The Dioptometer & Ocular Refraction

When you hear the term ocular refraction, you probably would guess that this term has something to do with our eyes or eyesight. Ocular refraction, in fact, refers to certain refractive errors in our eyes, which might indicate the need for corrective lenses. A device known as a dioptometer can be used to measure this ocular refraction and help an optometrist or ophthalmologist create a plan to improve your eyesight.

There are several different types of ocular refraction or refraction errors that are associated with eyesight. All of these “errors” are related to the shape of the eye and the eye’s inability to focus light on the retina. For instance, with a person who has near-sightedness, light will focus in front of the retina rather than on the retina. These individuals can see close objects fairly well, but object farther away will seem blurred.

For those who are far-sighted, the light will focus behind the retina causing objects that are close to the eye to appear blurry, while objects farther away might look normal.
Other refractive errors include astigmatism, which can cause objects to look blurry both near and far. Astigmatism is an error caused when the eye focuses light on the retina unevenly. A dioptometer can help an eye doctor determine the scope of each of these three refractive errors.

However, that is not the only use for the dioptometer. This optical tool also can be used to measure as well as calibrate other optical instruments. For instance, one could check the power of a microscope lens as well as the range of focus and the range of magnification. This device also could be used to measure the curvature of lenses as well as testing telescopes for astigmatism.

Some optical devices, such as cameras also might include diopter adjustment. This little dial can be very helpful for photographers with less than perfect vision. Adjusting the diopter will provide you with a more accurate view from your viewfinder. If you’ve ever noticed that what you see differs from the picture that is produced, adjusting the diopter might help. This feature also can be quite helpful if you are using manual focus when shooting pictures, rather than relying on auto-focus. It is important to note that when you want to make diopter adjustments, you should mount the camera on a tripod so that the camera will remain as still as possible.

Our own WK-29-3100 Dioptometer can be used to check the range and make the zero setting of several different focusing eyepieces of tools such as theodolites, range finders, binoculars, spectrometers, telescopes and other optical instruments. Our selection of instruments also includes the WK-29-3500 Millidioptometer, which can be used to set the diopter scale reading for various optical systems. This device also measures the spherical power and astigmatism of prisms.

If you need a dioptometer, millidioptometer or another type of optical instrument, take a look at our selection. In addition to the aforementioned devices, we have alignment telescopes, collimators, marine alidades, theodolites and much more. If you don’t see precisely what you need, our team of experts can create a custom design that meets your needs.

Optical Instruments: 3 Devices That Improve Our World

The human eye might seem like a useful tool, but this organ’s visual capacity actually is quite limited. However, there are many instances when we need to view tiny objects or objects that are far away, so humans have developed a myriad of optical instruments to aid this process.

From simple devices such as a magnifying glass to complex theodolites, optical instruments have helped us explore our world, advance scientific theory; improve industrial production and much more. Here’s a quick look at just a few optical instruments that have made the world a better place.

1. Telescopes
The word “telescope,” like so many of our words is derived from the Greek language. The “tele” portion of the word basically means far, while scope comes from the word skeptesthai, which means to look at. The first telescope was patented in 1608 by German-Dutch eyeglass maker Hans Lippershey, however there were several other individuals also developing this technology at the same time.

The following year, in fact, Galileo Galilei heard about these new inventions and immediately created one of his own, even though he had never seen one up close and in person. While the earliest inventors used the telescope as a way to view distant objects, it would be Galileo who first had the thought to use these optical instruments to view celestial objects.

Of course, today there are many different types of telescopes. At Warren Knight, we sell a variety of telescopic instruments, including alignment telescopes, wye telescopes and boresight telescopes. We also sell high-quality binoculars, an optical instrument that includes two telescopes fitted together, although you might not immediately think about telescopes when using binoculars.

