The technological advancements in the construction industry paves the way for a range of tool inventions. Right now, the designers and engineers are using a variety of instruments for different purposes. However, one of the tools that stands as a cornerstone from ancient land demarcation to modern engineering marvels is the theodolite. Its fundamental purpose is to measure the angles precisely and tailored to specific needs. In this article by Brick & Bolt, we will delve into the fascinating world of theodolites, the types of theodolite, and their applications. Read this article to understand the distinct types of theodolites and how they can improve accuracy in your results.
What is a Theodolite?
A theodolite is an instrument designed to measure horizontal and vertical angles accurately. It is employed in various tasks such as establishing precise positions, locating points, and prolonging survey lines. Theodolites consist of sophisticated telescopes, often used as universal instruments to estimate exact angular measurements. It appears larger in size and can read minute angular values, even to 1 second of arc.
Different Types of Theodolite
Theodolites are broadly classified based on their specifications. Here’s a breakdown of its types:
Types of Theodolite Based on Reading Mechanism
These are the classifications of theodolites based on their reading mechanisms:
Vernier Theodolite: It is an early form of instrument designed with a Vernier scale to measure angles. Though featuring the least modern specifications, it has been widely used in instructional settings. Unlike other theodolite types, their design is straightforward and provides an opportunity to understand the fundamental functions and components of theodolites.
Micrometer Theodolite: Micrometers are equipped with theodolites to determine more accurate readings than their Vernier counterparts. It is suitable to use in applications where you have a situation to deal with smaller angular values. Due to the arrival of digital advancement, this micrometer theodolite is no longer in use.
Electronic Theodolites: The modernized theodolite contains digital readouts and electronic systems to precisely measure angles. Due to its easy usage, accuracy, and integration with data recording devices, this type has become a prior choice for most contemporary surveying tasks.
Optical Theodolite: The optical theodolite is enabled with a glass arc to read angles. This efficient mechanism reduces parallax error and improves accuracy in measurements. Since the arrival of advanced electronic versions, the usage of optical theodolites has gradually reduced. Still, they become an ideal choice for detailed field measure.
Types of Theodolite Based on the Movement of the Telescope Around its Horizontal Axis
Under this characteristic, theodolites are classified into two different types. They are:
Transit Theodolite: It is a surveying instrument integrated with a short enough telescope that can rotate 360 degrees around its horizontal axis, flipping from face left to right. It has the ability to precisely calculate the measurements of both horizontal and vertical directions. This theodolite type is designed with advanced features and is a preferred choice for modern surveying applications.
Non-Transit Theodolite: Unlike the transit theodolite, the telescope hasn’t rotated entirely around its horizontal axis. Due to this significant limitation, the non-transit theodolites are considered obsolete in modern surveying practices.
Types of Theodolites Based on Design
Theodolite is a specialized instrument developed over the years to meet the specific construction requirements. Below are the lists of types categorized based on the design:
Vernier Transit Theodolite: This is the most widely used theodolite type to measure both horizontal and vertical angles. It is capable of rotating its telescope around 180 degrees in a vertical plane. The integration of the Vernier scale precisely reads angles with a high degree of accuracy, while the telescope is aimed at the target points. The size of this Vernier transit theodolite is based on the diameter of its main scale, which can be 15 or 20 cm.
Tavistock Theodolite: A specially designed instrument recognized for its unique reading method. It is built with the intent of improving accuracy and ease of usage. The Tavistock theodolite is particularly developed for engineering and geodetic measurements.
Watts Micrometer Theodolite: This is a well-known theodolite type equipped with a micrometer to measure fine angular values. It offers enhanced precision for engineering and geodetic measurements.
Wild T2 Theodolite: A legendary instrument influences the field of engineering and site survey industry worldwide. It is planned for a sleek and compact design, providing highly accurate measurements with enhanced durability and functionality.
Wild T4 Theodolite: It is an exceptional design used in advanced surveying work and sensitive geodetic tasks where the most accurate and fine angular measurements are needed.
