Least count of theodolite is 20 seconds.
Least count of an instrument is minimum reading that can be measured by instrument. Accuracy is more for instruments having less value of least count.
Total station and theodolite are used to measure horizontal angles as well as vertical angles in a plane.
Prismatic compass and surveyors compass are used to measure only horizontal angles. Angles may be affected by local attraction. Hence, least count of theodolite is 20 seconds.
☛ Related Questions: