For a sample having extraneous matter, the sample should be sieved through IS sieve 30 Ensure no air bubbles or water remain entrapped after heating the sample An air oven can be used to avoid overheating the bottom of the container. Or a sand bath can also be used. The needle is so adjusted that it just touches the bitumen sample- it should not penetrate the bitumen surface beforehand If there is any movement of the container while the needle is penetrating, the test should be discarded.