This code of practice outlines the general requirements, optical specifications, and testing methods for theodolites used in land surveying. It establishes guidelines for graduation accuracy, magnification, and proper calibration to ensure reliable angular measurements in the field.
Lays down general and specific requirements for various types of theodolites used in surveying.
Quick Reference Values
magnification range20x to 30x minimum for standard surveys
plate level sensitivity20 to 60 seconds per 2 mm run
operating temperature-20°C to +50°C
Practical Notes
Always ensure parallax is completely eliminated by accurately focusing the crosshairs before taking field readings.
Perform routine checks for vertical index error and horizontal collimation error, especially after long transit.
Store the instrument in a dry, shock-resistant case to preserve optical alignment and protect from moisture.