Theodolite Price in India: A Buying Guide
The price of theodolites in India ranges widely based on type and specifications, from approximately ₹14,500 for basic models to over ₹2,50,000 for advanced electronic or digital sets. Popular variants include
- Manual Vernier theodolites are priced between ₹15,000 and ₹50,000
- Electronic theodolites costing ₹50,000 to ₹1,00,000 or more.
Buyers should consider various factors, including accuracy, ease of use, brand reputation, and the inclusion of accessories like tripods and carrying cases. Trusted Indian brands and suppliers offer warranty and after-sales support. For surveying professionals, investing in reliable, precise instruments is crucial, making it essential to balance features with budget when choosing theodolites in India.
Applications of Theodolite
Theodolite is used in various specialized applications, and some of them are listed below:
Surveying and Engineering: Theodolite is crucial to measure the angle between points, which efficiently helps land surveys, construction plans, and the creation of accurate maps. It also ensures the alignment of tunnels, bridges, roads, and railways to improve the functionality and structural integrity.
Construction and Building: The theodolite accurately aligns walls and other building plan and structures like corners and columns to ensure proper alignment and structural ability according to the overall plan.
Mining: Theodolite actively helps navigate and map underground mine workings to provide safe and efficient excavation. It maintains the highly precise alignment and direction during tunnel construction.
Key Differences: Theodolite vs. Total Station
The following comparison table gives the difference between the theodolite and total station:
| Feature | Theodolite | Total Station |
| Measurement Capabilities | Measures horizontal and vertical angles only | Measures angles and distances electronically |
| Data Recording | Manual recording required | Digital data recording and storage |
| Distance Measurement | Not available | Integrated Electronic Distance Measurement (EDM) |
| Operation | Usually requires two people | Can be operated by one person |
| Ease of Use | Simpler, more manual | More user-friendly with electronic displays |
| Cost | Lower, economical | Higher, more expensive |
| Surveying Functions | Basic angular measurements | Advanced functions like coordinate integration, calculations, and mapping |
| Application | Suitable for small/simple projects | Ideal for complex, large-scale surveying tasks |
| Data Transfer | Not supported | Supports electronic data transfer to computers |
Choosing the Right Theodolite for Your Construction Project
The selection of the right theodolite is important to construct a structure as you have planned. The digital type of theodolite is efficient to use in large-scale ideas, while the manual type is an affordable option for basic construction projects. Being aware of these factors would help you better:
- Before looking at the instruments, understand your project requirements, including its scale and complexity.
- The next is how precise angular measurements that your projects need to be. Estimate the level of accuracy to choose theodolite type accordingly.
- Site condition is the most significant factor to be evaluated. Consider whether you will be working in a dusty environment, harsh weather conditions, or an area with poor visibility.
- Look at the allocated budget for buying surveying equipment.
- Last but not least, you need data digitally, or just manual reading is sufficient.
Key Takeaways & Conclusion
Theodolites remain essential tools in modern construction, offering precision and reliability across project scales. At Brick & Bolt, India’s leading home construction company, we ensure the right instruments are used to maintain project accuracy and success. Our expert team understands different theodolite types and helps clients choose equipment aligned with their specific site requirements and budget. By integrating advanced surveying techniques, we deliver high-quality construction outcomes with transparency and efficiency. Need expert advice or equipment rental? Contact Brick & Bolt for a seamless consultation and cost-effective solutions that enhance your surveying and construction experience.
Frequently Asked Questions
How many types of theodolites are there?
There are many types of theodolites based on different factors. Based on telescope movements, it is classified as a transit and non-transit theodolite.
What are the three main parts of a theodolite?
Main parts of theodolite include:
- Sighting telescope
- Horizontal and Vertical circles for angle measurement
- Leveling screws for adjustment
- Stable tripod
What are the three types of traverse in theodalite?
Major types of traverses include- Closed (polygon) (6a), control-zigzag (6b) and control-linear (6c) traverses.
Why is theodolite called transit?
A theodolite is called transit when its telescope can be revolved through a complete revolution about its horizontal axis in the vertical plane.
Apoorva H P Achar