ISO 6487-2012 pdf free download.Road vehicles – Measurement techniques in impact tests – Instrumentation.
ISO 6487 gives requirements and recommendations for measurement techniques involving the instrumentation used in impact tests carried out on road vehicles. Its requirements are aimed at facilitating comparisons between results obtained by different testing laboratories, while its recommendations will assist such laboratories in meeting those requirements. It is applicable to instrumentation including that used in the impact testing of vehicle subassemblies. It does not include optical methods, which are the subject of
ISO 8721.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2041, Mechanical vibration, shock and condition monitoring — Vocabulary
ISO 3784, Road vehicles — Measurement of impact velocity in collision tests
ISO 4130, Road vehicles — Three-dimensional reference system and fiducial marks — Definitions
ISOITR 27957, Road vehicles — Temperature measurement in anthropomorphic test devices — Definition of the temperature sensor locations
SAE J21 1-1:2007, Instrumentation for impact test — Part 1: Electronic instrumentation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041 and the following apply.
data channel
all the instrumentation from, and including, a single transducer (o multiple transducers, the outputs of which are combined in some specified way) to, and including, any analysis procedures that may alter the frequency content or the amplitude content of data
3.2 transducer first device in a data channel used to convert a physical quantity to be measured into a second quantity (such as an electrical voltage), which can be processed by the remainder of the channel
4 Performance requirements
4.1 CFC specifications and performance requirements
The absolute value of the non-linearity of a data channel at any frequency (except if data channel is calibrated against only one point) in the CFC (channel frequency class) shall be less than or equal to 2,5 % of the value of the CAC over the whole measurement range.
The frequency response of a data channel shall lie within the limiting curves given in Figure 2 for CFCs 1 000 and 600. For CFCs 180 and 60, the frequency response of a data channel shall lie within the limiting curves given in Figure 3. The zero decibels line is defined by the calibration factor.
4.2 Phase delay time of a data channel
The phase delay time of a data channel between its input and output shall be determined; it shall not vary by more than 1/(10FH) s between 0,03 FH and FH.
4.3 Time
4.3.1 Timebase
Time reference system of DAS shall ensure that timebase is a minimum of 0,01s with an accuracy equal or better than 1%.
4.3.2 Relative time delay
The relative time delay between the signals of two or more data channels, regardless of their frequency class. shall not exceed 1 ms, excluding phase delay caused by phase shift. Two or more data channels whose signals are combined shall have the same frequency class and shall have a relative time delay not greater than 1/(10 FH) 5.
This requirement is applicable to analog signals, synchronization pulses and digital signals.
4.4 Transducer transverse sensitivity ratio of a rectilinear transducer
The transducer transverse sensitivity ratio of a rectilinear transducer shall be less than 5 % in any direction.
4.5 Calibration
4.5.1 General
As a general rule, a data channel should be calibrated once a year. Other intervals may be defined in accordance with standards, regulations or requirement specific to the application to ensure that the measuring equipment meets the requirements of this International Standard and corresponds to the intended use. The calibration shall be done against reference equipments traceable to known national or international standards through an unbroken chain. The methods used to carry out a comparison with reference equipment shall not cause an error greater than 1 % of the CAC. The use of reference equipment is limited to the range of frequencies for which it has been calibrated.
Data channel subsystems may be evaluated individually and the results factored into the accuracy of the total data channel. This can be made, for example, by an electrical signal of known amplitude simulating the output signal of the transducer, allowing a check to be made on the gain of the data channel, excluding the transducer.
4.5.2 Accuracy of reference equipment for calibration
The accuracy of the reference equipment for calibration shall be confirmed by an accredited metrology
organization.
4.5.3 Calibration procedures and uncertainties
Table 1 presents the relevant procedures.
The result of a calibration may be recorded in a document, sometimes called a calibration certificate or a calibration report.ISO 6487 pdf free download.