1 A ratio variable, has all the properties of an interval variable, and also has a clear definition of 0.0. 2  When the variable equals 0.0, there is none of that variable. 3  Variables like height, weight, enzyme activity are ratio variables.4  Temperature, expressed in F or C, is not a ratio variable. A ordinal variable, is one where the order matters but not the difference between values. 2  For example, you might ask patients to express the amount of pain they are feeling on a scale of 1 to 10. 3  A score of 7 means more pain that a score of 5, and that is more than a score of 3.
Also be sure a hole has not been punched in the bellows as this will cause a vacuum leak. The second thing that causes breaker to blow is simply an old worn out electric pump motor, especially in salt water applications. The third cause is that the holding tank is full and the vent line is plugged.
The simple cure: disconnect the vacuum line. Pressure. If the charcoal bed is clogged with dirt (there's no filter on the air intake of the canister), you tend to get vacuum in the tank while the engine runs. Pressure in the tanks leads me to suspect that there's a blockage in the pipes leading to the canister. - - Jan. ** Never let a machine know you're in a hurry ** Tom Russ Adds for the Series III. The pressure in the fuel tanks is actually a normal condition. The fuel tanks are vented to the engine's purge system via the charcoal cannister in front of the RF wheel arch. But, installed inline just before the cannister is what is called a two pound check valve.