title: Per meg
text: # Per meg
  
  Per meg equals 0.001 permil or 0.0001 percent or parts per million ppm. The unit is typically used in isotope analysis by multiplying an isotope ratio in delta annotation, for example $δ^{18}O,$ by 1000000. This annotation is typically used in studies of atmospheric trace gases, where a high precision is needed for a significant interpretation of results.
  
  