2. Microscopes
While telescopes help us view distant objects, microscopes help use view the tiniest ones. The world’s most powerful microscope, which is an electron microscope, can be used to study atomic structure. Because of these optical instruments, we also have made huge advances in medical science, such as with the study of cells. Of course, microscopes also provide students with the ability to study plant and animal structures at the cellular level.

3. Theodolites
We’ve all seen theodolites, but we probably didn’t actually know it at the time. Surveyors and engineers use these devices to help them conduct road and construction surveys quite often. These optical instruments are capable of measuring angles in the horizontal plane and the vertical plane with impressive accuracy. These tasks help us build and maintain safe roads, allow us to check the integrity of bridges and ensure that buildings and homes are constructed on level ground. These are just a few of the benefits people enjoy because of theodolites.

Theodolites, however, are not just used for surveying and construction tasks, they also can be an excellent tool for a meteorologist or as a navigational aid. At Warren Knight, we offer several meteorological theodolites as well as electronic theodolite systems and an observation theodolite.

For instance, our WK-20-8400 Pilot Balloon Theodolite can be used to measure the angles of elevation and azimuth of pilot and weather balloons. These optical instruments also can be used to measure these angles in relation to aircraft, ships or other moving objects as far as 20,000 meters or greater, depending on visibility. We also produce a telemetering theodolite and an observation theodolite. The WK-20-8350 Telemetering Theodolite can be used for the calibration of navigational aids such as TACAN and VORTAC.

In addition to the Warren Knight products detailed in this article, we sell a wide range of optical instruments, leveling equipment, boresights, clinometers and everything else you might need to keep your world level and aligned. If you need a custom design, we can transform just about any product so that it meets your unique specifications.

The Optical Micrometer & Displacement

At Warren Knight, we’ve been designing and building optical instruments for more than a century. Among the many instruments on our website, you will find high-quality optical micrometers, which can be used to measure horizontal or vertical line displacement. Here’s a quick look at displacement and some facts about our micrometers and how they can be used.

Many people mistakenly believe that distance and displacement are the same. After all, Merriam-Webster lists the definition of displacement as “the difference between the initial position of something and any later position.” That certainly sounds like distance, but distance basically refers to the amount of space covered while displacement is a comparison of where something was initially and where it ended up, which isn’t always the same thing.

For instance, let’s say a person draws a chalk square on a sidewalk and each side of the square is three feet in length. We will mark each edge of the square with a letter as points A, B, C & D. If a person walks from point A to point B, the distance and displacement are the same – 3 feet. However, if a person walks from point A all the way around the square back to A again, the distance would be 12 feet and the displacement would be 0 feet. Of course, you may ask why this is so. The answer is simple, if something starts and ends at the same point, it has not been displaced but it has covered a certain distance.

But what does this have to do with optical micrometers? An optical micrometer measures this displacement, which can be handy in many situations. Micrometers are used by many types of engineers as well as scientists to determine displacement. For instance, if you are calibrating an instrument, you might begin by checking for displacement. If you are measuring changes in a rock formation, you will look at its displacement.

Our optical micrometers can be placed on a telescope barrel or adapted to fit tools such as transits, levels or theodolites, depending on your needs. The micrometers also are available in single axis or dual axis. We also have other helpful tools that incorporate a micrometer. Our WK-51-2200 Spherical Micrometer Alignment Telescope includes two micrometers to allow for precise measurements in two directions perpendicular to the line of site. If you need an alignment telescope without a micrometer, we also carry those as well.

Aside from the optical micrometer, we sell many other types of optical tooling instruments. This includes alignment collimators, theodolites, vertical transits, boresights, magnetic mirrors, dioptometers and much more. We also sell many types of clinometers, leveling equipment, navigation equipment, boresights and surveying equipment. Keep in mind, if the specifications of our optical micrometers or other optical tools don’t quite suit your needs, we usually can provide you with a custom design so if you don’t find exactly what you need, give us a call today.

