9. shot (n.) a consecutive series of pictures that constitutes a unit of action in a film
The vacuum level is determined by the pressure differential between the evacuated volume and the surrounding atmosphere. Several units of measure can be used. Most refer to the height of a column of mercury â usually inches of mercury (in.-Hg) or millimeters of mercury (mm-Hg).
Measuring intake manifold vacuum, while cranking the engine, is a very easy test that can eliminate compression as the cause for a no start. Gasoline engines that have at least three inches (3) of manifold vacuum when the engine is at normal cranking speed should have enough compression to start.