A thermocouple is a temperature sensor made up of two dissimilar metal wires welded to one another at one end. Although relatively basic, thermocouples can be very durable, and they do not require an outside pour source to work. This makes them popular in many industrial, scientific, or utility applications. These devices come in a wide range of types, made up of different materials and different calibrations, which makes them customizable for a large variety of applications and situations. There are two basic categories of thermocouples – Base Metal Thermocouples (common examples: Types E, J, K, N, and T), and Noble Metal Thermocouples (common examples: Types B, C, R, and S). Base Metal thermocouples tend to be more common, since they are less expensive and can be used in a wider range of atmospheres, but Noble Metal thermocouples are extremely useful in applications whose temperature exceeds 2700ºF.
All thermocouples work due to the Seebeck Effect, discovered in 1821. Thomas Seebeck, for whom the principle is named, discovered that when two metals of dissimilar composition were joined at both ends and one end was heated, the metals created a complete thermoelectric circuit. If the circuit is broken at the center, the voltage produced by the dissimilar conductors can be read at the “cold” end, and this data can be correlated back to the temperature of the “hot” end. Each type of modern thermocouple operates on this principle regardless of what alloys the sensor is made from, and certain standard combinations of alloys have certain predictable qualities, such as a specific temperature ranges and resistance to things like corrosion.
It doesn’t seem seasonally appropriate to talk about ice and snow. After the beating most of the country took this winter between the blizzards, ice storms, and fronts of brutally cold air, most of us are more than ready for spring and trying to forget the fury Mother Nature unleashed on us over the last four months. After mentioning rime ice as a hazard in a recent post detailing how the 490-A Wind Alarm and Monitor works in tandem with Richards anemometers and wind vanes to measure and store wind and temperature information, however, it occurred to us that explaining the difference between rime ice and the other types of ice we’ve been subjected to this winter could be interesting.
There are so many other different types of ice and frost, however, that it’s become pretty clear why the Inuit people have 39 different words for snow. Not all frozen water is created equal, and it’s fascinating to find out what makes each different type unique. For now, though, we’re focusing on clear ice, rime ice, and hoarfrost.
But first, a key difference between ice and frost. Both weather phenomena are caused when water freezes, but whether frost or ice forms depends on the state of matter at the time of freezing. Ice forms when water in a liquid state comes into contact with either a freezing air mass or a freezing surface. Frost, on the other hand, occurs when water vapor, a gas, freezes, going straight from gaseous to solid. Since water vapor is less dense than liquid water, it follows that frost is less dense than ice, and generally more delicate. We all know that even tiptoeing on frosted grass in the late fall can produce that satisfying crunch, but it can take more weight and more effort to break a layer of ice. A thick sheet of ice can even support the weight of a fully loaded tractor-trailer, as we know from shows like Ice Road Truckers.
In the lower 48, we’re probably most familiar with clear ice. Clear ice is, as the name implies, very nearly transparent and appears to take on the color of whatever surface it’s frozen to. In the case of roadways and walkways, it becomes “black ice.” In the wrong light, it looks like a patch of wet pavement, leading motorists and pedestrians to think that they can get the same traction they have on the rest of the pavement. Clear ice forms when water comes into contact with a surface is at or below 0° C, either as standing water or winter precipitation. The fact that standing water can become clear ice makes “black ice” such a major cause of traffic accidents – even if there hasn’t been any precipitation recently, black ice can still form if melting has occurred and then refrozen.
