Abbreviations
|
Definition
|
Compared To
|
| ppm |
parts per million / milligrams per liter |
one second every 12 days |
| ppb |
parts per billion / micrograms per liter |
one second every 32 years |
| ppt |
parts per trillion / nanograms per liter |
one second every 32,000 years |
| ND |
Not Detected |
|
| NQ |
Not Quantifiable |
|
| < |
Less than |
|
| NYA |
Not Yet Available |
|