Precision instruments are used in surveying to collect precise measurements that can be used for mapping, modelling and creating floor plans. Instruments for surveying are often used for other tasks outside of surveys, like collecting measurements, and their uses across other types of survey depend on the overall goal of each project.
An instrument of surveying could be theodolite, a total station, drone surveying or a transit level. These instruments are used by land surveyors to collect accurate data to assist with construction projects that have specific requirements to ensure a safe and secure build.
Theodolite
The theodolite is the predecessor of modern survey instruments. Although it is rarely used in modern surveying, it is still common to see a theodolite used in topographic surveys across different environments. The theodolite captures horizontal and vertical measurements, which can be highly accurate.
The theodolite was used in the re-triangulation of Great Britain between 1936 and 1962, using concrete trig pillars established on hills and mountains throughout the country. The data collected by the theodolite for this project was then used by the Ordnance Survey to map the entire country.
Total station or total station theodolite
The total station is a more comprehensive version of a theodolite, which combines an Electronic Distance Measurement (EDM), with a theodolite and a microprocessor capable of storing data. It is used in topographic surveys, setting out and elevation surveys. As a total station can read slope distances, it is also used in mine and quarry surveying. Measurement is done using a modulated microwave or infrared carrier signal generated by an emitter located in the instrument’s optical path. As with a 3D laser scanning survey and theodolite, a total station can only survey points in view, therefore an obstructed points will not be measurable. The signal is then reflected by a prism reflector onto the point being surveyed and the pattern produced by the return signal is read, recorded and interpreted by a microprocessor, minimising manual work. Unlike a theodolite, a total station can work with multiple angles and distances that are measured and calculate the distance between two points and take elevations. Many total stations can also remotely measure points, so data from buildings and structures can be measured without the need to visit the point.
Drone Surveying
Drone surveys are increasing in popularity, used more to survey large areas – like roof surveys – and other inaccessible areas. As well as providing a photographic record, point cloud information can also be produced to complement terrestrial laser scanning.
Transit Level
A transit level is the simplest surveying instrument and, despite its simplicity, is an incredibly useful tool, used in both surveying and building projects. Transit levels are used for horizontal lines and points, and they measure relative levels.
Like a theodolite, a transit level has a spirit that levels the device. The telescope then pivots horizontally to take readings of the height of points which can be incredibly precise. This is used for precise monitoring of buildings, dams and earthworks, where any infinitesimal movement can be tracked over time.
Lucion conducts surveys with a range of specialist equipment, selected for your project to deliver accurate results. Contact us to discuss your project with our experienced land and building surveyors.
