IEC 62008-2005 pdf – Performance characteristics and calibration methods for digital data acquisition systems and relevant software.
1 Scope This International Standard specifies performance characteristics and calibration methods for digital data acquisition systems and relevant software to ensure that all measurement systems relying on DAQ devices meet a common standard. This standard covers: – the minimum specifications that the DAQ device manufacturer must provide to describe the performance of the analogue-to-digital module (ADM) of the DAQ device; – standard test strategies to verify the minimum set of specifications; – the minimum calibration information required by the ADM that is stored on the DAQ device; – the minimum calibration software requirements for external and self-calibration of the ADM of the DAQ device. This standard deals with low frequency signal conversion, e.g. applications such as plant control, vibration measurement, vibro-diagnostics, acoustics, ultrasonic measurements, temperature measurements, pressure measurements, measurement in power electronics, etc. 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. IEC 60748-4:1997, Semiconductor devices – Integrated circuits – Part 4: Interface integrated circuits IEC 60748-4-3:___ 1 ) , Semiconductor devices – Integrated circuits – Part 4-3: Interface integrated circuits – Dynamic criteria for analogue-to-digital converters (ADC) ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML, Guide to the Expression of Uncertainty in Measurement (GUM)
3 Terms, definitions, abbreviations and symbols 3.1 Terms and definitions For the purposes of this document, the following definitions apply. 3.1.1 analogue-to-digital module ADM analogue input of a multifunction DAQ device 3.1.2 application program interface API standardized set of subroutines or functions along with the parameters that a program can call. An API for DAQ devices allows the programmer to communicate and control the operation of the device 3.1.3 code transition level value of the input parameter of an ADM at the transition point between two adjacent output codes. The transition point is defined as the input value that causes 50 % of the output codes to be less than and 50 % to be greater than or equal to the upper code of the transition. The transition level T[k] lies between code k -1 and code k 3.1.4 data acquisition device DAQ device for entering or collecting data NOTE Multifunction DAQ devices rely on a personal computer (commercial PC, Industrial PC, Compact PCI, notebook etc.) for control. These devices are designed to meet the needs of a general-purpose measurement system. They are not designed for a specific type of measurement. DAQ devices generally provide multiple measurement modes such as analogue input, analogue output, digital input, digital output, and counter-timer functionality. This standard only deals with the ADM of a DAQ device. 3.1.5 midstep value analogue value for the centre of the step excluding the steps at the two ends of the total range of analogue values NOTE For the end steps, the midstep value is defined as the analogue value that results when the analogue value for the transition to the adjacent step is reduced or enlarged as appropriate by half the nominal value of the step width. 3.1.6 nominal midstep value specified analogue value within a step that is ideally represented and free of error by the corresponding digital output code
4 General requirements 4.1 Test procedures and measurement uncertainty estimation A common set of specifications must be presented for comparing the ADM of one DAQ device to the ADM of another DAQ device. This is especially true when different manufacturers produce the ADMs. This document includes a core set of information that allows a side-by- side comparison of ADM capabilities. DAQ devices are designed to meet their published specifications. If there is a need to verify these specifications, this standard presents procedures for testing the ADM to confirm the specifications of the DAQ device. Using the specifications listed in 4.2, the measurement uncertainty of the ADM of a DAQ device can be determined.