ECOTEST DKG-21 M Operating Manual page 24

Failure
requirements stated in 3.2.3.
3.2.36.2 Average operating life till the first major
repair, not less than 10000 hours, and average service
life, not less than 10 years.
Limit tolerance state criterion is deviation of parameters
from the values stated in 3.2.3 that cannot be eliminated.
3.2.36.3 Average
consistent with the requirements of GOST В 9.003-80
(if stored in heated rooms and unheated storehouses in
the manufacturer's package) is 10 years.
criterion is
shelf
nonconformity
life under
23
to the
conditions