What does PM stand for?

Promethium

Symbol:"Pm" Atomic Number:"61" Atomic Mass: (145)amu. This is one of the elements in the lanthanide series of inner transition elements. It may also be classified as a rare earth element. This element is not found in nature and has only been created in a lab. You will not find many uses for it in real life. 

proactinium

Particle Multiplication

particulate material

Unix Xv Graphic File

Perl Module

Phase Midulation

Saint-pierre and Miquelon (country Domains)

Periodic Maintenance

Preventative Maintenance

Preventative maintenance is routine maintenance done to keep manufacturing equipment and machinery in optimal running condition and to avoid downtime due to breakdowns or repairs being needed.