2023년 5월 24일 수요일

BISOPE series 38 Instrument level difference between Vibrometer vibrati...


BISOPE series 38- Instrument level difference between Vibrometer (vibration meter) and FFT (frequency analyzer; multi-channel vibration analyzer)

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Unlike temperature measurement, where you can select only Celsius or Fahrenheit and press a button, you need to know a lot about 'vibration' before measuring. How to select units and how far is the frequency range? What are the types of sensors and how to attach them? Also where? in which direction? Everyone should know how to measure. As a metaphor, 'knowledge is something that is easy for those who know it, unlike wisdom that is difficult even if you know it.' If you know about the vibration, it is easy to measure the selectivity of the instrument.

 

Distinct difference between vibrometer (vibrometer and frequency analyzer FFT vibration analyzer)

 

Recent vibrometers that can perform simple spectrum frequency analysis and trend storage are being sold at low prices, but in general, vibrometers do not have as precise or diverse functions as FFT (vibration frequency analyzer). Therefore, it is necessary to know the practical optimal knowledge that can identify these differences, and refer to the following.

 

item

vibrometer

Frequency analyzer (FFT, multi-channel vibration analyzer)

Appearance

output

Types and uses of instrumentation

Magnet-attached or probe-type machine surface vibration measurement, machine condition management

Select the number of simultaneous measurement channels, whether to measure FRF (resonance), machine diagnosis, long term recording (DAQ), rotor dynamics, front-end or hand held, for Labs and machine analysis

Sensor selection

-The magnet attached type is better than the probe stick type because measurement stability and high frequency are possible.

-Sensitivity modifiable instrument (high sensitivity, high impact measurement possible)

-Sensitivity modifiable instrument (high sensitivity, high impact measurement possible)

-For low frequency detection (using displacement sensor and DC sensor, or using acceleration of 500mV/g or higher)

 

-General type acceleration sensor (100mV/g)

 

-High impact acceleration sensor (10mV/g)

Unit

 

This data is very realistic and it is the result confirmed in the actual domestic industrial field, but it can be subjective and biased, so please refer to it.

 https://blog.naver.com/vs72

All copyright  korea CBM  written by BISOPE , vs72@naver.com, 070-4388-0415,  www.kCBM.kr

 

#vibration measurement, #vibration accelerometer, #sensor attachment method, #contact resonance frequency, #FFT, #vibrometer, #vibration sensor, #3 axis vibration, #frequency, #resonance, #resonance analysis, #resonance measurement, #frequency measurement, #vibration and noise education, #frequency analysis, #monitoring, #vibration measurement, #vibration diagnosis, #facility diagnosis


76 Vibrometer진동계와 FFT주파수분석기; 다채널 진동분석기의 계측기 수준 차이v2


Vibrometer(진동계)와 FFT(주파수분석기; 다채널 진동분석기)의 계측기 수준 차이

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섭씨, 화씨 만을 선택하고 버튼만 누르면 결과를 알 수 있는 온도의 측정과는 다르게 '진동(vibration)'을 측정한다는 것은 측정하기 전에 비교적 많은 것을 알고 있어야 한다. 단위는 어떻게 선택?하고 주파수 범위는 어디까지? 두고 센서의 종류와 부착방법은 어떻게? 또한 어디를? 어떤방향으로? 측정하는 지 등 모두 알고 있어야 한다. 비유하여 언급하건데 '알고 있어도 어려운 지혜와는 달리 알고 있는 사람에게는 쉬운 것이 바로 지식'이다. 진동에 대해서 알고 있다면 계측기의 선택도 측정도 쉽게 이루어 진다.


진동측정기의 분명한 차이(진동계 vibrometer와 주파수분석기 FFT vibration analyzer)

최근의 진동계로 간단한 Spectrum 주파수 분석과 Trend저장 등이 가능한 것도 저렴하게 판매되고 있지만 일반적으로 진동계는 FFT(진동 주파수분석기)처럼 정밀하거나 다양한 기능을 포함하고 있지 않다. 따라서 이러한 차이점을 확인할 수 있는 실용적인 최적의 지식을 알고 있어야 하는데 다음을 참조하도록 한다.

All copyright 한국CBM(주) written by BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr

핵심단어

#진동측정, #진동가속도계, #센서부착방법, #접촉공진주파수, #FFT, #진동계, #진동센서, #3축진동, #frequency, #resonance, #공진분석, #공진측정, #주파수측정, #진동소음교육, #주파수분석, #모니터링, #진동측정, #진동진단, #설비진단

2023년 5월 17일 수요일

BISOPE series 37 Difference between shaft vibration and casing vibratio...


