK-CONSTANT h
BASED ON FUNDAMENTAL CONSTANTS
MASS-PRIMARY-NORMAL - SILICON SPHERES
Basicdata
| Material | Hochreines, monokristallines, natürliches Silizium, hergestellt nach dem FZ-erfahren, bestehend aus 3 Isotopen: 28Si (approx. 92%), 29Si (approx. 5%), 30Si (approx. 3%) |
|---|---|
| Nominal value** | 1 kg |
| Diameter | approx. 93,6 mm |
| Density | ca. 2329 kg/m³ |
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 | ca. 93,6 | ca. 74,3 | ca. 54,7 | ca. 43,4 | ca. 34,5 | ca. 25,4 |
| Material | Hochreines, monokristallines, natürliches Silizium, bestehend aus 3 Isotopen: 28Si (approx. 92%), 29Si (approx. 5%), 30Si (approx. 3%) | |||||
| Density | ca. 2329 kg/m³ | |||||
| Mass tolerance Δm | 0 / +200 mg | |||||
| Form deviation RONt | < 1 µm | |||||
| Surface roughness Ra | < 10 nm | |||||
Calibration certificates (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
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