Theodolites

Theodolites are precision optical instruments used by land surveyors and engineers to accurately measure horizontal and vertical angles. Despite the invention of more advanced surveying instruments such as Total Stations, Theodolites remain a valuable tool in a surveyor’s toolkit because they are accurate, easy to use, and typically cost lower than more advanced surveying instruments. 

Types of Theodolites

Theodolites are classified as non-digital and digital. Non-digital theodolites are the earlier versions of Theodolites that required a great deal of manual setup and computations that are prone to human errors. 

With the advent of Digital Theodolites, however, everything has become faster, simpler, and more accurate. Digital Theodolites, as the name suggests, digitally measure and display angles on a large LCD screen - no manual calculations needed. Modern Theodolites also have keypads for easy operation and data entry and most have an angle accuracy ranging from 2 to 20 seconds.

Parts of a Theodolite

A Theodolite consists of a telescope mounted on a base. This telescope has a sight on top that is used to align the target, an objective lens to sight and magnify the target, and an eyepiece where the user looks to see the target. The target is brought to focus using a focusing knob. The Theodolite’s threaded base is used to mount the instrument to a tripod. 

The internal parts of a Theodolite consist of optical plummets, a spirit or bubble level, and graduated circles. The optical plummet makes it easy to place the Theodolite exactly vertically above the survey point. The internal spirit level ensures that the Theodolite is truly level. The graduated circles are the ones responsible for surveying the angles. 

Choosing the Right Theodolite

When choosing the best Theodolite, select the model that is up to the job for you. That means it has all the features you need and will hold up to the condition you will work in, whether they are dark, dusty, damp, or downright wet. A Theodolite’s ability to resist water and dust is indicated by its IP rating, with IP66 being the highest available.

If you are going to be working in conditions of low or no light, like underground, in a tunnel, or inside a structure without windows, you would benefit from a model with a built-in reticle illuminator and backlit LCD, so that you can view its readings without having to shine a flashlight on it. If you are concerned about operating costs and downtime, look for features like a rechargeable battery pack and charger, and backup batteries. Theodolites may also include other convenient options like a sun shade, tool kit, rain cover, drying cloth, plumb bob, and carrying case.

How Much is a Theodolite?

The median price for a theodolite is in the $2000 range, though some advanced models can top $12,000, and some basic models are available for under $800. More advanced models use lasers and keep a record of measurements, allowing you to take repeated or repositioned measurements without stopping to write down the figures and come up with calculations. The data is saved and managed on a computer. This eliminates errors and facilitates fast direct entry of the data into the software.

At Tiger Supplies, we carry all top brands of Theodolites such as Sokkia, Topcon, Leica, Spectra Precision, Nikon, Cst Berger, and Northwest Instruments, giving you the assurance of quality and reliability. Browse our Store now for quality and competitively-priced Theodolites so you can work on your projects with speed and confidence.