BISOPE series 37- Difference between shaft vibration and casing vibration(shaft vibration monitoring, bearing housing; casing vibration monitoring)

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If a dangerous state of a rotating machine is identified in advance or the machine suddenly breaks down, production is disrupted and huge asset losses occur. Therefore, in order to check the maintenance time while looking at the status (CBM), 'monitoring' must be performed and a 'monitoring system' must be installed or operated. As a monitoring method, the vibration of the facility is measured regularly in the field and sensing is performed by installing a continuous monitoring online system. But what is 'monitoring measurement technology'? The monitoring measurement technology is also divided into two parts as above, which are 'shaft vibration and casing vibration'. As for this distinction, even among those who specialize in vibration research, if you have not experienced the general field facility management method, you may not know the exact difference. This is very common in the current industrial field, but let's look at the direct differences in monitoring measurement technology that can never be confirmed theoretically.

 

Shaft & Casing, Housing vibration monitoring (shaft displacement vibration and bearing housing vibration)

 

Vibration in a rotating machine starts when the shaft rotates and excitation force (centrifugal force) is generated. Therefore, it is best to directly measure shaft vibration (shaft vibration measurement method), but this method has technical limitations. Therefore, a method of measuring where the shaft vibration is transmitted to the bearing housing or casing is often used, and this is commonly referred to as 'bearing housing vibration' or 'casing vibration'. This difference was sorted out.


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This data is very realistic and it is the result confirmed in the actual domestic industrial field, but it can be subjective and biased, so please refer to it.

 

All copyright  korea CBM  written by BISOPE , vs72@naver.com, 070-4388-0415,  www.kCBM.kr

 

#bearing vibration, #sleeve bearing, #metal bearing defect, #journal bearing, #vibration defect, #whirl, #bearing friction, #subharmonic, #non synchronous, #transient tolerance, #vibration diagnosis, #vibration analysis, #vibration Measurement, #frequency analysis, #facility diagnosis, #vibration education, #resonance analysis, #resonance measurement, #CBM, #vibration monitoring


75 축진동과 케이싱진동의 차이점shaft vibration monitoring, bearing housing;casing vi...


축진동과 케이싱진동의 차이점

(shaft vibration monitoring, bearing housing;casing vibration monitoring)

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회전기계의 위험한 상태를 사전에 파악하거나 또는 기계가 갑자기 고장이 나면 생산량에 차질이 발생하고 막대한 자산(asset)의 손실을 가져온다. 따라서 상태를 보면서 보수시점을 확인하기(CBM) 위해서는 '모니터링'을 하여야 하고 '모니터링시스템'을 설치하거나 운영하여야한다. 모니터링하는 방법으로는 정기적으로 설비의 진동을 현장에서 측정하는 방식과 지속적으로 상시감시 온라인시스템을 설치하여 센싱을 하게 된다. 그런데 '모니터링측정기술'은 또 무엇일까? 모니터링측정기술도 위와 같이 양분하여 구분하고 있는데 바로 ‘축진동과 케이싱진동’이다. 이 것의 구분은 진동을 전문적으로 연구하는 사람 중에서도 보편적인 현장의 설비관리방법을 경험하지 못하였으면 정확히 그 차이를 알지 못할 수 있다. 이 것은 현재 산업현장에서는 아주 보편적이지만 이론적으로는 절대로 확인할 수 없는 모니터링 측정기술에 대한 직접적인 차이점에 대해 살펴보기로 한다.

All copyright 한국CBM(주) written by BISOPE , vs72@naver.com, 070-4388-0415, www.kCBM.kr

관련 Tag

#모니터링, #CMS, #VMS, #온라인 모니터링시스템, #진동모니터링, #축진동 모니터링, #진동센서, #피에조센서, #진동교육, #설비진단교육, #위험속도, #공진분석, #진동진단, #진동측정, #3축진동


2023년 5월 3일 수요일

BISOPE series 36 Vibration problems of sleeve bearings journal bearings...



BISOPE series 36- Vibration problems of sleeve bearings (journal bearings, metal bearings)-3-excessive tolerance

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Among the defects of the journal bearing, if the tolerance between the bearing and the shaft is large or the margin is large, it is not very different from the mechanical looseness phenomenon of vibration diagnosis. Since the bearing is not subjected to strong oil pressure, it is regularly cured at a frequency related to the number of revolutions. In addition, when most of the relaxation occurs, the space between the bearing and the shaft is large, so it is not related to the pulsation of oil (Whirl), and in gradually severe cases, it is naturally accompanied by friction (Rub). Therefore, the procedure of accurately measuring and assembling sleeve bearing tolerances requires deep attention and is one of the tasks performed by highly experienced maintenance personnel.

  

Excessive clearance of sleeve bearings

 

If the tolerance is excessive, the following vibration frequency characteristics are obtained......................

https://blog.naver.com/vs72

 All copyright  korea CBM  written by BISOPE , vs72@naver.com, 070-4388-0415,  www.kCBM.kr