Rime ice is different. It comes in two “varieties”, hard rime and soft rime, and these two varieties have slightly different characteristics. Both varieties form when supercooled water droplets in a frozen fog come into contact with a frozen object, like a tree, building, or the cups of an anemometer or the vane on a wind directional vane. The droplets in the fog cloud remain as liquid because there is nothing that they can congeal around and freeze. As soon as a solid object is introduced, the droplets freeze almost instantly. Both hard and soft rime ice are white in color and less dense than clear ice. Both of these characteristics are due to the presence of air molecules between the water molecules. Hard rime, which was a problem we faced this winter at our Willow Mountain weather monitoring station, forms when there is a high-velocity wind, which deposits the fog’s water droplets onto the windward (or wind-facing) side of an object. As more and more droplets are deposited and freeze, the formation seems to grow horizontally into the wind, unlike icicles, which grow downward due to the effects of gravity. If enough ice builds up on an anemometer or a wind vane, it can cause major damage to the equipment or, in our case, freeze it solid. In some weather monitoring locations, staff has to break hard rime off the equipment by hand as regular maintenance.
Soft rime forms when conditions are calmer and there is little to no wind. This type of rime tends to form in more delicate structures, needles and scales rather than large, solid “growths” of ice. As a result, soft rime is more easily shaken off objects, which means many people mistake it for hoarfrost. Since it forms due to the same fog cloud filled with supercooled water droplets, however, it’s still considered ice. As a more delicate crystalline structure, though, it’s of less concern for damage than hard rime, glaze ice, or clear ice, which can all build up to the point where the weight of the ice can deform or break whatever object it’s built up on.
Hoarfrost, sometimes spelled hoar frost, can also form into spiky or feathery crystals, which leads people to mistake it with soft rime. Unlike rime, however, hoarfrost is formed when water vapor freezes onto an object that is at the frost point, or the temperature that water freezes (not to be confused with the dew point, the temperature at which water vapor condenses into liquid). Hoarfrost occurs when air that is filled with water vapor drops to temperatures around or lower than -3 to -5° C (roughly 23 to 27° F). It is not dew that has frozen – that creates glaze ice, more closely related to clear ice than to frost. Hoarfrost is the product of water vapor turning directly into ice crystals, bypassing the liquid state of water entirely.
There are several different “varieties” of hoarfrost, but the distinctions between them have more to do with where the frost is found rather than wind conditions upon forming. Surface hoar is what creates the “fuzzy” patches on snow banks, plate-like structures on a snow pack, and can contribute to the sparkle we sometimes see off a snowy field in the early mornings. It can even form around the mouths of animal burrows, created by the warm, moist exhalations from the animal meeting the freezing air just outside the burrow. Air hoar, which tends to be more feathery or needle-like in appearance, forms on objects above the ground, such as tree branches or blades of grass.
Richards’ anemometers and wind directional vanes are designed in such a way that damage from rime ice, clear ice, and glaze ice is a relatively minor concern, and frost is really only a “decoration”. Our anemometers and wind directional vanes are made from stainless steel, which holds up better against the weight of built-up ice than the plastic cups found on some competing instruments. In addition, the stainless steel is covered with an anti-stick coating, which means that any ice that does form on our instruments is not solidly bonded to the metal. Our anemometers also have an internal heater, further lessening the build-up of ice on the instruments. It doesn’t prevent ice from forming completely, but it does prevent the internal bearings from being affected by the ice, which allows the instrument to continue to function even if the exterior is covered in ice. Other design features of the C5 anemometer include a slight flare to the rotor hub of the instruments, which directs water away from the shaft of the instrument and prevents the formation of ice bridges between the hub and the shaft. This doesn’t mean that our instruments absolutely cannot be covered by ice, as evidenced by the earlier pictures of hard rime buildup at Willow Mountain, but these feature make the occurrence of ice damage less likely. It’s a good thing, too – nobody was looking forward to trying to coordinate a fix in Alaska from the office in Massachusetts.
We’re hoping that Mother Nature doesn’t throw anything more than some frost and flurries at us until next winter, but at least we now have some information at our disposal to be able to tell what’s forming around us. Here, at least, we’re hoping that our Willow Mountain array escapes a freeze intact again next year like it has this year.
