08 TECHNICAL INFORMATION | PRODUCT-SPECIFIC SECTION
CENTRIFUGE TUBES AND CULTURE TUBES
Centrifuge tubes
DURAN® centrifuge tubes are approved in accordance with DIN 58 970 (Part 2) up to a maximum relative centrifugal force (RCF = 4 000) and for filling up to their capacity with contents having a maximum density of 1.2 g/ml.
Calculation: RCF = 1.118 x 10 – 5 x r x n 2
4000 1.118 x 10 – 5 x r
n =
Example: r = 15 cm Example in the diagram: number of revolutions (n) = 4900 min –1
Culture tubes
In addition to DURAN® culture tubes, our product range also includes soda-lime culture tubes. This is a glass belonging to the third water resistance class and is one of the soda-lime glasses with a high fraction of alkaline and alkaline earth oxides.
Properties of soda-lime glass:
Physical data Linear expansion coefficient
20/300 to DIN 52328:
9.1 × 10
– 6 K –1
Transformation temperature Tg:
525 °C
Temperature fixed points at viscosity in dPa x s: 10 13 upper annealing temperature
530 °C 720 °C
10 7, 6 softing temperature 10 4 working temperature
1 040 °C
Density :
2.50 g/cm 3
Chemical data Hydrolytic class
(ISO 719)
3 1 2
Acid class Alkali class
(DIN 12 116)
(ISO 695)
Chemical composition (main components in approx. weight %) SiO 2 B 2 O 3 K 2 O Al 2 O 3
Na 2 O BaO
CaO
MgO
69
1
3
4
13
2
5
3
209
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