Usually tested once a year.
If the product specification requires a cycle of less than one year, proceed as required.
If the product quality is reliable, it can be once every two years or twice every three years, with the exception of pressure gauges and strong inspection equipment.
Fire, poison gas, gas alarm and other equipment related to human life must be specifically determined.
The standard is the national measurement technical specification JJF 1139-2005 "Principles and Methods for Determining the Calibration Cycle of Measuring Instruments".
In fact, as a user of measuring instruments, it is impossible to determine the verification cycle according to the specifications.
At the same time, when the manufacturer has made the product to determine the verification cycle according to the specifications, the cycle can meet a certain requirement.
For industrial metering equipment, this cycle is generally not less than one year.
