Technical Resources
The use of vibration sensors for the condition monitoring / predictive maintenance / reliability program of a plant's rotating machinery assets is very common today for reducing unplanned downtime, decreasing the cost of keeping spares, be able to monitor assets closely without having to utilize additional manpower and increase ROI.
Today there are a variety of vibration sensors that maintenance teams can use for this purpose, namely :-
a) Traditional vibration sensors such as velocity sensors, accelerometers and vibration transmitters
b) MEMS accelerometers
c) Wireless vibration sensors
Data from the above vibration sensors can be sent to a suitable platform such as a PLC, DAQ or dedicated online vibration monitoring system for monitoring of overall vibration trend, basic analysis of mechanical faults and if available, tracking of the machine's operating condition via an AI-learning software that can perform auto-diagnostics.
​
If you are looking to set up a vibration condition monitoring / predictive maintenance / reliability program in your plant the above would be your starting point.
​
At IMS Systems we offer customers a choice of using accelerometers, MEM accelerometer or wireless vibration sensors. We can supply the monitoring hardware i.e. the DAQ as well as the software whether software with straightforward functions or software with AI-learning features and in-built auto-diagnostics.
The easiest way to start is to ask what type of sensors you want. The reason for this is because the type of sensor you want will depend on your maintenance objectives and budget size.
​
If you take up a vibration certification course one of the first things you will learn is this basic truth - GIGO - which means Garbage In, Garbage Out. In real life application this means that reliable data is the cornerstone of an effective condition monitoring program. With this in mind we would recommend to take heed of the following :-
​
a) If you use a vibration sensor with unsuitable sensitivity, you will get less accurate data. In practice, this means you get to see vibration data that is ±15% of its true level. A suitable vibration sensor should have ±10% sensitivity. While a sensor with ±5% sensitivity is better, you would not use it as the possibility of frequent false alarms is high; such an accurate sensor is best suited for analysis use.
b) While a vibration sensor is the starting point, in reality the entire measurement chain should be considered. For example, it is increasingly common for wireless vibration sensors to be mounted with the use of magnets due to their convenience. However, unless you are mounting the sensor temporarily, the use of magnets is not recommended for permanent installation as its frequency response is not as good as when the sensor is mounted using stud mount or via an adhesive mounting pad.
c) The design of a vibration sensor is important but unfortunately, this is a topic that customers pay little attention to. Many of the newer entrants to the market particularly in the market for wireless vibration sensors do not pay as much careful attention to this - this could be due to the fact that these companies are not a sensor-centric company but a cloud platform company, hence they lack the expertise to design a proper vibration sensor. A vibration sensor that is not designed properly can lead to potential for data errors, leading to false positive alarms when the resonance is excited. A vibration expert has pointed out that :-
"Unfortunately, the first critical resonance frequency for most of these products is in the 200-300 Hz range, for sensors that sample up to 10,000, 20,000, or even 30,000 Hz and higher. The resonance falls within the first 10-20% of the sample range, and also falls squarely into a range very commonly produced by industrial pumps, compressors, and gearboxes, just to name three."
There are other factors that should be considered when setting up a condition monitoring / predictive maintenance / reliability program. Data security, the cost of data storage, cost of batteries replacement (including cost of manpower), frequency of data collection, etc.
A good condition monitoring / predictive maintenance / reliability program starts with an accurate, reliable and quality vibration sensor. Only then can you collect the right data for your software to analyse, which in turn will give you the right call for action.
​
VOLTAGE TYPE VIBRATION ACCELEROMETER
​
Vibration Sensor (Voltage Type) Selection Guide
Which type of vibration sensor should you go for? This guide does not cover the new type of MEMS and Wireless vibration sensors but the information within is still informative. Check out the information here.
​
Finally, here are 12 things to consider when you are selecting a vibration accelerometer.
Vibration Specifications Guide
Do you know what the specifications for a vibration sensor means in a datasheet? Read this guide here for information.
Mounting Guide for Vibration Sensors
Mounting a vibration sensor properly is important. If you mount the vibration sensor incorrectly you will not get good data and this will compromise your analysis. Also, different mounting methods may result in resonance. Read more here.
Vibration Measurement Locations
Where should you install your vibration sensors? Check out this guide here for explanation.
​​
Installation of Vibration Sensors
How should vibration accelerometers be installed. Read this guide here for basic installation techniques.
Vibration Piezoelectric Accelerometer Design
Today the IEPE type vibration accelerometer is still widely used despite increasing competition from wireless vibration sensors. With an MTBF of 25 years the cost of ownership of an accelerometer still beats the cost of ownership of a wireless vibration sensor. Click here for more information.
​
CURRENT TYPE VIBRATION TRANSMITTER
How to Select 4-20 mA Vibration Transmitter
The 4-20 mA vibration transmitter is used widely in process plants for the monitoring of overall vibration trend. Read this guide here for more information on how to select the right 4-20 mA vibration transmitter.
​
Application Guide for 4-20 mA Vibration Transmitter
This application guide here will review the background of machinery vibration, 4-20 mA loop sensors, and the ISO10816 standard; offer help in selecting the proper range transducer; elaborate on installation guidelines; and provide guidance with setting vibration limits.
​
Vibration Transmitter vs Vibration Switch
Vibration switches are still commonly used for cooling towers and other rotating machines. However, vibration sensors and vibration switches are not equivalent products. Newer 4-20 mA technology and products provide better protection and real time vibration monitoring information. Learn more here.
​
Cost Effective Condition Monitoring Solution
4-20 mA vibration sensors, transmitters and local displays make it simple and cost-effective to trend data on critical assets when no vibration monitoring program exists or for balance of plant machinery that is not currently being monitored. Read here to understand more.
​
Monitor Critical Machinery
Even if you aren't a vibration expert, you can monitor critical machinery vibration levels using sensors and transmitters that run on common 4-20 mA loops. How? Read the presentation here for an understanding.
​
Quick Guide to Vibration Monitoring
Read the following 1-page Quick Guides for the benefits of vibration monitoring
iii) Fan Monitoring Guide
​
Detecting Bearing Faults with Vibration
Download the helpful explanation here for detecting bearing faults. Includes photo examples of different types of bearing faults and conditions you should look out for to get to the root cause.
​
Vibration Monitoring of Cooling Towers
Vibration monitoring of cooling tower fans, gear boxes, shafts, and motors provides early warning of machine degradation and impending disaster. Click here for more information.
Vibration Monitoring of Coolers & Chillers
Read the guide here for how cooling towers, process coolers and HVAC cooling units can be monitored for vibration using the 4-20 mA analog input channels of existing PLC units.
​
Monitoring of Fans Using 4-20 mA Vibration Transmitter
Click here for guidance to determine the number and location of 4-20 mA loop powered sensors to produce a reliable vibration monitoring system to protect fans, and to interface directly with a plant Programmable Logic Controller or Distributed Control System to provide a cost-effective predictive maintenance solution.
​
What is Your Pump Health?
Pumps benefit from regular check-ups to ensure there are no underlying problems. Read here to understand how diagnostics give us an indication of the health of the pump.
​
Pump Vibration Monitoring
The overview here covers pump systems and failures, plus monitoring specifics and techniques that are designed to minimize damage, reduce downtime, and increase productivity.
​
​​