An instrument aboard the science laboratory would be able to detect methane at levels of 100 parts per trillion.

Photomultiplier tubes for detecting light at very low levels.

These tensions can be detected at various levels.

The ERß3 receptor was detected at high levels in the testis.

Just because a chemical can be detected at very low levels does not necessarily mean it can affect human health.

These gases are ideal for the project because they can be detected at very low levels, he said.

(Fabaceae), in which it has been detected at levels of 11-45 ppm.

However, there are gas detectors available now which detect toxic gases at very low levels.

But it also has other chemicals so pungent that people can detect them at levels of one part in 100 million parts of air.

It is a colourless liquid with a "sweet" smell that can be detected at low levels.