The Digital Protractor & Beyond: A Look At Protractors

For most people, a protractor is simply a small plastic half circle that they used during a geometry class way back in high school. However, many people use protractors for work and tools such as a digital protractor or electronic protractor ensure that accurate measurements are taken. Here’s an in-depth look at protractors and a few of the handy products that we sell here at Warren Knight.

Protractors, as you probably know, help us measure and draw angles and these angle-measuring tasks are important for construction, surveying and navigation tasks just to name a few. Tools for angle measurement have been around for centuries, but the first official description of a protractor dates back to 1589 when English mathematician Thomas Blundeville mentioned this tool in his Briefe Description of Universal Mappes & Cardes. In this work, the protractor mainly was described as a tool for use in the creation of navigational charts.

These days, there are many different types of protractors, a combination of manual protractors and electronic protractors. At Warren Knight, we sell a wide range of protractors, both those used manually and digital protractors. For instance, our WK-23-1990 Propeller Protractor is a non-electronic protractor that can be used to measure the blade angle of propellers on airplanes. Our propeller protractor is a four-way instrument that measures angles directly between any two planes or a number of planes.

For navigational purposes, we sell two different types of three-arm protractors. These protractors look a bit more complex than a two-arm protractor and this device, not surprisingly invented by a U.S. Navy Captain, allows one to plot ship positions on a map or navigational chart.

Our transparent three-arm protractor makes it easy to see the chart or map underneath the protractor as you plot a course on a map or chart. We also offer a precise three-arm metal protractor with one fixed arm and two movable arms. This protractor includes interchangeable pivot plugs for determining or marking the location of the instrument’s center.

Of course, many of our customers rely on a digital protractor or electronic protractor for their work. These devices feature an instant display for angle, level and tilt, and many of these lightweight tools are battery-powered and can be taken easily wherever you need to go. These can be used for construction tasks, to measure the angle of a saw blade, to ensure that something is level and much more.

Our WK-35-4490 Digital Protractor is lightweight and easy-to-use with a range of plus or minus 45 degrees. A 9-volt battery will power this handheld electronic protractor for about 100 hours. Our WK-35-4445 Electronic protractor includes a digital display and an electronic clinometer. A four-foot cable is included although cable lengths up to 200 feet are available. Our WK-PRO3600 Digital Protractor provides the user with an immediate reading of all angles in a 360-degree range. The design of this protractor makes it easy to use this device with round objects, such as a pipe.

The digital protractor or electronic protractor makes it easier than ever before to measure angles as accurately as possible. If you a digital protractor any type of angle-measuring device take a look at our selection or give us a call today.

6 Interesting Facts About Leveling & Levels

It’s easy to understand why leveling is an important task. From small tasks such as installing shelves to huge undertakings such as the construction of skyscrapers, keeping things level is crucial. Here’s a quick list featuring some fun facts about leveling and some leveling equipment.

1. Leveling & Surveying Go Hand In Hand
There are several branches that fall under the category of surveying, and leveling is one of them. The object of leveling tasks is to determine the elevation of a specific point as it relates to a specific surface, such as sea level or another bench mark. Leveling also relates to the establishment of a specific surface, or datum.

2. You Can Use Barometric Pressure For Leveling
For leveling tasks that fall under the guise of surveying, you actually can use barometric pressure to determine the difference in elevation between two distinct points. For this type of leveling, a surveyor would use a device such as an altimeter or a barometer. Of course, while this is an interesting way to determine these mathematical differences, it is not precisely accurate as barometric pressure changes throughout the day. Thus, this type of leveling is rarely used and often is used as a quick first measurement when more precise calculation will be made in the future.

3. Trigonometry Also Can Be Used For Leveling
There are several distinct types of leveling, including differential, barometric and trigonometric. Differential is the most commonly used method simply because it produces the most accurate results and involves the use of highly precise equipment. Barometric, as discussed above, is rarely used as it is not accurate enough for most applications. Trigonometric leveling, as the name suggests, involves the use of trigonometry. For this type of leveling, we often use tools such as a theodolite, a precise tool which measures angles in the horizontal and vertical planes.

