변위, 속도, 가속도 중에 선택
변위와 속도 그리고 가속도는 서로 미적분을 통해서 변환이 가능하다. 그런데 실질적으로 일방적인 방법으로만 활용된다. 일반적으로 가속도센서를이용하여 속도로 적분변환하여 평가할 수 있지만 변위를 통해 미분하여 속도로 평가하지는 않는다. 이 것은 변위센서의 약점때문이다.
다음은 변위와 속도 그리고 가속도의 용도와 주요 범위를 설명하였다. 왜? 변위를 사용하는지... 왜? 속도로 평가하는지... 왜? 가속도는 그렇게 많이 사용하는지를 이해하기 바란다. ...............
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The results of the vibration diagnosis can be confirmed
as a technical report, which is largely divided into a simple diagnosis report
and a detailed diagnosis report, etc., and is prepared including the cause and
evaluation of the current vibration problem, and a description of
countermeasures if necessary. The meaning of each report is a simple report in the case of
simple evaluation of phenomena and absolute standards after temporary
measurement, and detailed analysis to the extent that current causes can be
analyzed and countermeasures can be found through spectrum analysis and cause
analysis of various vibrations. are treated as detailed reports. In general, the
definition of regular textbooks for facility diagnosis qualifications is not
very different.
Simple diagnosis and precise diagnosis,
offline and online
First of all, if you look at the methods of simple
diagnosis, there are 'route measurement' and 'online monitoring system'. Inspection is commonly
referred to as 'off-line' as a method in which humans intermittently
investigate and record the state of equipment using a portable instrument
(vibration meter, data collector). On the other hand, constant monitoring is a method of
continuously monitoring by a monitoring device and is called 'on-line'. Inspection called
off-line can measure many measurement points and directions, but it cannot be
said to be continuous depending on the frequency of measurement. There are
advantages and disadvantages between the two systems, since on-line
continuously monitors and stores near real-time data from already installed
sensors.
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BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr
#PDM; Resonance analysis, #frequency
analysis, #CBM, #vibration sensor, #vibration and noise education
회전기계의 간이설비진단과 정밀설비진단
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진동진단의 결과는 기술보고서로 확인해 볼 수 있는데 이 것은 간이진단보고서와 정밀진단보고서 등으로 크게 구분하여 현재의 진동문제에대한 원인과 평가, 필요에 따라서 대책에 대한 기술등을 포함하여 작성된다. 각 보고서의 의미는 일시적 측정 후 간단히 현상과 절대기준 등의 평가를 한 경우는 간이보고서로, 스펙트럼분석과다양한 진동의 원인분석 등을 통해서 현재의 원인을 분석하고 대책을 구할 수 있을 정도의 상세한 분석은 정밀보고서로 다루어 진다. 대체로 설비진단 자격을 위한 정규 교과서 등에 이에 관한 정의도 크게 다르지 않다.
간이진단과 정밀진단 그리고 오프라인과 온라인
우선, 간이진단의 방법을 살펴보면 ‘점검(Route measurement)’과 ‘상시감시(Online Monitoring system)’가 있다. 점검은 흔히 설비의 상태를 인간이 포터블 계측기(진동계, Data collector) 등을 사용하여 간헐적으로 조사하고 기록하는 방법으로 'Off-line'이라고 부른다. 반면에 상시감시는 감시 장치에 의해 연속적으로 감시하는 방법으로 'On-line'이라고 하는데 off line이라 일컫는 점검은 많은 측정지점과 방향을 측정할 수 있으나 측정빈도에따라서 연속적이라고는 할 수 없고 ............
All copyright 한국CBM(주) written by BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr
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When playing an acoustic guitar, when a
guitar string is plucked according to a musical notation chord, each of the six
strings (strings) generates a harmonic sound that shows a special timbre
according to the chord, even if it produces a different sound. The guitar sound
is unique for each string, and the pitch of the sound is different from each
other. To understand this reason, if you take a good look at it with a little
common sense, you can understand that the sound is 'uniquely
different' depending on the length of the guitar string
being plucked, the type of guitar string, and the degree to which the guitar
string is tightened.
On the other hand, the vibration
generated when the fan is operated, and the RPM (revolutions per minute) that
fluctuates whenever the accelerator is pressed are different from the unique
characteristics of the above guitar strings. In other words, this is a newly
created thing, a 'forced creation', on the
other hand, it is different from what the guitar string originally had, in
other words, it does not generate sound at all unless it is plucked by hand.
Forced frequency
When a force is applied, both a natural frequency and a forced frequency occur, but .....
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copyright korea CBM written by BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr
Vibration/Displacement/Measurement/Analysis/Cause
Analysis/Monitoring System Design/Building Vibration Noise/Structural
Vibration/Rotating Machine Vibration/Resonance Analysis/Feature
Frequency/FFT/Facility Diagnosis/Early Fault Diagnosis/Noise Vibration Frequency
Analysis/Vibration Soundproofing/Plant Vibration noise/construction site
construction road/railway/measuring equipment and sensor
consulting/PDM,CBM,VMS,CMS/machine-structure-piping-building-construction
site-railway/monitoring system (HW, SW) design/MODAL/ODS/vibration
certification/ Building Vibration/Technical Advisory/Research Review/Vibration
and Noise Education Lecture/Company of Noise and Vibration Engineers/Korea
CBM/kcbm.kr
강제주파수는 고유주파수와 무엇이 다른가? (소음과 진동분야에서 주파수의 원인별 구분)
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통기타를 연주할 때, 악보코드에 맞추어 기타줄을 튕기면 6개의 각 선(현)들은 다른 음을 발생하더라도 코드에 맞게 특별한 음색을 보이는 하모닉 음이 발생한다. 기타음은 각 줄별로 독특하고 소리의 높낮이가 서로 다르다. 이 이유를 알기위해 약간의 상식을 갖고 잘 살펴보면 튕기고 있는 기타줄의 길이와 기타줄의 종류 그리고 기타줄이 조여있는 정도에 따라서 소리가 '고유하게 다르다'는 것을 이해 할 수 있다.
반면에, 선풍기를 작동시키면 발생하는 진동, 자동차의 엑셀을 밟을 때마다 변동하는 RPM(분당 회전수)은 위의 기타줄에서 발생하는 고유한 특성과는 다르다. 즉, 이 것은 새롭게 생성되는 것, '강제로 만들어 내는 것'이며 반면에 기타줄은 원래 가지고 있었던 것, 쉽게 말하자면 손으로 튕기지 않으면 소리가 아예 처음부터 발생하지 않는다는 것과의 차이이다.
강제주파수(Forced frequency)
어떤 힘을 가하면 고유주파수와 강제주파수는 각각 모두 발생하지만 강제주파수는 만들어 생성된 값이고 고유주파수는 원래부터 있던 값이다. 이 두 개의 주파수가 ........
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Selection of displacement, velocity, and acceleration sensors
such as amplitude units
Since the output voltage or current is proportional to each unit, the selection of the unit is not very different from the selection of the sensor. Sensors mainly used for diagnosing and monitoring equipment
1. Eddy current type displacement sensor (Proximity) that
directly measures the behavior of a shaft supported by a sleeve bearing in a
non-contact manner.
2. Accelerometer, which propagates shaft vibration to
rolling bearing and measures it indirectly by contact method outside the
bearing housing (indirectly transmitted to the housing by impact of the bearing
connected to the shaft)
3. There is a velocity transducer that works without power.
However, among these, the speed sensor is very precise,
but has a weakness limited to the range of 10 to 1000 Hz because it has a
natural frequency in the upper and lower frequencies, which is why displacement
sensors and acceleration sensors are widely used. (If it is out of this frequency
range, an erroneous or amplified value is output.)
A sensor (transducer) is one of the components of a system that is mainly used by companies that use sensors to research, diagnose or manufacture monitoring equipment. Since the manufacturer has selected a sensor that fits a specific principle, the manufacturer has accumulated a lot of engineering grounds for this. In many cases, the level of engineering is considerably deeper than that of academia because it must be required and the reliability of the measurement needs to be verified.
Above all, this principle can be considered as the most basic sensor selection method. The reason why a displacement sensor is called a displacement sensor and an acceleration sensor is called an acceleration sensor is that each sensor generates an electrical output 'proportional to the amplitude unit'. It's because you do it. For example, since the value converted to displacement by outputting acceleration vibration with an acceleration sensor and integrating twice is not very accurate (especially when it is not a sine wave), it is better to measure acceleration vibration with an acceleration sensor, and displacement vibration It is basic to measure with a displacement sensor. However, there are cases where it is absolutely necessary to evaluate the health of a machine or the vibration of a building with the 'velocity' value, which is used as the most evaluation unit in academia and industry, so this only allows integration from the acceleration sensor once. Because the speed sensor isn't cool...
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copyright korea CBM written by BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr
