If you are interested in weather updates & want to know how to measure wind speed then understanding anemometers is valuable. Wind speed determines how soon a storm will arrive and how it affects the creation of high and low-pressure areas. Measuring wind speed is an important factor when piloting a plane or conducting an outdoor athletic activity.
What Measures Wind Speed?
Wind speed is measured by using an instrument called the anemometer. The unit of anemometer is FPM or feet per minute.
An anemometer has has five basic types. These are, Mechanical Anemometer, Pressure Tube Anemometer, Thermal Anemometer, Sound Wave Anemometer and Doppler Laser Light Anemometer. Each type has its own subcategories along with advantages and disadvantages. These characteristics make each type ideal for measuring wind speed in particular situations.
We have included photos of each type in case you’re wondering; “what does an anemometer look like?”
These anemometers are among the oldest and most popular, so how do they work? They operate by simply having the wind push on them and then measuring angles or rotations.
Mechanical Anemometers comes in three types.
Propeller / Vane Anemometers
The oldest form of what measures wind speed. These simple meters were invented by Italian architect Leon Battista Alberti in 1450. They use a plate mounted on a strip of springy metal which is faced into the wind. As wind speed increases, the plate is lifted and bent back. The change in angle of the hanging rod is measured and corresponds to wind velocity.
As you could imagine, this type of anemometer is not very accurate due to many factors. Think low wind speeds and deterioration of the plate and springs over time. A variation of this consists of attaching a ping pong ball to a string and determining wind velocity by the angle of the string as the wind pushes the ball.
The classic image of four cups rotating around a vertical pole was made possible by inventor Dr John Thomas Romney Robinson in 1845. Originally, the device would measure wind speed by counting the number of cup rotations over a time interval.
This technique was improved by the use of electronics for measuring purposes. Electrical components can either provide greater accuracy in counting rotations per time unit or act as a small generator that creates higher wattage as wind speed increases.
The use of a fan permits wind direction to be simultaneously determined with wind speed. The vane with the turbine has to be facing into the wind else the whole machine will rotate.
A handheld wind speed meter using a miniature fan has an advantage over its larger cousin. Since you’re the one doing the pointing, it will always be facing into even the lightest wind . Also, because it’s not permanently outdoors, a handheld wind speed meter isn’t threatened by winter icing.
Vane anemometers give users choices of units of measurement: m/s, ft/min, km/h, MPH and knots to accommodate different types of applications.
Another very old approach to measure wind speed is through the use of a pressure tube. First developed by James Lind in 1775, the basic idea is to start with a U-shaped tube and bend one end over to create a horizontal section. This piece will face into the wind. Liquid is placed into the tube and wind blowing into the horizontal portion will force the liquid up along the vertical section.
Modern versions have replaced the liquid with a flexible membrane. This moves in response to pressure differences, while a gauge translates this into wind speed. With no mechanical parts, this instrument for measuring wind speed can go for long periods without maintenance.
These thermal measuring devices are also known as hot wire anemometers. You start with the underlying principle that a flowing wind cools things off.
The device includes a thermostat that keeps a heated wire at a steady temperature. So, as the wind blows across the wire, it’s cooled and more electricity is used to bring it back up to its set temperature. The increased draw of electricity is what measures wind speed.
4. Sound Wave Anemometers
Types of sound wave anemometers to measure wind speed:
Acoustic Resonance Anemometers
Because sound needs gas molecules to travel through, their speed and direction can affect the speed of the sound waves. Ultrasonic anemometers use this phenomenon to calculate wind speed. They compare the travel time between a sound generator and a receiver to what it should be under no wind.
The big drawback here is that turbulence created by wind flowing around the instrument itself can distort the results. Rainfall can also play havoc with readings.
Acoustic Resonance Anemometers
While it also uses sound waves to measure wind speed, this instrument takes a different approach. It measures changes in the frequency of the waves as they collide with passing air molecules. Faster winds will cause the sound waves to compress into a higher frequency.
