Sling Psychrometer. Relative humidity can be measured by an instrument called a hygrometer. The simplest hygrometer – a sling psychrometer – consists of two. The Sling Psychrometer accurately determines percent relative humidity without the necessity of consulting complex tables. The Sling Psychrometer contains a. 24 Apr A sling psychrometer is an instrument that measures the relative humidity and dew point in an area. A sling psychrometer has two.

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So while you may come across certain individuals who can precisely tell whether it is going to rain or not simply by flicking their tongues to taste the air, or twitching their nostrils to smell it, others like us who are less endowed have to rely on the use of special instruments of measurement to make such predictions. The wet bulb has a cotton wick over the bulb of the thermometer, which is moistened with room temperature water.

Relative humidity can be measured by an instrument called a hygrometer. The Miami Museum of Science also has a description of Making a psychrometer. Most instruments respond to or are calibrated to read relative humidity RHwhich is the amount of water relative to the maximum at a particular temperature expressed as per cent.

This method avoids many of the pitfalls of the previous chilled-mirrors and is capable of operating drift free.

Different Types of Microscopes. During the whirling, the water evaporates from the wick, cooling the wet-bulb thermometer. She worked as a staff writer for science texts and has been published in Praxis review materials for beginning teachers. Sir John Lesliea reputed meteorologist of his time, is credited with the invention of the sling psychrometer.


Uses of Radioactive Isotopes. However, a conventional hygrometer is unable to measure properly above the frost point, and the only way to go around this fundamental problem is to use a heated humidity probe.

In these devices, water vapor is absorbed by a salt-impregnated paper strip attached to a metal coil, causing the coil to change shape. Earth-based meteorological equipment and instrumentation. The hair is hygroscopic tending toward retaining moisture ; its length changes with humidity, and the length change may be magnified by a mechanism and indicated on a dial or scale. Air—fuel ratio meter Blind spot monitor Crankshaft position sensor Curb feeler Defect detector Engine coolant temperature sensor Hall effect sensor MAP sensor Mass flow sensor Omniview technology Oxygen sensor Parking sensors Radar gun Speed sensor Speedometer Throttle position sensor Tire-pressure monitoring system Torque sensor Transmission fluid temperature sensor Turbine speed psychrometdr Variable reluctance sensor Vehicle speed sensor Water sensor Wheel speed sensor.

Weather prediction is a tricky affair. Note down the temperature indicated on both thermometers on your chart. This is measured by the wet-bulb thermometer.

It consists of two thermometers, a wet bulb and dry bulb. This instrument works on the principle of evaporation of water. This can be observed in beaches and coastal regions, where, since the air is humid, the sweat from our bodies doesn’t evaporate easily. Calculate the Humidity To calculate humidity, simply take the difference between the temperature values obtained in the previous step, and then refer to a psychrometric chart to know the humidity value.

Hygrometer – Wikipedia

Relative humidity is computed from the ambient temperature as shown by the dry-bulb thermometer and the difference in temperatures as shown by the wet-bulb and dry-bulb thermometers. They are also used in the care of wooden musical instruments such as pianos, guitars, violins, and harps which can be damaged by improper humidity conditions.


It consists of a human hair eight to ten inches [3] long, b c, Fig. The metal-paper coil hygrometer is useful for giving a dial indication of humidity changes. A sample is shown below. Of the several different types of hygrometers available for use, the sling psychrometer is the simplest, both in terms of design and ease-of-use. The number where the two meet in the chart is the relative humidity expressed as a percent.

Interpreting Barometric Pressure Readings. The term ‘psychrometer’, however, was first used in the year by German inventor Ernst Ferdinand August.

How Does a Compass Work.

The differences in weight were used to tally the humidity level. In the following sections, we shall take a closer look at the sling psychrometer, and study its working.

Sling Psychrometer

Prepare the Wick The device uses a wet bulb thermometer in addition to a normal dry one. A sling psychrometer works on the premise that evaporation is a cooling process. It is very challenging, particularly at low relative humidity, to obtain the maximal theoretical depression of the wet-bulb temperature; an Australian study in the late s found that liquid-in-glass wet-bulb thermometers were warmer than theory predicted even when considerable precautions were taken; [13] psychrojeter could lead to RH value readings that are 2 to 5 percent points too high.

The Invention of Clouds: Check new design of our homepage! It can be purchased from the market or even built at home itself by using two commercially available thermometers. These devices make measurements a lot faster but are often not allowed in explosive environments.

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