background level


Also found in: Dictionary, Thesaurus, Financial, Encyclopedia, Wikipedia.

level

 [lev´el]
relative position, rank, or concentration.
l's of care the six divisions of the health care system: preventive care, primary care, secondary or acute care, tertiary care, restorative care, and continuing care.
background level the usual intensity of a chemical or other stimulus in the environment.
confidence level the probability that a confidence interval does not contain the population parameter.
l's of consciousness see levels of consciousness.
lowest observed adverse effect level (LOAEL) (lowest observed effect level (LOEL)) in studies of the toxicity of chemicals, the lowest dosage level at which chronic exposure to the substance shows adverse effects; usually calculated for laboratory animals.
no observed adverse effect level (NOAEL) (no observed effect level (NOEL)) in studies of the toxicity of chemicals, the highest dosage level at which chronic exposure to the substance shows no adverse effects; usually calculated for laboratory animals.
level of significance a statistical measure that serves as the cutoff point used to determine whether a null hypothesis is retained or rejected; the probability of incorrectly rejecting the null hypothesis (see Type I error).
sterility assurance level (SAL) the probability that a process makes something sterile (see sterilization). An SAL of 10−6 is the recommended probability of survival for organisms on a sterilized device. This level means that there is less than or equal to one chance in a million that an item remains contaminated or nonsterile.

back·ground lev·el

the concentration (usually low) at which a substance or agent is present or occurs at a particular time and place in the absence of a specific hazard under investigation; an example is the background level of ionizing radiation.

background level

A typical or average environmental level of a chemical, toxin or isotope under native conditions.

back·ground lev·el

(bakgrownd levĕl)
Concentration (usually low) at which a substance or agent is present or occurs at a particular time and place in the absence of a specific hazard under investigation.
References in periodicals archive ?
The observed line profiles, g(2[theta]), for the 200 and 400 lines consisted of the convolution of the specimen line profile, f(2[theta]), with the instrument line profile, k(2[theta]), Poisson noise, and a linear background level, b(2[theta]).
"That is the point when we do the surveys, we catch it before it gets above those background levels."
* How will performance be affected by possible background levels of illicit substances found on "clean" mail?
Environmental Protection Agency (EPA) have been unable to reach an agreement on the background level of radiation that can remain when the site is released for other uses," says Senator Sharon Treat.
That's because any excess helium can eventually permeate the O-rings on your vacuum system and contribute a background level that may be high enough to mask the leaks you're seeking.
Scientists use the word epidemic to describe a cluster of incidents greater than the normal background level of cases.
The size of the background level and thus the sensitivity of the assay could be manipulated by the concentration of the metrizamide in the lower phase.
Figure 2 Incomplete Worksheet Positive factors Negative factors Sound transmission class -- Normal voice 62 (STC) Background level NC -- Voice correction -- Wall STC correction -- STC reduction -- Background correction -- Total -- Total --
Stay within their experience and background level. Dodge the cleverness trap: In communication, clarity beats cleverness every time.
How do we know what the natural background level is?" Determining natural levels could be especially important in areas with high NO,, emissions from vehicles.
Make sure that both of these objects are placed in the background level. If you place either of these two objects at the card level, HyperCard will return an error message.
As it circles over the Columbia River, it takes a reading of the Earth's natural radiation and sets its instruments to that background level. It also takes a reading on its return flight low over the river two to three times a day.

Full browser ?