IS 9613 : 1980 Specification for Primary Level

1 Scope

1.1 This standard specifies the requirements of tilting typeprimary level capable of attaining standard deviation (mean squareerror) of � 0.20 mm in 1 km of double levelling.

2 References

IS 988 : 1959General requirements for optical components

IS 1399 : 1959Glossary of terms used in optical technology

IS 1632 : 1960Specification for bubbles

IS 2352 : 1963Procedure for basic climatic and durability tests foroptical instruments

IS 2754 : 1964General requirements for optical instruments

IS 8248 : 1976Specification for antireflection coating on glass opticalcomponents