Search results
Results from the WOW.Com Content Network
A simple soil moisture sensor for gardeners. Soil moisture sensors measure the volumetric water content in soil. [1] Since the direct gravimetric measurement of free soil moisture requires removing, drying, and weighing of a sample, soil moisture sensors measure the volumetric water content indirectly by using some other property of the soil, such as electrical resistance, dielectric constant ...
A hygrometer is an instrument which measures the humidity of air or some other gas: that is, how much of it is water vapor. [1] Humidity measurement instruments usually rely on measurements of some other quantities, such as temperature, pressure, mass, and mechanical or electrical changes in a substance as moisture is absorbed.
In science, an observation, or observable, is an abstract idea that can be measured and for which data can be taken. Rain was one of the first quantities to be measured historically. Two other accurately measured weather-related variables are wind and humidity. Many attempts had been made prior to the 15th century to construct adequate ...
It forms part of a standard weather station and holds instruments that may include thermometers (ordinary, maximum/minimum), a hygrometer, a psychrometer, a dewcell, a barometer, and a thermograph. Stevenson screens may also be known as a cotton region shelter, an instrument shelter, a thermometer shelter, a thermoscreen, or a thermometer screen.
This data is submitted through use of software, a personal computer, and internet connection (or amateur radio) and are utilized by groups such as the National Weather Service (NWS) when generating forecast models. Each weather station submitting data to CWOP will also have an individual Web page that depicts the data submitted by that station.
The Penman-Monteith equation approximates net evapotranspiration (ET) from meteorological data as a replacement for direct measurement of evapotranspiration. The equation is widely used, and was derived by the United Nations Food and Agriculture Organization for modeling reference evapotranspiration ET 0 .
Capacitance hygrometers consist of two charged plates separated by a polymer membrane dielectric. As the membrane adsorbs water, its ability to hold a charge increases and the capacitance is measured. This value is roughly proportional to the water activity as determined by a sensor-specific calibration. [citation needed]
The Journal of Agricultural Science is a peer-reviewed scientific journal covering research on agriculture and the use of land resources. It was established in 1905 by Rowland Biffen , Alfred Daniel Hall , Thomas Barlow Wood , and Thomas Hudson Middleton and is published by Cambridge University Press .