The refrigerant flows through the coils on the back or under the freezer and through an expansion valve to the inside of the freezer. As the refrigerant passes through the expansion valve the pressure drops and hence the temperature also drops.
The noun MM has 1 sense: 1  1. a metric unit of length equal to one thousandth of a meter. 2  Meaning: 3  A metric unit of length equal to one thousandth of a meter. 4  Classified under: 5  Nouns denoting quantities and units of measure. 6  Synonyms: 7  millimeter; millimetre; mm. 8  Hypernyms (mm is a kind of...):
Mm Measurement. What Is Mm In Measurement. M in chemistry stands for molarity, measured in moles per liter. m stands for milli in most fields. So this is a 0.005 M solution of sodium nitrate. There are 0.005 moles per liter of solution. Adding to Randy's explanation, you could also say there are 5 millimoles per liter.