On Facebook, we previously linked three examples of live wind monitoring feeds, located at Blue Hills Observatory in central Massachusetts, Willow Mountain in Alaska, and here at the Arklay S. Richards factory. These three feeds are a great way to see what the weather conditions are at each of these locations, and the instruments provide accurate wind and temperature data down to the minute. There’s a live camera feed focused on each array, too, which is a nice visual perk. But did you know that this live data feed is a service that the Arklay S. Richards Company provides?
You read that right. Those data feeds are provided as a complimentary Cloud-based web interface for users of our 490-A Wind Monitor and Alarm. The 490-A links to wind instruments, such as the C5C Anemometer and the D5C Wind Vane (or FT Technologies’ Heated Ultrasonic Anemometer for locations with frequent icing conditions), in order to collect and store the wind and temperature data that these instruments provide. When a C-24154 Wireless Internet Gateway is added to the system and connected to an active internet connection, this data can then be transmitted from the 490-A Wind Monitor and Alarm to our server, and from there to the web interface.
In order to have a working system, a C5C Anemometer and a D5C Wind Vane are first installed at the location and hard-wired to the 490-A. An RTD temperature sensor can be added if temperature data is desired, and an optional webcam can also be connected to the C-24154 Wireless Internet Gateway in order to provide a real time image of what’s going on. Unusual readings from the instruments can indicate a problem with the system, but having the ability to keep an eye on the sensors remotely in order to see if repairs are needed without taking a trip out to the site is invaluable. This winter, it allowed us to keep an eye on a potentially problematic buildup of rime ice that was affecting readings at Willow Mountain, although thankfully the problems with the readings stopped once the ice melted and freed the instruments.
All three of the examples we provided have a temperature sensor in addition to the anemometer and wind vane, so the web interface shows recorded temperatures in addition to the wind direction, speed, and gust information. Beneath the display of current conditions, there are graphs showing data from the past 24 hours. The upper graph displays the temperature as recorded by the RTD, while the lower graph shows the wind speed in yellow and the gust speed in blue as recorded by the C5C Anemometer. Beneath that are displayed the averages, minimums, and maximums of the data graphed, as well as the wind direction as captured by the D5C wind vane.
Since all the data is sent straight to our server, we can store it long-term rather than just having data for a relatively short 24 hours. This historical data can be found under the appropriately titled tab on the web interface. It’s broken down initially into months, but after the desired month or months are selected, it’s further broken down into days, hours, and even minutes. This data is generated from thousands of readings per day, making it highly accurate. It’s always available from our server, and can be downloaded in excel or PDF format for use offline as needed.
On January 22, 2014, the Arklay S. Richards Co., Inc. signed an agreement with FT Technologies Ltd, based out of Middlesex England. This agreement named the Arklay S. Richards Co. as an Approved Integrated Partner, which allowed us to incorporate the FT Technologies’ FT702LT Ultrasonic Wind sensor to our industrial wind sensor product line and provide them to our wide range of industrial wind monitoring customers. FT Technologies is the leading manufacturer of ultrasonic wind instruments, and having access to this superb product allows the Arklay S. Richards Co. to create wind monitoring and alarm systems for a larger variety of industrial applications.
Gerhard Richards, Executive Vice President of the Arklay S. Richards Co., Inc., expressed his happiness on the agreement by saying, “We are very excited about adding FT Technologies’ Acoustic Resonance Wind Sensors to our existing product mix. We have found FT wind sensors to be of exceptional quality, produce a reliable signal, and have superior de-icing characteristics. We are confident the integration of FT wind sensors with our own wind monitoring and alarm products will allow us to provide a complete system with an unmatched level of performance to the industrial marketplace.” This is especially true for applications in cold climates or in areas prone to ice, because the FT702LT Series Heated Ultrasonic Anemometer has unique de-icing features not found in any of the items the Richards production department current produces.