4. Determining Sea Level Is A Complex Process
Earlier in this article, we mentioned that sea level is often used as datum or a bench mark. After all, as we drive along the roadways, we see town and city signs that often include that destination’s elevation in regard to sea level. But how is sea level determined? After all, the water levels change with tides, climate change and other factors.

According to the National Geographic Society, scientists will measure sea levels in a given area once per hour. This data is collected and after 19 years of data has been collected, this information is used to determine the local mean sea level. These scientists also take into consideration any land movement that occurs during this 19-year period. So, the next time you use a level to determine elevation in regard to sea level, consider how much work goes into setting that bench mark.

5. Spirit Levels Are Used By Homeowners & Professionals
A spirit level, which also can be called a bubble level, is the type of level with which most people are quite familiar. These levels date back to the 17th century and are used by carpenters, contractors, masons and homeowners alike to complete a range of tasks. At Warren Knight, we sell precision frame spirit levels that can be used to measure horizontal and vertical surfaces and shapes.

6. Spirit Levels Are Components In Many Instruments
There are many instruments out there that include a spirit level, and an Abney level is one of these instruments. These levels often are used by surveyors, as they are lightweight and easy to take in to the field. They include a sighting tube and a protractor, and our Abney level includes four scales to allow the user to obtain one or more slope readings including degrees, topographic arc, chain age correction and percent of grade.

At Warren Knight, we sell a wide variety of leveling equipment, including electronic digital clinometers, digital protractors, level meters, spirit levels, a telemetric alignment system and much more. If you don’t see exactly what you need, contact us today, and we may be able to provide you with a custom design that fits your needs and budget.

The Inclinometer: Optical, Ball, Vernier & More

Inclinometer. Clinometer. Tilt meter. Level gauge. Call it what you want, this handy device makes measuring angles of slope easy and straightforward. At Warren-Knight, we build and sell a huge assortment of inclinometers, including the following.

Optical Inclinometers
Our optical clinometers can be used for calibration and alignment tasks, as well as machine setting, fire control alignment, boresighting and more. Our optical inclinometers are versatile instruments. Simply replace the standard level vial housing with a special worktable or an auto-collimating mirror, and you can use the clinometer vertically or horizontally as a precision circular measuring table for horizontal use. We have all of these accessories available on our website, including the clinometer worktable and auto-collimating mirror as well as an LED clinometer illuminator and an optical clinometer support.

Drum Inclinometers
If you need a rugged and precise instrument for measuring or determining tilt, then you need one of our handy drum clinometers. A popular choice for aerospace engineers and aircraft manufacturers, our drum inclinometers can be used on propellers and wing surfaces, as well as machine tools, shafts, production fixtures, test tables and much more.

Vernier Inclinometers
These clinometers are so named because they feature a Vernier scale, which is a graduated scale and this scale runs parallel to a fixed scale. These often are used by pipe and steel fabricators as well as engineers. The light weight of our Vernier clinometers makes them easy to take anywhere, which makes it a perfect option for various types of inspectors, such as a quality assurance inspector.

Ball Inclinometers
Our single scale ball inclinometer includes one scale in two ranges, and we also manufacture a dual scale ball clinometer which features two scales and two ranges. Lightweight and durable, these clinometers are readable to 2 degrees at a distance of 12 feet.

Pendulum Inclinometers
Pendulum clinometers are in a class all their own, literally. While most clinometers will use a level vial or bubble, a pendulum clinometer includes a weighted pendulum, just as the name suggests. We have two different models of pendulum clinometers, the WK-23-2070 model and the WK-23-2080 model. Both include the same features and capabilities, but the WK-23-2080 model is smaller in size.

Clinometers, or inclinometers if you prefer, are used for a wide variety of tasks. Mariners and aviators will use clinometers to indicate pitch and roll. Engineers and surveyors will use clinometers for a number of tasks to measure angles of slope or incline, such as when constructing a road or grading land for construction. Clinometers also are used to set the fire angle of guns and other weapons. Scientists will use inclinometers to study volcanoes and rock formations. These are just a few of the tasks that might require the use of a clinometer.

If you need any of the aforementioned clinometers, contact Warren-Knight today. For more than a century, Warren-Knight has been designing quality clinometers as well as navigational aids, optical tooling, surveying equipment, theodolites and much more.

The World Of Metrology

What makes a centimeter a centimeter? What makes an ounce an ounce? Who decided the definitions of these standards of measurement? Metrologists are the professionals tasked with the science of determining standards of weight and measurement, and their job is crucial for just about any industry.

Imagine what might occur if the measurement for one foot differed from one country to the next. For instance, let’s think about bridges and let’s assume that every country in the world but one uses the same standard of measurement for one foot. In this one lone country, their measurement for a foot is equal to only 9 inches. As you enter the country, there is a bridge with a marked clearance of 14 feet. A truck from another country enters and this truck has a height of 13 feet, 8 inches. In any other country, this truck could travel under the bridge with no trouble, but because this country uses a different measurement standard, the results could be catastrophic.

This is just one example of why we need worldwide standards of measurement. The International Bureau of Weights and Measures is the organization that sets these standards for us worldwide. In the United States, we also have an organization within the U.S. Department of Commerce that helps uphold measurement standards, the National Institute of Standards and Technology.

Metrology degrees aren’t particularly common, but there are colleges around the country that offer specialized metrology coursework and certification programs. Typically, a metrologist might have a background in physics and different types of engineering. While a few metrologists might end up working for an organization such as the International Bureau of Weights and Measures, most end up in the fields of applied metrology or legal metrology.

Legal metrology is the branch of metrology that deals with ensuring accurate measurement in regards to any type of economic transaction as well as international trade. For instance, a legal metrologist would be concerned with the accuracy of gasoline pumps and truck weighing stations. When it comes to food-related products, a legal metrologist might ensure the accuracy of food weight or perhaps the alcohol content found in a bottle of vodka or wine. These are just a few of the many areas that fall under the guise of legal metrology.

At Warren Knight, our interest in metrology relates to applied metrology and our calibration services and equipment. Calibration is a process by which we ensure that instruments and machinery are accurate. We calibrate, or measure, a device or machine or instrument against a standard device. If the device does not match the standard, then we adjust the device until it is in sync with the standard.

We provide calibration services at Warren Knight, but we also sell a wide variety of high-quality calibration equipment and precise measurement tools. For instance, our selection includes a wide range of collimators as well as optical micrometers, millidioptometers, clinometers, levels and much more. If you don’t see precisely what you need, we can provide custom design services for many applications, so feel free to contact us at any time to discuss your calibration needs or equipment needs.

Sextants, Vertical Transits & Other Cool Navigational Tools

While our navigational equipment most often is used for commercial and military navigation purposes, the hobby sailor or yachtsman also can make use of these tools. In fact, rather than simply relying on electronic equipment such as RADAR, SONAR and depth sensors, it can be smart how to use both electronic and manual navigation equipment, including the following.

1. Navigational Sextants
Sextants have been a sailor’s tool for hundreds of years, and these devices can calculate the angle between two visible objects. A sextant includes a telescope and several mirrors as well as an arc and micrometer. The person holding the sextant will use the device to measure the altitude of a star, the moon or another celestial body in relation to the horizon.

With a bit of practice, you can learn to use a sextant to determine your geographic position in terms of latitude and longitude. While it might seem easier to simply use a GPS device, being able to calculate your location without any type of electronic aid is always an excellent idea, particularly if you enjoy longer voyages at sea.

2. Vertical Transit
Generally, a vertical transit is a type of navigational device that is not likely to be needed by a private sailor. In fact, our vertical transit is designed for large commercial vessels as well as military watercraft, when one needs to independently establish sighting and pointing accuracy of an automatic tracking system or another type of radar systems. If you do need this type of vertical transit, take a look at our WK-10-0701A-VT, which can be found under the “Navigation” tab.

3. Marine Alidades
Alidades have been used for hundreds of years by navigators, surveyors and astronomers. You can purchase beautiful antique brass alidades, which can be an eye-catching (and useful) decoration for your sailboat or powerboat. Of course, the ones we make at Warren Knight look quite a bit different than the antique versions. Our WK-13-7500 Telescopic Marine Alidade includes a terrestrial telescope for viewing distance objects and an auxiliary optical system for viewing the compass card and the bubble in the level vial.

4. Binoculars
This one might seem obvious, but no sailor should be without a well-designed set of binoculars on their sailboat or yacht. Even with all of the amazing technology available to commercial sailing vessels and those in the U.S. Navy, all types of watercraft will have binoculars on board. Our WK-39-5000 Binoculars include a left eyepiece with focus adjustment for the compensation of individual eye strength and the right eyepiece includes a reticle. If you need a UV filter, that can be purchased, as well.

5. Three-Arm Protractors
Having a solid knowledge of geometry and/or trigonometry can be useful for sailors, so it might be a good idea to dust off that old high school math book and relearn some old skills. Many of the devices listed in this article require the user to make a variety of calculations, and the there-arm protractor is no exception. This device is used to help plot your course using charts or maps. Our selection of three-arm protractors includes the WK-24-1173 Transparent Three-Arm Protractor and two metal three-arm protractors, the WK-24-1175L and WK-24-1175R models.

At Warren Knight, our selection of navigation includes sextants, vertical transits, telescopic marine alidades, binoculars and there-arm protractors. For more information about these products, simply click on the “Navigation” tab on our homepage. If you have any further questions, don’t hesitate to give us a call or contact us via email.

5 Essential Meteorological Instruments

When you hear the term, “meteorology,” your local weather forecaster probably comes into mind. Meteorology is actually the science of studying the atmosphere and phenomena that relates to the atmosphere. Of course, this knowledge is applied to the daily, weekly, monthly and yearly forecasting of the weather. In order to study our atmosphere, many meteorological instruments must be used, including the following:

1. Theodolites
Most of us are more familiar with the types of theodolites used for surveying tasks. After all, we see these theodolites all of the time, used by transportation workers to study the grade of our roads. In addition to crafting surveying theodolites, the team at Warren Knight also builds theodolites suitable for metrological studies.

These meteorological instruments are known as pilot balloon theodolites, and we design these to observe and measure the angles of elevation and azimuth of pilot and weather balloons. These also can be used to measure angles of elevation in aircraft, ships and other moving objects. Among our theodolites, we also carry several electronic meteorological theodolites as well as our complete Pibal System that includes a balloon tracking theodolite and a handheld TDS Nomad PDA computer as well as 9-foot cable that connects your theodolite to the hand-held computer.

2. Weather & Pilot Balloons
As you read about our pilot balloon theodolites, it might have surprised you to learn that weather balloons are still in use today. These handy balloons, which sometimes are called ceiling balloons or perhaps a pibal, can be used to study wind conditions such as the speed and direction of the wind. These also can be used to determine the height of a cloud’s base.

Among our many meteorological instruments, we sell several different types of ceiling and pilot balloons. This includes our WK-22-3010 Ceiling Balloon, which can be used to determine cloud height by timing the ascent of the balloon. Our WK-22-3030 Pilot Balloon can be used with one of our theodolites to determine wind direction and wind speed. Lastly, our WK-22-3100 Pilot Balloon is an excellent high-altitude balloon for determining wind speed and direction. We also sell a myriad of balloon inflation kits and individual inflation kit components.

3. Barometers
These handy devices have been in use since the 17th century, and are used to measure changes in atmospheric pressure. These devices help meteorologists forecast short-term weather changes. For instance, if the barometer shows falling air pressure, this could indicate that a storm is coming. If the barometer shows a rise in pressure, a high-pressure system could bring clear skies and a drop in temperature.

4. Anemometers & Wind Socks
Both of these devices are handy tools for studying wind conditions. The anemometer features several small sideways cups at the top and as these catch the wind, they spin and measure the wind speed. The wind sock, which you still see at many airports, is a simple fabric tube attached to a pole. As the wind blows, the sock catches the wind and displays the direction and relative speed.

5. Psychrometers & Hygrometers
Determining the level of humidity and relative humidity in the air is an important task for meteorologists, and these two tools can provide that information. While these two tools look vastly different from one another, they essentially complete the same task. For most of us, knowing the relative humidity is more about understanding how comfortable we will be on a given day. For instance, if the relative humidity is above 50%, most people find this uncomfortable especially if that level of humidity is combined with a temperature above 70 degrees Fahrenheit.

These are just a few meteorological instruments that scientists and weather forecasters use to predict and study weather patterns. If you need a meteorological instrument, such as a theodolite or pilot balloon, take a look at our selection of meteorological instruments at Warren Knight. To find these instruments, simply click on the “Theodolite” tab at the top our homepage.

The Surveyor Compass & Other Cool Surveying Tools

Surveying may not be the world’s oldest profession, but it certainly has been around for thousands of years. Land surveying was a useful skill for ancient Egyptians and Greeks, who used surveyors to define boundaries and create detailed maps. Surveyors in the past and today use a variety of cool tools, including a surveyor compass, to help them with their work. Here’s a quick look at some of the tools used by those in the surveying profession in the past as well as the present.

1. The Surveyor Compass
A surveyor’s compass is an essential tool for anyone tasked with surveying. This device sometimes is called a circumferentor, but no matter what you call it, it is used to measure angles in the horizontal plane. This device includes a compass flanked by two sighting vanes, and it can be handheld or you can mount it onto a tripod or Jacob’s staff. This type of compass has been around for more than 200 years, and was used extensively for surveying tasks in the United States.

2. Surveying Chains, Ropes & Tapes
In the earliest days of surveying, highly precise equipment was centuries from being invented, and one of the earliest surveying tools was a rope or chain of a specific length. In the early 1600s, Edmund Gunter developed a standardized type of chain. This chain included 100 links and was exactly 66-feet long, and the word “chain” is still a unit of measurement for a distance of 66 feet. This unit of measurement is less commonly used today, but still was very common in the 19th and early 20th centuries.

As a fun side note, you can actually use this measurement to calculate distance. For instance, the journey from Los Angeles to New York City is about 2,451 miles or 196,080 chains. Fortunately, we have more sophisticated means to calculate the distance these days than by laying down chains over and over again.

3. Transits & Theodolites
In the world of surveying, transits and theodolites are essential tools. Both of these devices are used to measure angles, but these days the theodolite is typically the tool of choice. Transits are still in use today, but modern theodolites are much precise and accurate, which gives them the advantage in most cases.

There are actually many different types of theodolites, and these devices are used for other purposes in addition to surveying. For instance, there are many types of theodolites that are used for meteorology. At Warren Knight, we have theodolites suitable for surveying, meteorological applications and even to help with the calibration of navigation aids such as MLS, VOR, TACAN and VORTAC.

If you need a surveyor’s compass, a theodolite or other professional surveying equipment, we have many options available here at Warren Knight. For more than a century, we have been creating quality surveying, navigation and alignment instruments and optical tooling for a variety of customers. If you aren’t sure exactly what you might need, don’t hesitate to contact us at any time.