BS ISO 12384:2010 pdf free download Aerospace — Requirements for digital equipment for measurements of aircraft electrical power characteristics
1 Scope
This International Standard specifies the requirements for digital measuring methods and digital measuringequipment for aircraft electrical power characteristics,including accuracy, algorithms and digital measuringequipment.The measuring equipment should be applied mainly for the use of laboratory or rig tests.
This International Standard can be applied to digital measuring equipment which is involved in themeasurement of power electrical characteristics of the power supply system, power distributing systems andthe utilization of equipment in aircrafts.
2Normative references
The following referenced documents are indispensable for the application of this document.For datedreferences,only the edition cited applies. For undated references,the latest edition of the referenceddocument (including any amendments) applies.
ISO 1540,Aerospace -Characteristics of aircraft electrical systems
ISO 7137, Aircraft -—Environmental conditions and test procedures for airborne equipment
3Terms and definitions
For the purposes of this document, the terms and definitions given in lSO 1540 and the following apply.3.1
sampling frequency
reciprocal of sampling interval time
3.2
sampling time
total of sampling interval time
4 Symbols
Symbols used by this lnternational Standard are listed in Table 1.
5 Measurement requirements for the aircraft electric power characteristics
5.1General rules, measurement states and the admissible errors of the measurementresults
5.1.1General
The electric power characteristics measurement shall be implemented in accordance with the definitions ofISO1540 and the requirements of this International Standard.
5.1.2 Measurement states
5.1.2.1Steady state
The measurement of steady state parameters shall be processed only when negligible changes in electricalparameters appear. For example, no load state, rated load state, etc.
5.1.2.2Transient state
The measurement of transient state parameters shall be processed in the transient state.Momentaryvariations of a characteristic from its steady state limits, and back to its steady state limits may occur as aresult of a system disturbance.For example, apply the load immediately, switch from one load to another load,power bus or power source switching, building up and shut down power source,etc. The whole transientprocedure should be tested.
5.1.3 Admissible errors of the measurement results5.1.3.1 Steady state characteristics
When measuring voltages and currents within the range of waveform characteristics allowed in lSO 1540, thesteady state measurement error shall meet the following requirements:
a)voltage:
1) steady state a.c. and d.c. voltage: in the range of measurement, the absolute error of readings shall
be in the range of +0,5 %;
2) D.C.component of the a.c.voltage: the absolute error of readings shall be in the range of ±10 %;b)current:
1) steady state a.c. current: in the range of measurement, the absolute error of readings shall be in the
range of ±1 %;
2)steady state d.c. current: in the range of measurement, the absolute error of readings shall be in the
range of +0,8 %;
c)frequency:
the a.c. system: in the range of measurement, the absolute error of readings shall be in the range of±0,1 % of the nominal frequency;