These anemometers are compact and very rugged however, they are not that accurate.
5. Doppler Laser Anemometers
This system relies on the same principals as an ultrasonic anemometer. The difference is that laser light is what measures wind speed.
The laser beam is split in two. One portion is used for reference while the other is aimed at the wind. If the air is rushing towards the measuring beam, the light waves reflecting off it are squeezed into a higher frequency. This is referred to blue shifting.
Laser light bouncing off air particles headed away from the detector undergo red shifting to a lower frequency. The receiving station compares this reflected light to the reference beam to calculate the speed of the moving air.
This instrument to measure wind speed is extremely accurate as well as very expensive. It also requires a lot of technical expertise to operate.
Many Choices To Measure Wind Speed
Clearly, there’s a lot of ways to use to measure wind speed. Keep in mind that some methods may not be very reliable. Others can be pretty costly and may involve unwieldy contraptions.
“What tool measures wind speed the best?” In our opinion, it comes down to cup anemometers for personal weather stations and handheld anemometers. These portable devices are accurate measures for wind speed anywhere you go. They are affordable, reliable and durable.
Q: What did the grape say when summer came to an end? A: He didn’t say anything. He just let out a little wine.
Sometimes, in the controversial world of adult beverages, the community of wine lovers is often associated with a good deal of snobbery. In a world where “luxury wines” can fetch $50-$100 a bottle and $200 bottles are not unheard of, some snobbery is to be expected, but it is also unfortunate.
In the age of antiquity, wine was more associated with happiness than a snobbish fetish. Even today, you will be able to find some surprisingly good (even great) wines in the aisles of your local mega-mart which can be enjoyed responsibly without breaking the family budget.
Fun the Old Fashioned Way
The dawn of civilization occurred when mankind moved from a wandering hunter/gatherer existence and began settling in a fixed location to raise crops. These crops are generally associated with bread making but there is a growing belief in the anthropological community that the earliest villages were more likely to be the home of beer and winemakers than bakers.
Wine making is a natural process which will occur whenever fruit juice is kept under the right conditions. A yeast spore may land and create a colony which consumes the sugar in the juice. The byproducts of this process (called fermentation) are carbon dioxide gas and alcohol.
The effects of alcohol appeared to be a sort of magic to ancient man, so it is natural that he would be willing to give up the freedom of a nomad life to make more wine.
A Product of Nature
Alcohol can also be produced by fermenting the sugars in cereal grains to make beer through a process called brewing. Brewing is a more technical process and usually, has faster and more reliable results. Both methods will result in a tasty beverage with intoxicating effects, but some people are beer people and others are wine people.
There is a story in the craft brewing community about a monastery in Belgium which sent several bottles of their spring brew to the Holy See in Rome to find out if it would be alright for them to drink during Lent. The wine-drinking Latins in Rome opened a bottle, took a taste, determined that the monks must be drinking the stuff as a form of penance, and gave their blessing.
Any fruit juice which is acidic but not too acidic, has the right balance of tannins and nutritive salts to support yeast growth, and sugar can become wine, but the perfect combination seems to occur naturally in grape juice. One of the first things that winemakers of antiquity did was select the varieties of grape which were the hardiest for their area, and which formed the most sugar during the growing season. Growing conditions change from year to year, of course, depending upon the weather, which in modern times has resulted in the concept of vintage years.
Although creating a fine wine is a time-consuming process, a certain vintage is not preferable just because it is old, but if a certain year had an especially long and mild summer, allowing the grape crop to be even more sweet and healthy, that year’s vintage will be considered more valuable.
A concept almost as important than vintage to marketing wine is terroir. Each region of the world where grapes are grown is subject to greater or lesser differences in climate, soil, length of daylight, and farming practices.
Terroir is a French term which shares its root with territory or land. The elements of terroir combine to influence the taste of wines from different regions. It is difficult to say whether the terroir of one region is, in fact, superior to that of another, but the farmers and winemakers from that region would like you to believe it is.
