EN 1434-1:2007 (E)
2
Contents Page
Foreword..............................................................................................................................................................4
1 Scope ......................................................................................................................................................5
2 Normative references ............................................................................................................................5
3 Types of instrument...............................................................................................................................5
3.1 General....................................................................................................................................................5
3.2 Complete instrument .............................................................................................................................5
3.3 Combined instrument............................................................................................................................5
3.4 Hybrid instrument (often called a "compact" instrument) ................................................................5
3.5 Sub-assemblies of a heat meter, which is a combined instrument..................................................5
3.5.1 General....................................................................................................................................................5
3.5.2 Flow sensor ............................................................................................................................................6
3.5.3 Temperature sensor pair.......................................................................................................................6
3.5.4 Calculator ...............................................................................................................................................6
3.6 Equipment under test (EUT) .................................................................................................................6
4 Terms, definitions and symbols...........................................................................................................6
5 Rated operating conditions ..................................................................................................................9
5.1 Limits of temperature range .................................................................................................................9
5.2 Limits of temperature differences........................................................................................................9
5.3 Limits of flow-rate ..................................................................................................................................9
5.4 Limit of thermal power ..........................................................................................................................9
5.5 Maximum admissible working pressure; PS ......................................................................................9
5.6 Nominal pressure; PN .........................................................................................................................10
5.7 Limits in ambient temperature ...........................................................................................................10
5.8 Limits in deviations in supply voltage...............................................................................................10
5.9 Maximum pressure loss......................................................................................................................10
6 Technical characteristics....................................................................................................................10
6.1 Materials and construction .................................................................................................................10
6.2 Requirements outside the limiting values of the flow rate..............................................................10
6.3 Display ..................................................................................................................................................11
6.4 Protection against fraud .....................................................................................................................11
6.5 Supply voltage .....................................................................................................................................11
6.6 Qualifying immersion depth of a temperature sensor .....................................................................12
6.7 The influence on a temperature sensor pair caused by mounting in pockets..............................12
6.8 Reproducibility.....................................................................................................................................12
6.9 Repeatability.........................................................................................................................................12
6.10 Software................................................................................................................................................12
7 Specified working range .....................................................................................................................13
7.1 General..................................................................................................................................................13
7.2 Temperature difference.......................................................................................................................13
7.3 Flow rate ...............................................................................................................................................13
8 Heat transmission formula .................................................................................................................13
9 Metrological characteristics (Maximum Permissible Error, MPE) ..................................................14
9.1 General..................................................................................................................................................14
9.2 Values of maximum permissible errors ............................................................................................14
9.2.1 Maximum permissible relative errors of complete heat meters .....................................................14
9.2.2 Maximum permissible relative error of sub-assemblies .................................................................15
9.3 Application of maximum permissible errors ....................................................................................15
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