Fred Squire, Director of Business Development at FT Technologies, was also quite pleased with the results of the agreement. He has said, “We are looking forward to working with The Arklay S Richards Co, Inc. With their reach into specialized markets and their reputation for building high quality products, this partnership with FT Technologies is expected to support our expansion into new applications.” FT Technologies’ products work very well with the Richards line, making the display and recording of data extremely easy with items such as the Richards 490-A Wind Monitor/Alarm and the Richards C-24154 wireless internet gateway, which allows for the data collected by items such as the FT702LT to be displayed in real-time.
FT Technologies’ devotion to high quality and high performance industries is a wonderful match for the Richards pledge for the same. The FT702LT unit has undergone and passed 28 independent tests, measuring how the unit withstands severe ice conditions, dust, corrosion, lightning, and vibrations.
The Arklay S. Richards Company has made it onto the big screen!
No, unfortunately our wonderful staff has not been selected to be the stars of the next big Hollywood blockbuster, but some of the Richards products have been selected for various supporting roles. Both Into the Storm, released in August 2014, and The Amazing Spider Man, released in July 2012, feature some of the best high-powered wind instruments in our line. Neither New Line Cinema nor Columbia Pictures were disappointed by the quality they received when they reached out to us.
Into the Storm follows several characters as they attempt to survive the massive storm cell threatening Silverton, Oklahoma, including high school vice-principal Gary Fuller (played by Richard Armitage), his sons Donnie (Max Deacon) and Trey (Nathan Kress), and a team of storm chasers, led by Pete Moore (Matt Walsh). Pete and his team, consisting of meteorologist Allison Stone (Sarah Wayne Collins) and camera operators Jacob Hodges (Jeremy Sumpter) and Darryl Karley (Arlen Escarpeta), have spent most of the year attempting to intercept tornadoes in order to film them from up close, an effort that wouldn’t be possible without the existence of the Titus, his heavily-armored vehicle. Part tank, part mobile weather station, the Titus is equipped with a vast array of weather sensors and safety features, including ground anchors and winch cables that, theoretically, should keep the vehicle from being carried away in a tornado. The Titus is modeled after existing storm-chasing vehicles, such the Tornado Intercept Vehicle (TIV) 1 and the TIV 2 built by Sean Casey, and the SRV Dominator built by Reed Timmer. All vehicles, fictional and factual, are designed to be part tank, part mobile monitoring station with instruments sturdy enough to measure this powerful weather phenomenon. The Titus in particular is equipped with two Richards sensors, the C5 High Speed Industrial Anemometer and the D5 Wind Directional Vane, to help it with its job of tracking wind speed and direction. Wind tunnel testing on both instruments has proven they can withstand winds of up to 230 mph, sturdy enough to withstand the power of EF5 tornados, such as the last twister seen in the film, known to produce winds of over 200 mph.
Set in New York City, The Amazing Spider-Man follows our favorite wall-crawler Spider-Man/Peter Parker (Andrew Garfield) as he goes on high-flying adventures through the glass canyons that make up his hometown. Throughout the entirety of the film, Spidey’s far more concerned with battling Lizard, aka Dr. Curt Connors (Rhys Ifans) to ensure no more human-lizard hybrids are created in the name of science, but even so, he should have some concern for wind speed and direction. After all, it wouldn’t do for our friendly neighborhood Spider-Man to be sent spinning into a building, or to drop one of the cars he rescues from falling into the East River off the Williamsburg Bridge due to an unexpectedly strong gust. The C5 High Speed Industrial Anemometer and D5 Wind Directional Vane units Columbia Pictures ordered for their sets are background pieces, intended to lend the rooftop fight sequence realism. What high-rise building, particularly any building housing a medical research company, would be without a wind-monitoring station? They need to ensure the safety of their researchers and their research. Best of all, the movie’s set designer was impressed with how the instruments looked on screen, even more so because there was no makeup or movie magic required!
Keep your eyes peeled, and maybe someday you can spot a Richards Anemometer gracing the set of another major motion picture!