Weather for Wine Lovers or Not…
Location, soil conditions, elevation, and climate do not really change for an individual vineyard from year to year, but weather for wine lovers can vary a great deal. Some who are new to the concept of terroir might be tempted to point out that climate and weather are basically the same things. However, climate is a description of the conditions a region expects over a long period of time, along with other factors, while weather is what is happening at any particular moment. In other words, climate is what you expect and weather is what you get.
One of the best ways to appreciate the weather for wine lovers in a different region is to learn to understand the weather conditions where you live. The conditions you see outside your living room window will vary according to whether you live in the middle of the continent or near the shore of an ocean, whether you are in the middle of a broad plain or near a tall mountain range, or whether you are in the Northern States or closer to the Southern border. These are climatic considerations, of course, but they affect the weather in your region every day.
A personal weather station is a terrific way to begin understanding the weather in your area, and that will lead to a greater understanding of how weather works for wine lovers in the various wine regions of the world.
The fact that you and your neighbors experienced an early frost this year may not seem related to late season conditions in the Napa Valley, but understanding your local weather for wine lovers is a key to appreciating the terroir of another area.
Monitoring your local weather for a few months using a system like the Davis Vantage Vue Wireless 6250 or the Ambient Weather WS-2902C WiFi Smart Weather Station is a fun yet in-depth weather education for the whole family. Observing how conditions change from day to day puts your finger on the pulse of Mother Nature, and is a key to appreciating the mysterious way the natural world works. Best of all, these systems are easy to install and use, so you can begin learning almost immediately.
Not Sunny All the Time
Although most wine regions are known for their long, mild, and sunny weather conditions, one of the most interesting types of wine is the result of the growing season coming to a sudden close. The German term is eiswein or ‘ice wine’. It is in the wine maker’s best interest to wake until the grapes have reached their peak maturity when they are the sweetest before harvesting and pressing, thereby having more sugar in the grapes.
In some Northern regions, an early frost may set in before the grapes are harvested. Rather than ruining the vintage, the freezing of the grapes concentrates the sugars, resulting in a sweet dessert wine. The bottling of an eiswein is a rather special event. The vintner expects to bottle a normal vintage, of course. If he plans for an eiswein harvest, he runs the risk of the grapes rotting on the vine.
Eiswein may not be on the radar for traditional wine snobs, but it is a special enough treat to be aware of and just one of the ways that the weather rewards wine lovers.
Although there are many wines that sell for $50-$100 or even more per bottle, there are plenty of very good inexpensive wines available if you are willing to learn how to find them.
Many anthropologists believe that the dawn of agriculture was not so that early man could make bread, it occurred so that he could make beer and wine.
Wine is an agricultural product which is made by the natural process of fermenting fruit juices, usually grape.
Since it is an agricultural product, the weather from year to year has an important impact on the quality of the wine in the bottle.
Terroir is the concept that products grown in certain regions are unique due to differences in climate, soil conditions, elevation, latitude, and weather.
Understanding weather is important to understanding terroir because it has such a huge influence on wine.
Using a personal weather station at home will help you to understand weather in the great wine-growing regions.
Eiswein is a special product which can only be made in years when an early frost freezes the grapes and concentrates their sugars.
Are you one of those people obsessed with weather gadgets for your smartphone? Does a bad weather forecast create excitement for you and do you love weather trivia? Don’t worry, you’re in good company!
Lots of people can tell you about the winter of 1880-81 and the summer of 1936. Hurricanes, tornadoes and floods are all a part of a weather bug’s daily life.
There are many sensible reasons that may trigger your enthusiasm for all things weather. You may be a hobby gardener or even a large-scale farmer. Either way, average first-and-last frost days could be critical to your success.
Maybe you love snow skiing or sailing. In fact, any outdoor hobbies that are easier when you understand the weather that creates ideal conditions.
