Standards and samples are placed parallel to each other in a true vertical position; sturdy metal frame with plastic handle; fits up to 5 tubes; the flat area allows the holder to sit in a water bath or on a lab bench; comes without tubes
Standards
Procedure
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