As pressure on a gas decreases, the gas expands and cools; increasing pressure makes the temperature rise. You could also express these phase changes as evaporation and condensation, which is how evaporator coils and condenser coils get their names. Refrigerants, including Freon and Puron, may never need recharging throughout the life of your AC.
1 Make sure that the start of the ruler is directly below the center of one eyeâs pupil. 2  Hold the ruler (keeping it steady and parallel to the floor); mark the location on the ruler of the other eyeâs pupil. 3  Measure the distance in millimeters between the two marks. 4  That distance will be your PD.
How To Measure Your Pulse. 1  Turn the palm side of your hand facing up. 2  Place your index and middle fingers of your opposite hand on your wrist, approximately 1 inch below the base of your hand. 3  Press your fingers down in the grove between your middle tendons and your outside bone. You should feel a throbbing - your pulse. Count the number of beats for 10 seconds, then multiply this number by 6. This will give you your heat rate for a minute. Example: If you count 12 beats in the span of 10 seconds, multiply 12 X 6 = 72. This means your Heart Rate or pulse, is 72 (or 72 beats per minute). Another popular way to measure pulse rate is by measuring it at the neck (carotid pulse). This is especially convenient during exercise.