Want to dig deeper into your interest in meteorology? One of the most exciting ways is to explore some of the top weather gadgets for your smartphone. Some smart weather gadgets are very affordable while some are more pricey. Below we look at some of the Best In Class Weather Gadgets for Your Smartphone.
❌ Base module lacks some standard weather instruments – rain collector, weather vane, and anemometer are costly to add
❌ No backup for indoor module
❌ Relatively high cost for what comes standard
❌ Short battery life on outdoor module
Indoor module: 45x45x155 mm / 1.8x1.8x6 inches
Outdoor module: 45x45x105 mm / 1.8x1.8x4.1 inches
Mechanics & Design
Single piece of durable aluminum shell. UV-resistant.
Sensors & Measurements
Ranges from: 0°C to 50°C / 32°F to 112°F
Accuracy: ± 0.3°C / ± 0.54°FTemperature (outdoor):
Ranges from: -40°C to 65°C / -40°F to 150°F
Accuracy: ± 0.3°C / ± 0.54°FHumidity (indoor and outdoor):
Ranges from: 0 to 100%
Accuracy: ± 3%Barometer:
Ranges from: 260 to 1160 mbar / 7.7 to 37.2 inHg
Accuracy: ± 1 mbar / ± 0.03 inHgCO2 meter (indoor):
Ranges from: 0 to 5000 ppm
Accuracy: ± 50 ppm or ± 5%Sound meter:
Ranges from: 35 dB to 120 dB
iOS 9 or higher
Android 4.0 minimum required with access to Google Play
Windows Phone Compatibility
Windows Phone 8.0 minimum required
Every 5 minutes
Wi-Fi 802.11 b/g/n compatible (2.4GHz).
Supported security: Open/WEP/WPA/WPA2-personal (TKIP and AES).
Wireless connection between modules:
Long range 100m.
This top-notch weather gadget for your smartphone comes with an indoor module. This gives you vital information about your home environment, including air quality. The phone app allows you to view both past and current weather, as well as predicting future trends. It pairs with Amazon Alexa for easy voice control.
The modules are small and unobtrusive, measuring 1.8 inches in diameter by 4.1 inches high. The indoor module utilizes a USB wall adapter, while the outdoor module uses two AAA batteries. Both Apple and Android apps are available.
Outdoor temperature measures between -40 degrees F and +150 degrees F. Accessories include a rain gauge, wind gauge and additional indoor modules.
Most owners give this top weather gadget high marks. In fact it rates between 4 – 4.5 stars. Citing ease of use, battery life, connectivity and the ability to monitor the indoor temperature of their home while at work or on vacation. Many reviewers purchase an additional indoor monitor for their baby’s room.
Desired Temperature: 44° to 92°F
Display: 41° to 98°F
Sensitivity: +/- 0.9°F
Operating: 32° to 131°FHumidity Range:
Display: 20% to 90% RH
Sensitivity: +/- 5% RH
Operating: 5% to 95% RH (non condensing)
iOS 9 or higher
Windows Phone Compatibility
Wi-Fi, IEEE 802.11 b/g/n @ 2.4 GHz
Wi-Fi Protected Access (WPA/WPA2) and Wired Equivalent Privacy (WEP)
DHCP (dynamic) or static IP addressing
The Ecobee 3 smart thermostat announces itself as an intelligent Wi-Fi thermostat with room sensors. Most thermostats are located in hallways or very close to the cold air return. This means that the areas close to the thermostat are comfortable, but other places are either too hot or too cold.
The Ecobee remote sensors measure occupancy and temperature, making intelligent heating/cooling choices simple. You get mobile access to view and adjust your sensors. So, no more suffering from hot or cold spots in your home.
Users are giving the Ecobee 3 a solid 4.5 star rating. You’ll love the remote sensors that help average out the temperature within your house while “knowing” which room you are.
Its sleek matte black surface and uncluttered appearance is a bonus, and it works with Alexa for easy voice control.
