background level การใช้

• I don't think that you would find any mercury above background levels.
• The background level emanating from the earth is about . 7 gauss.
• Its radiation was " hundreds of times " normal background levels, authorities said.
• He said no evidence of radiation above background levels was found.
• They said no radiation above normal background levels remained inside the reactor building.
• But the levels that we found in the Bay are at background levels.
• The detector compared particle activity to a background level control.
• Subsequent surveys found radiation in the scrapyard to have returned to normal background levels.
• Holly could not release Lister until the radiation had reached a safe background level.
• Even natural background levels of ozone exceed the legal limit.
• On-site air analyses also found eight different pesticides at levels significantly above background levels.
• The three commonly used interrupt levels and the background level have distinct sets of registers.
• Dry conditions will reduce populations back to background levels.
• The elements iron, manganese and aluminium are commonly enriched over background levels by volcanic ashfall.
• And radiation on a balcony facing the sarcophagus is about 80 times normal background levels.
• Van de Brooke said the samples may have detected normal background levels from car exhaust.
• Levels of cesium-137 were found to be three to ten times higher than background levels.
• And none of the equipment was emitting more radiation than slightly above background levels, they said.
• Listen to the background level of static.
• Within 14 hours after the fireworks, perchlorate levels rose 24 to 1, 028 times above background levels.