ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel


Updated on May 20, 2013

Psychrometer | Simplest instrument to measure relative humidity level

Looking for an instrument for measuring relative humidity level? The most common humidity level measurement instrument is hygrometer, of all kinds of hygrometer, psychrometer is the simplest instrument.

Commonly used in laboratories to monitor humidity around the lab, psychrometer is very important as the researches require certain level of humidity to meet the procedure.

There are some forms of psychrometer which are available nowadays: sling psychrometer and digital psychrometer.

Who uses Psychrometer?

Besides the laboratory use, psychrometer is an instrument every meteorologist should be able to use - to predict the weather.

In America, the country of twister and tornado, this instrument is very important to predict incoming hurricane as they come with the sign of significant temperature and humidity changes.

For this reason, storm chasers put this instrument as a must-have instrument too.

It can also be used to decide a place for storage as some products, food or materials are very sensitive to certain humidity. That case, we can be ensured that we will no longer have to throw our home appliances, food or clothes due to molds.

Sling Psychrometer

The most popular Psychrometer is sling psychrometer.

Some people know this instrument as a wet and dry-bulb thermometer as it consists of two similar thermometers which are mounted together with a lever attached on a string.

The dry bulb is an ordinary thermometer which is exposed to air to measure the normal temperature of the environment. The wet bulb thermometer is wrapped in a cloth wick. The cloth used is usually an absorbent material such as cotton.

This instrument got the name of sling psychrometer because it is placed on a structure that can be spun around up in the air.

Before it is used, the absorbent cover of the wet bulb is soaked in water. Once it is taken out of the water, the psychrometer will be spun around to hasten evaporation. The evaporation of the water will cool the wet bulb. In this phase, the humidity of the atmosphere around will make account to the amount of evaporation and consequent cooling of the thermometer as it depends to it. Water is evaporated faster in drier atmosphere.

Evaporation is slow in area with high level humidity.

The air's ability to absorb humidity is measured by the wet-bulb thermometer. One the meantime, the dry-bulb one measures the normal temperature of the area. The psychrometer is usually spun about a minute. It is enough to measure the difference in the between two thermometer. The temperature shown by the wet-bulb thermometer is quickly read and recorded before the dry one as it will be changed quickly.

The instrument can be repeatedly spun several times to get more accurate data. Once all data collected, the difference on both thermometers then is matched to the chart that has been worked out by meteorologist. The relative humidity of a certain area can be found easily in this way, the bigger the difference in temperature, the more humid the atmosphere.

How to use Sling Psychrometer

Digital Psychrometer - My Top Pick

Today, the development of technology has saved us from the trouble of doing the procedure in measuring humidity with sling psychrometer.

Digital psychrometer is a great instrument that provides practical use. With the same principle used in traditional psychrometer combined with smart computer, it can give accurate measure of relative humidity around.

Below is my top pick of Digital Psychrometer

Extech RH300 Humidity Meter with Dew PointMore Info

General Tools SAM990DW PsychrometerMore Info

General Tools EP8706 Digital PsychrometerMore Info

Extech RH390 Precision Dual Display Hygro Thermometer PsychrometerMore Info

Extech RH350 Psychrometer with 2 Type K Remote Temperature ProbesMore Info


Submit a Comment

No comments yet.


This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

Show Details
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)