IS 4590 : 1980 Specification for Secondary Level

1 Scope

1.1 This standard specifies the requirements of tilting typesecondary level capable of attaining standard deviation (meansquare error) of 2 mm � in 1 km of doublelevelling.

2 References

IS 988 : 1959General requirements for optical components

IS 1399 : 1959Glossary of terms used in optical technology

IS 1632 : 1960Specification for bubbles

IS 1779 : 1961Specification for 4-metre levelling staff, folding type

IS 2754 : 1964General requirements for optical instruments

IS 8248 : 1976Specification for antireflection coating on glass opticalcomponents

IS 9607 : 1980Specification for tertiary level

IS 9613 : 1980Specification for primary level