It is usually verified once a year.
if the period required in the product manual is less than one year, it shall be carried out as required.
if the product quality is reliable, it can be used once every two years or twice every three years, except for pressure gauges and strong inspection equipment.
The life-related equipment cycle such as fire, poisonous gas and gas alarm shall be specially determined.
The standard is the National Metrology Technical Specification JJF 1139-25 Principles and Methods for Determining Verification Period of Measuring Instruments.
In fact, as a user of measuring instruments, it is impossible to determine the verification period according to the specifications.
at the same time, when the manufacturer has determined the verification cycle of the products according to the specifications, the cycle can meet a certain requirement.
for industrial metering equipment, this period is generally not less than one year.
Extended information:
The basis for determining the verification period is:
(1) the performance of measuring instruments, especially the level of long-term stability and reliability;
(2) conditions of use;
(3) frequency of use;
(4) the maintenance ability of the user;
(5) qualification of periodic verification over the years;
(6) Other factors that affect the measurement accuracy and long-term stability.
Baidu Encyclopedia-Periodic Verification