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State Primary Standard of Unit Length

Reproduction, storage and transmission of the size of a unit of length to standards and working means of measuring equipment by the method of direct measurements and by the method of direct verification.

The unit of length is reproduced by a source of reference radiation based on a helium-neon laser, stabilized by saturated absorption in iodine vapor.

The transmission of a unit of measurement to material measures of length is carried out by the interference method.

Metrological characteristics


from 110-6 m to 1,0 m

Uncertainty by type A (uA)


Uncertainty by type B (uB)


Total standard uncertainty (uC)


Extended uncertainty (U)


Range of measurement of dashed measures of length

from 110-6 m to 1,0 m

Range of measurement of gage blocks

from 110-1 m to 1,0 m

Extended uncertainty of measuring bar measures of length (U)

from 210-8 m to 310-7 m

Extended measurement uncertainty of finite length measures (U)

from 210-8 m to 210-7 m