Bubble Viscometer Procedure
Please be aware of the following accuracies when performing the test:
Temperature control: 1 °C = 10 % error
Verticality control: 5° slant = 10 % error
Tube I.D. control: 0.1 mm = 2 % error
ASTM D 1545 Timer Method
The tube has three amber ring marks at 27, 100 and 108 mm from the bottom. Fill the tube up to the 100 mm line, insert the cork down to the 108 mm line and turn the tube bottom up. Turn the tube around, start the stop watch when the air bubble crosses the 27 mm line and stop when the bubble crosses the 100 mm line.