Class A and Class B difference Laboratory glassware LINEX
If you use laboratory glassware you may have notice that there is some letters, namely A’s and B’s. Those stand for CL A (Class A) and CL B (Class B).
These are very important. Let’s see the difference between them:
Class A
Class A laboratory glassware are used in more accurate volumes. This is noticed if, in the glassware, there’s an A or AS.
The glasswork that had these kind of letters are mostly used for more accurate volumes.
An example of these kind of instrument is the volumetric flask.
Class B
Class B glassware is used for less accurate measurements. The mark that usually is in the glass is the B letter.
Below you can find Tables of the tolerances used in the LINEX Laboratory glasses of volumetric pipettes and volumetric flasks and class A graduated cylinders.
Class A volumetric pipettes
Class A volumetric pipette, full * or partial **, permanent graduation, color-coded, top and bottom tip calibrated and tempered, calibrated at 20ºC, according to ISO 648 | ||
Capacity ml | Tolerance ml | Color Code |
0,5 | +/-0,005 | 2 preto |
1 | +/-0,008 | Azul |
2 | +/-0,01 | Laranja |
3 | +/-0,015 | preto |
4 | +/-0,015 | 2 vermelho |
5 | +/-0,015 | branco |
6 | +/-0,02 | 2 laranja |
7 | +/-0,02 | 2 verde |
8 | +/-0,02 | Azul |
9 | +/-0,02 | Preto |
10 | +/-0,02 | Vermelho |
11 | +/-0,02 | Branco |
15 | +/-0,03 | Verde |
20 | +/-0,03 | Amarelo |
25 | +/-0,03 | Azul |
30 | +/-0,04 | Preto |
40 | +/-0,05 | Branco |
50 | +/-0,05 | vermelho |
100 | +/-0,08 | Amarelo |
200 | +/-0,1 | azul |
*1 traço – Escoamento total
**2 traços – Escoamento parcial |
Volumetric flasks with ground and plastic stopper class A ISO 1042
Capacity ml | Grinded | Tolerance ml |
5 | 7/16 | +/-0.025 |
10 | 7/16 | +/-0.025 |
25 | 10/19 | +/-0.040 |
50 | 12/21 | +/-0.060 |
100 | 12/21 | +/-0.100 |
200 | 14/23 | +/-0.150 |
250 | 14/23 | +/-0.150 |
500 | 19/26 | +/-0.250 |
1.000 | 24/29 | +/-0.400 |
2.000 | 29/32 | +/-0.600 |
Graduated cylinders, high shape, hexagonal glass base and ISO A class n 4788 nozzle
Capacity ml | Division | Tolerance ml |
5 | 0.1 | +/-0.05 |
10 | 0.2 | +/-0.10 |
25 | 0.5 | +/-0.25 |
50 | 1.0 | +/-0.50 |
100 | 1.0 | +/-0.50 |
250 | 2.0 | +/-1.00 |
500 | 5.0 | +/-2.50 |
1.000 | 10.0 | +/-5.00 |
2.000 | 20.0 | +/-10.00 |