• Name – Secondary standard  for time, frequency and time scale  VET 1-5 ( reference standard GEVCh)
• Purpose – Keeping and reproduction of Time and Frequency scale in the Russian Civil Service of Time and Frequency, transmission of exact time signals and time/frequency standards, establishment of atomic time scale, time check of users with national standard time
• Certification Approval  Year – 1968
• Reference value:

Range of reproducible frequency………………………..……………… 1 – 1∙10⁸ Hz

Range of reproducible time intervals……………………..………… 1∙10^-9 – 1∙10⁸ s

• Assessment of random uncertainty of unit reproduction

Frequency instability, on the intervals of 1 day-3 month. ……………         no more than 1∙10^-14

Limit of allowable discrepancy of coordinated scale of reference standard UTC from GEVCh UTC(SU) scale …………………………………………………….……… no more than 100 ns

Uncertainty of individual keeping of time scale within 90 days.………no more than 100 ns

• Assessment of residual bias of unit reproduction:

Combined uncertainty of standard……… ………………………… no more than 2∙10^-14

• The standard consists of:

The standard is a complex of measuring means and objects that provide its continuous work.

• Devices for keeping of sizes of time, frequency and timescale units

• Devices for generation, keeping and transferring of time scale and calibration frequency spectrum

• Automatic measuring and computing system of internal comparison
• Devices for external comparison and time/ frequency dissemination including:
• Devices for high precision comparison according to GPS/ GLONASS signals
• Transportable uantum clock

• Scientific custodian of standard  - Akulov Vladislav Mihajlovich

Tel. (3952) 467330, e-mail: vakulov@niiftri.irkutsk.ru