Humidity Accuracy: (@ 25°C / 77°F, from 20% - 80% RH )
±3% typical ±4.5% maximum
iOS 8 or higher
Android 4.3 or higher
Windows Phone Compatibility
Requires Bluetooth 4.0+ (also known as Bluetooth LE)
Add a SensorPush G1 WiFi Gateway (sold separately) for data and alerts via the Internet. 100 meters wireless range
If you are looking for accurate humidity control, then you can’t go past the SensorPush wireless thermostat hygrometer. You’ll get temperature and humidity data from the one smart weather gadget.
Dry air can create health problems for some people. From asthma and bronchitis to eye irritations and skin conditions. Some musical instruments like grand pianos, guitars, violins and harps are sensitive to humidity extremes. Indeed, your wine cellar is an ideal location for a temperature or humidity sensor. Other locations you could use a SensorPush include a chicken incubator or cigar humidor.
Homeowners report a reduction of mold in their bathrooms using the SensorPush. Others use it in their hobby greenhouses and RV owners get peace of mind about food safety by placing one in their refrigerator while traveling on the road.
The easily accessible mobile app allows you to set up and monitor the gadget from your phone. You can download data into an Excel document from these smart weather gadgets.
A truly handy weather gadget, it fits easily into small spaces, and it scores a solid 5-star rating from users. You’ll likely be ordering more than one.
BLUETOOTH VERSION 4.1
BLUETOOTH SYSTEM ON CHIP
Nordic Semiconductor nRF52832
100 meters wireless range
Add a SensorPush G1 WiFi Gateway (sold separately) for data and alerts via the Internet.
The BlueMaestro Environment Monitor adds barometric pressure and dew point plus temperature and humidity. Wireless and shaped like a white pebble, this top weather gadgets for your Smartphone can be wall mounted with a simple adapter. It weighs just under 3 oz and measures 3.5 x 2.8 inches.
Apps are available for both iOS and Android and you can monitor from afar and download historical data. It’s affordable enough for hobby use and accurate enough for commercial applications. You’ll get up to five years from two AA batteries.
You might have to try from a couple of different rooms since you’ll be dealing with interior walls and objects, but users report finding a sweet spot upstairs to monitor their basement.
With a large, ergonomic hand crank, integrated LED flashlight, USB port for charging smartphones, mini-USB cable, and a built-in solar panel for supplemental power.
Sensors & Measurements
Receives AM/FM & Weather band Alerts from all seven NOAA (National Oceanic and Atmospheric Administration) weather band stations and the “Alert” system.
Can be charged
Can be charged
Windows Phone Compatibility
Can be charged
Automatically adapts signal through a retractable antenna.
If you live in an area that is prone to hurricanes, tornadoes or blizzards, this is the weather radio for you. Boaters will also appreciate its features.
Multiple charging options allow you to get weather updates even when you lose power for days or weeks. You can use rechargeable batteries, AAA batteries, solar power or the hand crank.
Once your FRX3 radio is charged, you can even charge your smartphone via USB. It even offers an LED flashlight and an emergency beacon .
Owners give it a solid 4-star rating. The major complaint came from owners who didn’t properly set up their radio when it arrived. So, if you truly need this for emergencies, be sure to set it up and learn how to operate it before you need it.
In this section we will discuss weather instruments:
The best way to know what the weather is doing is to step outside and feel it for yourself. Weather Measuring Instruments by themselves cannot tell us if it is a nice day, but they will measure the things that make the weather enjoyable or miserable. In this discussion, we will explore how both digital/electronic and traditional analog instruments function.
Calibration is an important concept to understand with any weather measuring instruments.
If an weather instrument is calibrated we know that whatever it is measuring will be the same as the measurements taken by other instruments. If the thermometer outside your window says the temperature is 72°F, then another thermometer in the same spot should read the same if both instruments are calibrated to the same standard.
