The instrument commonly used for taking surveying measurements may be divided into the following main classes:
- The instrument used for ranging and laying out survey line such as ranging rods, line ranger, cross-staff, optical square etc.
- Instruments used for direct measurements of length such as chain, tape, steel band etc.
- Instruments used for measurement of legngth indirectly such as tacheometric, subtense bar, Electronic Distance Measuring Instruments etc.
- Instruments used for determining direction of line such as prismatic compass, box-sextant, theodolite etc.
- Instruments used for measuring slopes and heights such as clinometer, level etc.
- Instruments used for surveying and plotting simultaneously such as plane table.
- Instruments used for surveying by photographic means such as photo-theodolite.