Tham khảo tài liệu 'newnes sensor technology handbook 2005 yyepg lotb part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Chapter 3 from the measurement be used Will it really make a difference in the long run whether the uncertainty is 1 or 1 Will highly accurate sensor data be obscured by inaccuracies in the signal conditioning or recording processes On the other hand many modern data acquisition systems are capable of much greater accuracy than the sensors making the measurement. A user must not be misled by thinking that high resolution in a data acquisition system will produce high accuracy data from a low accuracy sensor. Last but not least the user must assure that the whole system is calibrated and traceable to a national standards organization such as National Institute of Standards and Technology NIST in the United States . Without documented traceability the uncertainty of any measurement is unknown. Either each part of the measurement system must be calibrated and an overall uncertainty calculated or the total system must be calibrated as it will be used system calibration or end-to-end calibration . Since most sensors do not have any adjustment capability for conventional calibration a characterization or evaluation of sensor parameters is most often required. For the lowest uncertainty in the measurement the characterization should be done with mounting and environment as similar as possible to the actual measurement conditions. While this handbook concentrates on sensor technology a properly selected calibrated and applied sensor is necessary but not sufficient to assure accurate measurements. The sensor must be carefully matched with and integrated into the total measurement system and its environment. 30 CHAPTER Sensor Signal Conditioning Analog Devices Technical Staff Walt Kester Editor Typically a sensor cannot be directly connected to the instruments that record monitor or process its signal because the signal may be incompatible or may be too weak and or noisy. The signal must be conditioned . cleaned up amplified and put into a compatible format. The following