This is very important if weather data is being shared over a weather station network like WeatherUnderground or the National Weather Service, but it is also reassuring to know that the instruments in your home weather station are accurate. Highest quality weather instruments are calibrated to NIST (National Institute of Standards and Technology) and the calibration can be tracked for the life of the instrument.
Temperature Gauges (weather instrument)
Thermometers are probably the most familiar weather instruments. Many homes have a thermometer or two mounted outside, and it is not uncommon for public buildings to have a temperature display incorporated into their signs.
Thermometers measure temperature, of course, but they do not always tell the full story when it comes to “how hot is it today?”
Measuring comfort seems subjective, but heat index and wind chill can be very useful for understanding human performance as well as comfort. Air temperature is just one element of these measurements, but it is a very important one.
If you are looking for simple and reliable temperature gauge that also show the comfort check our top pick from ThermoPro TP50 . Any gauge from your local store will also do a decent work, however the accuracy depends form brand to brand and instrument to instrument.
Liquid thermometers are traditionally the most common. They are traditionally referred to as mercury thermometers, even though real mercury is difficult to find due to its expense and the danger of accidental mercury poisoning.
Liquid thermometers take advantage of the fact that liquid expands at a known and measurable rate in response to temperature changes. The warmer the temperature, the higher the level of liquid in the thermometer tube and the level is compared to a scale built into the thermometer case, or sometimes etched into the tube itself.
The other common form of analog thermometer is the dial type. These work on the principle that different metals expand at different rates in response to temperature change. Strips of two different metals are bound together and then formed into a coil spring. As the temperature changes, the different expansion rates will force the coil to tighten or straighten. The coil is attached to a simple clockwork mechanism attached to a dial where we can read the temperature.
Digital temperature gauges include thermocouplesand thermistors. A thermocouple is similar to the bimetallic element of a dial thermometer, except that rather than turning a dial as a result of temperature changes, the two metals in the element create an electrical charge that changes according to temperature.
Thermistors are a type of electronic resistor made of metal oxides encased in epoxy or glass. As temperature changes, so do the electrical resistance of the device, which can be measured and displayed.
Wind Gauges – Weather instruments
Wind direction and speed are measured by wind vanes and anemometers. Knowing the direction the wind is coming from is important in predicting the sort of weather it will bring with it.
Traditional wind vanes are a common sight commonly seen on barn-tops and chimneys. They are mounted on the highest spot available so as to read wind direction without interference.
They consist of a pointer and a flat vertical material mounted behind a pivot point. As the wind acts on the flat element, the pointer points in the direction the wind is coming from. When mounting a wind vane, especially an electronic one, it is important to use a compass to ensure the instrument is mounted in relation to true north.
Mechanical Anemometers are instruments that measure wind speed. They take their measurement by counting the rotations of the shaft over a period of time. Cup anemometers have a vertical shaft with three or four hemispherical cups mounted on arms perpendicular to the shaft. Three cup anemometers are considered more accurate because there is less interference.
If you don’t want to buy, you can make a DIY anemometer at home. Check the procedure here and watch the video on how to make an anemometer at home.
Propeller or vane anemometers have horizontal shafts with a propeller mounted on the end. The propeller itself is intrinsically more accurate at sensing wind speed, but must be held directly into the wind, so the unit is often incorporated into a wind vane. The advantage of the cup type anemometer is that it will sense wind strength from any direction.
Wind-chill is a measurement of relative comfort. Cold weather “feels” colder since moving air removes heat from a body faster than still air. There are charts and formulas for measuring wind chill at various temperatures and wind speeds, but most electronic weather stations which have an anemometer and a temperature gage will derive wind-chill from installed software.
Atmospheric or barometric pressure measurements are helpful in predicting weather. Generally steady or rising pressure indicates fair weather while a falling pressure means a storm or foul weather is approaching.
Barometers are the instruments used to measure atmospheric pressure.
The earliest type of barometers were the liquid type. This instruments air made by drawing liquid up into a clear (glass) tube and sealing the top of the tube. The liquid is held in the tube by the vacuum created in the top portion. The open bottom is placed below the surface of an open reservoir. As air pressure increases, the liquid in the tube rises.
A more common mechanical barometer is the aneroid type. These operate by comparing pressure between the inside and outside of a sealed “can”. The can has a flexible top that will flex in or out as the outside pressure changes. A very simple aneroid barometer can be made at home by placing a rubber diaphragm over a jar.
Pull a piece of a balloon over the mouth of the jar and seal it with a rubber band.
Tape a long pencil to the diaphragm as a pointer.
As pressure drops, the diaphragm will swell out and the point of the pencil will point lower, and pressure rises the diaphragm will be forced inward and the pencil will point higher.
Electronic pressure readings used by most home weather stations (and some Smartphones) are taken by a piezoresistive strain gauge. These devices have the advantage of being extremely sensitive and accurate in a small size.
Is a measurement of the amount of moisture in the air. At specific temperatures and pressures, air can only hold a certain amount of water vapor. Relative humidity measures the amount of water vapor present compared to the amount air at the local temperature can hold. When relative humidity is 100% the air is said to be saturated.
At high relative humidity levels, liquid water cannot evaporate, and when humidity passes 100% water vapor condenses into liquid. As the temperature falls, the air will reach its saturation point, also called the “dew point”.
Humans regulate their body temperature with the evaporation of sweat. As humidity increases, evaporation of the sweat on the skin is less effective. This is the basis for the “heat index”, which measures how hot it “feels” at different temperature and humidity levels. Human performance, health, and comfort can be compromised at high heat index levels.
Measuring humidity is done with an instrument called a hygrometer. One type of analog hygrometer is a psychrometer, which consists of two thermometers. One thermometer is kept dry while the other has a moist fabric over the bulb. A
s the moisture in the fabric evaporates it cools the thermometer relative to the dry temperature and comparing the two readings give relative humidity.
Electronic hygrometers are usually of the capacitance type. The sensor has a polymer layer which absorbs moisture from the surrounding air, which changes the device’s capacitance. Most electronic weather stations mount the temperature gauge and the humidity gage near each other and use software to calculate heat index and dew point.
Analog Rain Gauges are among the most simple of all weather instruments to understand. Rainfall is measured by the amount of participation to fall over a certain area. Thus, all a rain gauge needs is a straight walled vessel with an open top. It can be as simple as a tin can placed on level ground. The disadvantage to such a simple instrument is that the observer needs to check it personally on occasion, measure the amount of liquid inside, and then dump out the water.
Electronic rain gauges measure rainfall amounts using a self-emptying tipping bucket sensor. The device consists of a funnel which directs rainfall into the bucket assembly. The bucket is divided into two chambers on either side of a teeter-totter mechanism. As the upper chamber fills, the bucket tips and that chamber spills its contents while the next chamber fills.
Every time the bucket tips, an electric switch is closed, and rainfall is measured by counting the number of times the connection is made.
Q1: What is the functional difference between a thermocouple and a thermistor?
Q2: What is the advantage of a cup type anemometer over a propeller type?
Q3: The cup type anemometer can read wind speed regardless of wind direction.
Q4: What does a falling barometer generally indicate?
Q5: Falling barometric pressure usually indicates an approaching storm or foul weather.
Q6: How does a psychrometer measure relative humidity?
Q7: How is rainfall measured?
A1: thermocouple measures the voltage generated by two dissimilar metals at different temperatures while a thermistor changes electrical resistance as temperature changes.
A2: The cup type anemometer can read wind speed regardless of wind direction.
A3: Falling barometric pressure usually indicates an approaching storm or foul weather.
A4: The psychrometer measures the difference between a wet-bulb and a dry-bulb thermometer. As greater evaporation will lower the wet-bulb temperature, there will be less temperature difference at high humidity levels.
A5: The amount of rain falling over a specific area.