Vibration monitoring

Our expertise go from aeousties, material charaeteristies, teehnical audits to telecommunications, vibrations monitoring, etc... 

Laborelec is the Belgian laboratory for the electricity industry. It deals with measuring and studying problems arising with the production, transport and distribution of electricity to industrial and private customers. It has developed very diverse domains of expertise, such as acoustics, material characteristics, technical audits to telecommunications, vibrations monitoring, etc... 

Safety features such as overspeed trip, low-od trip, remote-solenoid trip, vibration monitor, or other special monitoring of temperature, temperature changes, and casing and rotor expansion... 

Running unbal- Preventive maintenance and operator checklist anced, vibration inspections due to worn bear-, effective vibration monitor/shutdown device ings or other mechanical problem such as product accumulation behind filter screen. ... 

Running unbal- Redesign feed distributor anced—vibration. different bowl speed (usually slower) due to uneven feeding effective vibration monitor/shutdown device Adjust feed rate to get uniform distribution ... 

IRI 1991. Vibration Monitoring Recommended Practice. IRInformation Manual 6.0.8.1.1. Industrial Risk Insurers, Hartford, CT. 

The vibration indieator as well as the taehometer should read zero. If these instruments are reading a higher number, a diseontinuity or short eireuit may exist in the eleetrieal system. Sometimes, a ground loop on the eleetronie system ean ereate a high level reading on the taehometer, RTD, or vibration monitor. 

Alignment Teehnology Vibration Monitoring and Analysis Equipment... 

It is reeommended that warning deviees be provided to eliminate as mueh human error as possible, and the set points should be eheeked earefully. As with any startup, vibrations should be monitored and reeorded. The vibration monitoring system should inelude at least one aeeelerometer to deteet any vibrations generated at gearmesh frequeney. The reeorded data should be saved to provide baseline vibration data for future referenee. 

Performanee and vibration monitoring should be properly interfaeed to aehieve a level of operation free from exeessive maintenanee and downtime and to maximize operating effieieney at every possible point in the system. 

This chapter will cover some of the more common accessory items for compressors such as the lubrication system, gears, coupling, instrumentation, vibration monitoring, and process control. The subject is broad and far-reaching. It is hoped that, for the first-time user, this discussion will be a good introduction and, for the veteran, it may offer another perspective on the subject. 

Gilstrap, Mark, Transducer Selection for Vibration Monitoring of Rotaimg Macliinery, Sound and Vibration, Vol. 18, No. 2, February 1984, pp. 22-14. 

The use of vibration analysis is not restricted to predictive maintenance. This technique is useful for diagnostic applications as well. Vibration monitoring and analysis are the primary diagnostic tools for most mechanical systems that are used to manufacture products. When used properly, vibration data provide the means to maintain optimum operating conditions and efficiency of critical plant systems. Vibration analysis can be used to evaluate fluid flow through pipes or vessels, to detect leaks, and to perform a variety of non-destmctive testing functions that improve the reliability and performance of critical plant systems. 

Leaks in process vessels and devices such as valves are a serious problem in many industries. A variation of vibration monitoring and analysis can be used to detect leakage and isolate its source. Leak-detection systems use an accelerometer attached to the exterior of a process pipe. This allows the vibration profile to be monitored in order to detect the unique frequencies generated by flow or leakage. 

Vibration data are obtained by the following procedure (1) mounting a transducer onto the machinery at various locations, typically machine housing and bearing caps, and (2) using a portable data-gathering device, referred to as a vibration monitor or analyzer, to connect to the transducer to obtain vibration readings. 

Used in conjunction with zero-to-peak (PK) terms, velocity is the best representation of the true energy generated by a machine when relative or bearing cap-data are used. (Note Most vibration monitoring programs rely on data acquired from machine housing or bearing caps.) In most cases, peak velocity values are used with vibration data between 0 and 1000 Hz. These data are acquired with microprocessor-based, frequency-domain systems. 

Most vibration monitoring programs rely on data acquired from the machine housing or bearing caps. The only exceptions are applications that require direct measurement of actual shaft displacement to obtain an accurate picture of the machine s dynamics. This section discusses the number and orientation of measurement points required to profile a machine s vibration characteristics. 

Most vibration monitoring programs rely heavily on historical vibration-level amplitude trends as their dominant analysis tool. This is a valid approach if the vibration data are normalized to remove the influence of variables, such as load, on the recorded vibration energy levels. Valid trend data provides an indication of change over time within the monitored machine. As stated in preceding sections, a change in vibration amplitude is an indication... 

Each reference or baseline data set must be clearly and completely identified. Most vibration-monitoring systems permit the addition of a label or unique identifier to any user-selected data set. This capability should be used to clearly identify each baseline data set. 

Although each of the commercially available computer-based vibration monitoring systems has unique features and formats, the information contained in this chapter is applicable to all of the systems. However, the manual provided by the vendor should be used in conjunction with this chapter to ensure proper use of the microprocessor-based data collection analyzer and the computer-based software. 

Most of the microprocessor-based vibration monitoring systems collect single-channel, steady-state data that cannot be used for all applications. Single-channel data are limited to the analysis of simple machinery that operates at relatively constant speed. 

Before computer-based systems were developed, a major limitation of vibration monitoring programs was the labor required to manage, store, retrieve, and analyze the massive amount of data generated. However, the computer-based systems in use today virtually eliminate this labor requirement. These systems automatically manage data and provide almost instant data retrieval for analysis. 

Vibration Monitoring and Analysis Station Process plant... 

Many of the microprocessor-based vibration monitoring analyzers cannot capture accurate data from low-speed machinery or machinery that generates low-frequency vibration. Specifically, some of the commercially available analyzers cannot be used where frequency components are below 600 cpm or 10 Hz. 

Electric motors are the most common source of motive power for machine-trains. As a result, more of them are evaluated using microprocessor-based vibration monitoring systems than any other driver. The vibration frequencies of the following parameters are monitored to evaluate operating condition. This information is used to establish a database. 

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