Search results
Results from the WOW.Com Content Network
The disc is mounted on a pole or line and lowered slowly down in the water. The depth at which the disk is no longer visible is taken as a measure of the transparency of the water. This measure is known as the Secchi depth and is related to water turbidity. Since its invention, the disk has also been used in a modified, smaller 20 cm (8 in ...
Turbid creek water caused by heavy rains. The measurement of turbidity is a key test of both water clarity and water quality. [citation needed] There are two standard units for reporting turbidity: Formazin Nephelometric Units (FNU) from ISO 7027 and Nephelometric Turbidity Units (NTU) from USEPA Method 180.1.
More accurate measurements become important in the large volumes used in commercial food production. Also, a home cook can use greater precision at times. Water at 4.0 °C (39.2 °F) may be volumetrically measured then weighed to determine an unknown measuring-utensil volume [13] without the need for a water-density adjustment. [14]
Turbidity is a measure of the cloudiness of water based on light scattering by particles at a 90-degree angle to the detector. A turbidity sensor is placed in water with a light source and a detector at a 90-degree angle to one another. The light source is usually red or near-infrared light (600–900 nm).
Settleable solids are measured as the visible volume accumulated at the bottom of an Imhoff cone after water has settled for one hour. [2]: 89–98 Turbidity is a measure of the light scattering ability of suspended matter in the water. [2]: 131–137 Salinity measures water density or conductivity changes caused by dissolved materials.
In food science, water activity (a w) of a food is the ratio of its vapor pressure to the vapor pressure of water at the same temperature, both taken at equilibrium. [1] Pure water has a water activity of one. Put another way, a w is the equilibrium relative humidity (ERH) expressed as a fraction instead of as a percentage.
See also References Further reading External links A acidulate To use an acid (such as that found in citrus juice, vinegar, or wine) to prevent browning, alter flavour, or make an item safe for canning. al dente To cook food (typically pasta) to the point where it is tender but not mushy. amandine A culinary term indicating a garnish of almonds. A dish served amandine is usually cooked with ...
When measuring water treated with water softeners, high levels of total dissolved solids do not correlate to hard water, as water softeners do not reduce TDS; rather, they replace magnesium and calcium ions, which cause hard water, with an equal charge of sodium or potassium ions, e.g. Ca 2+ ⇌ 2 Na +, leaving overall TDS unchanged [9] or even ...