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.
When either filter is placed there is a risk for bleeding and infection, the filter tilting in the IVC, or clots collecting in the filter. If several clots are trapped in the IVC filter this may cause clot formation down the IVC causing leg swelling, hyperpigmentation, or ulceration of the lower extremities.