Meteorological instruments and their function

If you are passionate about meteorology, you are surely thinking of acquiring one of the many meteorological instruments that exist or a Weather Station, truth? There are many models, but there are some that are more complete than others, depending above all on their price. In fact, the most expensive are those that can measure more climatic variables and, therefore, the most appropriate for those who want to know in depth the climate in their area, while the cheapest are more for those who conform. with knowing the temperature that is recorded during the day and perhaps knowing the ambient humidity.

Depending on what you are going to use it for, it will be interesting to know what types of meteorological instruments are there and what function does each of them have. Thus, it will be much easier for you to choose the most suitable model for you.

Thermometer, one of the meteorological instruments that we all have 

If we have to choose one of the meteorological instruments par excellence, we would all take the thermometer. It is the most used instrument because thanks to it we can know what temperature is recorded when we take a look at it. Even so, it is likely that you will find some that only measure the maximum temperature (between -31'5ºC and 51'5ºC) and others that only measure the minimum (between -44'5ºC and 40'5ºC), although the most common is that both are seen on the same station screen.

There are many types of thermometers: gas, resistance, clinical… but mercury and digital ones are used in meteorology.

Mercury thermometer

It is a sealed glass tube with mercury inside. Its volume changes as the temperature also changes. This instrument was invented by Gabriel Fahrenheit in 1714.

Digital thermometer

The most modern. They use transducer devices (such as mercury) that will then be used by electronic circuits to convert the small voltage variations obtained into numbers. In this way, the recorded temperature will appear on the display.

Meteorological rain gauge

These meteorological instruments measures the amount of water that has fallen into the area where it is placed. Each millimeter represents one liter, and on days when the rain does not stop falling, it is highly recommended to check it every 4-6h (depending on its intensity and the capacity of our rain gauge) so that the record is as accurate possible.

Types of meteorological rain gauges

There are two models of meteorological rain gauges: manual and totalizers.

• Manual: they are the cheapest. They are simply a cylindrical container made of plastic usually green in color with a graduated scale that is measured in millimeters.
• Totalizers: totalizing meteorological rain gauges improve accuracy, as they are composed of a funnel and an operator who records the falling water every 12 hours.

Hygrometer

The hygrometer will be very useful to know the percentage of relative humidity in the air what's in our area. The results are expressed between 0 and 100%. This amount represents the percentage of the amount of water vapor present in the air.

Types of hygrometers

These meteorological instruments are classified according to whether they are analog or digital.

• Analog: they stand out for being highly precise, since they detect changes in humidity in the environment almost immediately. But sometimes you have to calibrate them, so they do not usually sell much.
• digital: digitals are also accurate, although somewhat less. They do not need any type of maintenance, and also they are ready to use right after purchase.

Related article:

Everything you need to know about hygrometers

Barometer

The barometer is one that measures the weight of the air above the earth's crust, which is known by the name of atmospheric pressure. The first was invented by the physicist Torricelli in 1643 after having carried out a simple experiment:

The first thing he did was fill a glass tube with mercury that was closed at one end, and inverted it over a bucket that was also filled with mercury. Interestingly, the column of mercury dropped a few centimeters, standing still at about 76cm (760mm) tall. Thus arose the millimeter of mercury or mmHg.

But there is still something else: normal atmospheric pressure at sea level is 760mmHg, so you can have this reference data to know if the weather is going to be good or not. How? Very easy. If it drops sharply you will know that the storm is approaching; On the contrary, if it goes up slowly, you can keep the umbrella in storage for a few more days.

Anemometer

Thanks to these meteorological instruments we can know the wind speed. The most used are the so-called windlass. They measure speed in km / h.

When the wind 'hits' the windlass, it rotates. The turns it gives are read by a counter or recorded on a strip of paper if it is an anemograph.

Heliograph

The heliograph is one of the meteorological instruments that allows us to measure the time of insolation. It has to be adjusted according to the geographical latitude and according to the season of the year in which you are, since the sun varies in height as the year goes by.

The best known is the Campbell-Stokes heliograph, which consists of a glass sphere that behaves like a converging lens. When the sun's rays pass through, a card register is 'burned' and we can know the hours of sunshine that have been that day.

Nivometer

The nivometer is used to measure the amount of snow that has fallen at a given time. There are two types: laser, which must be driven into the ground in order to register, and acoustic which, thanks to an ultrasonic wave transmitter-receiver, does not need to be in contact with the snow.

In general, the more expensive a weather station is, the more comprehensive it will be. Depending on the use you want to give it, it may not be necessary to spend a lot of money because perhaps with a cheaper one you will settle. And, on the contrary, if you know that you are going to want to know more, do not hesitate to go and buy one, which may have the highest price, but surely you can enjoy it much more.