SCHEDULE 1

PART 1ESSENTIAL REQUIREMENTS

DurabilityI115

1

A relevant instrument shall be designed to maintain an adequate stability of its metrological characteristics over a period of time estimated by the manufacturer, provided that it is properly installed, maintained and used according to the manufacturer’s instruction when in the environmental conditions for which it is intended.

2

After an appropriate test, taking into account the period of time estimated by the manufacturer, has been performed, the following criteria shall be satisfied—

a

Class 1.5 relevant instruments—

i

The variation of the measurement result after the durability test when compared with the initial measurement result for the flow rates in the range Qt to Qmax shall not exceed the measurement result by more than 2 %;

ii

The error of indication after the durability test shall not exceed twice the MPE in Table 3 in paragraph 13;

b

Class 1.0 relevant instruments—

i

The variation of the measurement result after the durability test when compared with the initial measurement result shall not exceed one-third of the MPE in Table 3 in paragraph 13;

ii

The error of indication after the durability test shall not exceed the MPE in Table 3 in paragraph 13.