Machine Condition Monitoring Technical Library

Publish Date: Jul 19, 2017 | 22 Ratings | 3.55 out of 5 | Print | Submit your review


Machine condition monitoring is the process of monitoring the condition of a machine with the intent to predict mechanical wear and failure. Vibration, noise, and temperature measurements are often used as key indicators of the state of the machine. Trends in the data provide health information about the machine and help detect machine faults early, which prevents unexpected failure and costly repair.

Table of Contents

  1. Contents
  2. Understanding Machine Condition Monitoring
  3. Sensors and Signals
  4. Signal Processing and Machine Condition Monitoring Software
  5. Signal Conditioning and Machine Condition Monitoring Hardware
  6. Turnkey Solutions
  7. Case Studies

1. Contents

Understanding Machine Condition Monitoring

Discover how machine condition monitoring works.


Sensors and Signals

Examine the physical signals and sensors used for machine condition monitoring.


Signal Processing and Machine Condition Monitoring Software

Learn about the software used for machine condition monitoring.


Signal Conditioning and Machine Condition Monitoring Hardware

Learn about the hardware used for machine condition monitoring.


Turnkey Solutions

Explore ready-to-run solutions for machine condition monitoring.


Case Studies

View customized solutions for machine condition monitoring.

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2. Understanding Machine Condition Monitoring


Discover why machine monitoring is important for increasing the life of your machinery and the efficiency of your plant. 

Featured Resource
NI Machine Condition Monitoring Portal

Machine condition monitoring is important because it provides information about the health of a machine. You can use this information to detect warning signs early and help your organization stop unscheduled outages, optimize machine performance, and reduce repair time and maintenance costs. Figure 1 shows a typical machine failure example and the warning signs.

Figure 1. The warning signs of machine failure: Using a machine condition monitoring system, you can detect failure signs months before repair is required, allowing for proper maintenance scheduling and shutdown.

As shown in Figure 1, vibrations are the first warning sign that a machine is prone to failure. This warning sign can provide three months of lead time before the actual failure date. Monitoring this data with vibration analysis hardware and software helps you predict this failure early and schedule proper maintenance. 

Types of Machine Condition Monitoring

Each of the five main varieties of machine condition monitoring serves a different role.

  • Route-Based Monitoring
    Route-based monitoring involves a technician recording data intermittently with a handheld instrument. This data is then used for trending to determine if more advanced analysis is needed.
  • Portable Machine Diagnostics
    Portable machine diagnostics is the process of using portable equipment to monitor the health of machinery. Sensors are typically permanently attached to a machine and portable data acquisition equipment is used to read the data.
  • Factory Assurance Test
    Factory assurance test is used to verify that a finished product meets its design specifications and to determine possible failure modes of the device. 
  • Online Machine Monitoring
    Online machine monitoring is the process of monitoring equipment as it runs. Data is acquired by an embedded device and transmitted to a main server for data analysis and maintenance scheduling. 
  • Online Machine Protection
    Online machine protection is the process of actively monitoring equipment as it runs. Data is acquired and analyzed by an embedded device. Limit settings can then be used to control turning on and off machinery.

Application Areas

Condition monitoring is used in a wide variety of industries. The following is a brief overview of how it works in just a few of them. Certainly condition monitoring can play an important role in any machine with vibrations.

Wind Energy

To be competitive in the energy market, wind turbines must be operated as cheaply as possible. Maintenance costs for their often remote locations are typically quite high, so route-based monitoring or portable diagnostics systems often don't make sense.  

Online machine monitoring is often used to monitor wind turbines online from a central location. Technicians can then be deployed to the remote wind farm locations only when maintenance is actually needed.

Additionally, as companies design larger and more efficient direct-drive turbines, the need for more advanced factory assurance tests becomes increasingly important. Large test cells will need to be built that can monitor turbine designs for up to weeks at a time to verify new multimegawatt designs.

Wind Energy Resources
National Instruments Wind Turbine Condition Monitoring Portal
Wind Turbine Condition Monitoring

Oil and Gas

As the cost of reaching oil and gas reserves increases, reducing the operating and maintenance costs of oil and gas assets grows increasingly important. Pumps and drills are often in remote locations where technician expenses are high.

