Search results
Results from the WOW.Com Content Network
A thermo-hygrograph. A thermo-hygrograph or hygrothermograph is a chart recorder that measures and records both temperature and humidity (or dew point).Similar devices that record only one parameter are a thermograph for temperature and hygrograph for humidity.
A wet bulb temperature taken with air moving at about 1–2 m/s is referred to as a screen temperature, whereas a temperature taken with air moving about 3.5 m/s or more is referred to as sling temperature. A psychrometer is a device that includes both a dry-bulb and a wet-bulb thermometer.
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.
The wet-bulb temperature is the lowest temperature that may be achieved by evaporative cooling of a water-wetted, ventilated surface.. By contrast, the dew point is the temperature to which the ambient air must be cooled to reach 100% relative humidity assuming there is no further evaporation into the air; it is the temperature where condensation (dew) and clouds would form.
In hot summer weather, a rise in relative humidity increases the apparent temperature to humans (and other animals) by hindering the evaporation of perspiration from the skin. For example, according to the heat index, a relative humidity of 75% at air temperature of 80.0 °F (26.7 °C) would feel like 83.6 ± 1.3 °F (28.7 ± 0.7 °C). [13] [14]
The pad type moisture meter is non-invasive in nature and requires only surface contact with the wood to obtain a reading. [7] [8] The non-invasive meter creates a low-frequency electrical wave between the two pads and measures the electrical properties of the wood, similar to the invasive pin-type meter. [9]
These stations transmit parameters necessary for decision-making to a base station: air temperature and relative humidity, precipitation and leaf wetness (for disease prediction models), solar radiation and wind speed (to calculate evapotranspiration), water deficit stress (WDS) leaf sensors and soil moisture (crucial to irrigation decisions).
The intake air temperature sensor is visible outside, the film-grid is inside. A hot wire mass airflow sensor determines the mass of air flowing into the engine's air intake system. The theory of operation of the hot wire mass airflow sensor is similar to that of the hot wire anemometer (which determines air velocity).