A theodolite is a survey testing instrument used for measuring horizontal and vertical angles. A basic theodolite usually consists of a small sized telescope linked with mechanisms to measure horizontal and vertical angles. It has several moving parts and is quite heavy. The theodolite telescope is fixed within perpendicular axes- the vertical axis and the horizontal, or trunion, axis. The instrument is fixed on a base that can be rotated on a tripod by a leveling system. The angle to the desired point can be measured by pointing the telescope towards that particular point. The angle thus obtained can be then read on the telescope scale.
What is Theodolite Used For? Theodolite is one of the major instruments used in surveying and engineering work. In recent times, theodolites are used for many other specialized tasks too like in meteorology and rocket launch technology.
Types of Theodolite
Various theodolite types are used for surveying and other specific purposes. Some of the types of theodolite include the following.
Repeating Theodolite In this type of theodolite, several angle readings are taken on a graduated scale. The average angle measurement is then derived by dividing the accumulated sum readings by the number of observed readings. The results of repeating theodolites are reliable enough. However, this type of theodolites are confined for locations where the support is not stable or where space for using other such instruments is limited.
Direction Theodolites In this type of theodolite, the circle is arranged to be fixed while the telescope is aimed on a number of signals. Readings on the circle are for every direction. These theodolites are very good option for triangulation purpose.
Transit This is a specialized type of theodolite has a telescope that can "flip over" ("transit the scope") to let easy back-sighting and doubling of angles for error reduction. Some transit instruments are capable of reading angles directly to thirty seconds. However "transit" is considered to be a theodolite type having less precision. It also lacks such features as scale magnification and micrometers. In spite of the fact that newer precise electronic theodolites have become very popular, the transit is still used as a lightweight tool on construction sites. There are further sub types of transit like the vernier transit theodolite which can measure vertical and horizontal angles but there are other transits which cannot measure vertical angles.
A total station is considered to be a superior surveying tool compared to the theodolite due to its digital integration and all-inclusive features. A total station incorporates the functions of theodolite to determine angles and distances by an electronic distance meter. Total stations employ a combination of lasers and prisms to record digital readings of the measurements in a computer. This data can be used further analysis.
Robotic total stations have been developed that can be operated remotely. However, the total stations are expensive and need not only survey expertise, but also detailed training on software. Total stations are suitable for survey requirements over large distances, particularly over difficult terrain. The results of a total station on such environments are more accurate.
TOPCON Digital DT-200 Waterproof and Dustproof – Digital Theodolites The DT-200 series integrates the same high-quality advanced absolute circle reading technology found in Topcon's high-performance total station products for more accurate field calculations; and they continue to deliver the highest quality optics and electronics you expect to find in Topcon theodolites.
DT-200 Series Features:
- Long Battery Life
- Waterproof and Dustproof Digital Theodolites
Available in three affordable models delivering 5", 7", or 9" angle accuracy, there is a DT-200 theodolite perfect for any job. Like the DT-100 series, the DT-200 sereies weathers any wet or dust conditions in the field, allowing for a more productive day during inclement weather. All models are also compact and lightweight for easy portability; and their simple operation provides precise measurement in a functional, hassle-free package.
TOPCON Laser DT-200L Long Range High Speed and High-Preformance Laser Theodolite
The new DT-200L Series feature the same high-quality advanced absolute circle reading technology found in Topcon's high-performance total station products, and they continue to deliver the highest quality optics and electronics you expect to find in Topcon theodolites. All this, plus the addition of a laser diode that's perfect for easy, one-person alignment jobs.
DT-200L Series Features:
- Long Battery Life
- Waterproof and Dustproof Digital Theodolites
- 633nm diode laser that can
- be seen up to 50 meters away
- outside in daylight
Available in three affordable models delivering 5", 7", or 9" angle accuracy, there is a DT-200L theodolite perfect for any job. They feature waterproof and dustproof construction that stands up to even the toughest conditions so you don't have to worry about downtime due to inclement weather. All models are also compact and lightweight for easy portability; and their simple operation provides precise measurement in a functional, hassle-free package
LEICA TM5100A Industrial
The Leica Geosystems Industrial Theodolite, the world’s most accurate theodolite with highest angular accuracy, panfocal telescope and autocollimation device, set new standards, giving you more features and benefits than any other Theodolites and Total Stations in the market.
The Industry Standard The Leica TM5100A Industrial Theodolites bring precision on-site. With unrivalled precision and superb optics, our theodolites have become the standard instrument of choice in the aerospace industry for satellite alignment as well as for system and Heads Up Display alignment for combat aircraft.
Modular Flexibility No matter your requirements, no matter the task at hand, we have the instrument that get your job done.When setting out, a single-instrument system, configured to your specifications, will meet most demands. And when the need arises, the system can be expanded to a multi-instrument system.
- Proven track record with several thousand TPS5000 instruments on the market give you the highest reliability possible.
- Highest angle accuracy make Leica Geosystems Indusrial Theodolites the most precise instruments worldwide in their category.
- Completely open and programmable software interface seamlessly integrates with your standard software or with automated processes via serial communication.
- Motorization & Automation features offer completely guided and highly automated measurement of inspection and assembly processes.
- Minimal setup time within just a few minutes guarantee minimal downtime in production and assembly processes.
- Wide range of accessories and targets give you the best adaptation to your part inspection, building and tooling applications.
- Use your instrument under almost all conditions – both indoors and outdoors.
- Built-In Autocollimation Eyepiece – a recognized global standard tool for direction and coordinate-based precision alignment tasks.
The inspection package Spatial Analyzer from New River Kinematics provides a perfect solution for multiple Theodolite Systems from Leica Geosystems. The powerful Unified Spatial Metrology Network (USMN) together with a wide range of analysis functions allows to solve even the most demanding measurement tasks