Using online condition monitoring techniques, you can monitor pumps, wells, and refineries from a central location and only deploy maintenance personnel when necessary, saving operating and maintenance costs.

The oil and gas industry is also increasingly under pressure for improved safety and oversight. Condition monitoring offers the opportunity to discover possible defects weeks before a technician may find them, and it provides advantages over performing maintenance at only manufacturer-recommended intervals, which may not be early enough to prevent a catastrophic failure.

Oil and Gas Resources
National Instruments Oil and Gas Condition Monitoring Portal

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3. Sensors and Signals


Learn about the different sensors used in machine monitoring. 

Featured Resource
Sensor Fundamentals Tutorials

Machine condition monitoring is dominated by three different types of sensors: accelerometers, tachometers, and proximity probes. Accelerometers are used to monitor the vibrations of a machine. Tachometers are used to determine the rotational speed of a shaft to provide phase information for the vibration data. Proximity probes are used to monitor the movement of a shaft.


Accelerometers are transducers for measuring the dynamic acceleration of a physical device. They are important to machine monitoring because they monitor system vibrations. You can use these vibrations to predict the life cycles of parts and to detect faults in machinery. Piezoelectric accelerometers are the most common.

Proximity Probes

A proximity probe is a transducer for measuring the displacement of a physical device. They are important to machine monitoring because they monitor the movement of a rotating shaft. Proximity probes are usually found in 90-degree offset pairs to map an X-Y plot of the shaft movement. Then you can detect imperfections such as misalignment of the shaft, faulty bearings, or other external factors preventing perfect rotation. 


A tachometer is a transducer for measuring the rotational speed of a physical device. They are important to machine monitoring because they provide rotational speed as well as phase information, so you can match frequency components to shaft speed and position. 

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4. Signal Processing and Machine Condition Monitoring Software


Discover how orbit plots, waterfall plots, and order analysis can help you effectively monitor your machine.


The Sound and Vibration Measurement Suite contains general-purpose NI LabVIEW measurement analysis and determinism functions with analysis and displays for applications involving vibration analysis and rotating machinery. With this software, you can calculate overall vibration level (RMS, peak, crest factor); integrate from acceleration to velocity or displacement; operate online order analysis such as order tracking, order extraction, and order spectra computation; process digital and analog tachometer signals; apply limit testing on time data or power spectra; and draw spectral maps, color maps, waterfall plots, cascade plots, Bode plots, polar plots, orbit plots, time base plots, shaft centerline plots, and Campbell (intensity) plots.


Example Code


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5. Signal Conditioning and Machine Condition Monitoring Hardware


Examine the different platforms and hardware I/O available for machine monitoring.

Most machine condition monitoring sensors require some form of signal conditioning to optimally function, such as excitation power to an accelerometer. Filtering on the signal is also common, to reduce both line noise and unwanted frequency ranges. National Instruments dynamic signal acquisition products offer all of the required and recommended signal conditioning for accelerometers and microphones.



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6. Turnkey Solutions


Learn about ready-to-run machine monitoring systems.

Shorten your time to market by purchasing a complete, prebuilt system from a National Instruments partner.

  • FAG Industrial Systems
    FAG ProCheck is a latest-generation, intelligent online monitoring system that can measure, record, and analyze data independently from other systems. Because of its flexible configuration options, it can be used to monitor machines and components in nearly all industry sectors.
  • vibDAQ by Cal-Bay
    These vibration diagnostic systems are available in a variety of configurations from four to 56 channels. Standard machine vibration diagnostic tools include order tracking, plots, transients, and balancing applications.
  • Dynalco
    RTonline system based on LabVIEW for reciprocating compressor monitoring.

These are just a few of the many partners National Instruments works with around the world to provide its customers with complete ready-to-run solutions. For a complete list of NI machine condition monitoring partners, visit the NI Sound and Vibration Solution Partners page.

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7. Case Studies


Explore custom machine monitoring systems.

These solutions highlight customers who successfully implemented National Instruments machine monitoring systems:

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