Search results
Results from the WOW.Com Content Network
Total organic carbon (TOC) is an analytical parameter representing the concentration of organic carbon in a sample. TOC determinations are made in a variety of application areas. For example, TOC may be used as a non-specific indicator of water quality, or TOC of source rock may be used as one factor in evaluating a petroleum play. [1]
Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. [1] High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a trait known as volatility. [2]
e. An occupational exposure limit is an upper limit on the acceptable concentration of a hazardous substance in workplace air for a particular material or class of materials. It is typically set by competent national authorities and enforced by legislation to protect occupational safety and health. It is an important tool in risk assessment and ...
The photoionization detector is an efficient and inexpensive detector for many gas and vapor analytes. PIDs produce instantaneous readings, operate continuously, and are commonly used as detectors for gas chromatography or as hand-held portable instruments. Hand-held, battery-operated versions are widely used in military, industrial, and ...
Yes, the aforementioned TVOC alert suggested opening windows, but that was just in the alert. The app itself offers no recommendations for dealing with excessive VOCs or anything else.
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10 ...
Odor detection value. Odor threshold value (OTV) (also aroma threshold value (ATV), Flavor threshold) is defined as the most minimal concentration of a substance that can be detected by a human nose. Some substances can be detected when their concentration is only few milligrams per 1000 tonnes, which is less than a drop in an Olympic swimming ...
Correcting concentrations for altitude. Air pollutant concentrations expressed as mass per unit volume of atmospheric air (e.g., mg/m 3, μg/m 3, etc.) at sea level will decrease with increasing altitude. The concentration decrease is directly proportional to the pressure decrease with increasing altitude.