Condition monitoring in vibration measurement

To achieve maximum machine availability requires continuous condition monitoring. Condition monitoring detects whether machine components might fail prematurely due to wear or are undergoing damage by vibrations. Vibration analysis enables predictive, managed maintenance. However, reliable condition monitoring is usually not easy to implement in machines. Roller bearings, plain bearings and gears require monitoring. Any adverse effects then need filtering out. This requires suitably powerful sensor technology, vibration measurement technology and evaluation software. Monitoring also needs to be tailored to the specific machinery.

Condition monitoring for different applications

• Monitoring of machinery to provide maximum plant availability
• Condition monitoring of roller and plain bearings
• Turbine and generator monitoring
• Test stands for pumps
• Test stands for gear boxes and drives

Monitoring machine components using vibration measurement technology

Acquiring and evaluating vibrations require powerful measurement technology. The measuring device Expert Vibro was specially developed to monitor rotating machinery and to perform vibration tasks.

Autonomous local operation: Expert Vibro is very powerful and can be operated as a stand-alone local device due to its internal storage capability. The sensor signals are acquired via 4, 8, 12 or 16 synchronous measuring channels with sampling rates of up to 50kHz per channel.

Analysis and monitoring: The measurement technology records speeds and shaft displacement, compresses data into meaningful characteristic values and evaluates the data online. Predefined limit values are monitored online and digital outputs can be switched in milliseconds when these are exceeded.

Powerful signal processing: In complex machine systems, a variety of components may be responsible for unwanted vibrations. Frequency analysis and phase determination enable detailed diagnosis, precise identification of individual components and a differentiated view of suspect vibrations.

Software for vibration analysis: ProfiSignal is the software for data acquisition, analysis, visualisation and automation. The additional option "Vibro" provides special visualisations for vibration measurement analyses such as Bode diagrams, frequency spectrums (FFT), envelope curve spectrums and cascade diagrams. The ProfiSignal Web software enables measurement data to be acquired locally and accessed via any device regardless of location.

Practical example of conveyor belt monitoring

The rollers on the carriers of a baggage handling system are subject to high stresses from continuous loads. However, roller wear and tear and failure rates differ greatly. To prevent breakdowns of baggage systems, each carrier is individually monitored by two acceleration sensors.

The enormous volume of sensor data acquired is first pre-selected and compressed within the measurement technology and then transmitted to a controller via OPC UA HA. Evaluation routines have been created, tested and implemented on site by Delphin’s applications development team. Wear and tear of the rollers is now being continuously monitored enabling maintenance to take place when required.

Practical example of ventilator monitoring

In the production facilities of a pharmaceutical company, large ventilators ensure that the required temperature ranges are maintained. To avoid ventilator failure and disruptions during operations, acceleration sensors monitor the ventilator drive bearings. Their condition is then continuously analysed and the degree of wear determined. Continuous fan monitoring ensures that each bearing can be promptly replaced depending on its degree of wear.

Limit values are specified for the drive bearings with a (non-critical) pre-alert being triggered in the event of increased wear. Data is pre-processed and compressed before being transferred to a central ERP system via an ODBC interface (Open Database Connectivity). In the event of a serious fault, a main alarm is triggered and the ventilator automatically stopped to prevent it being damaged.

Maximum flexibility for condition monitoring

The Expert Vibro measuring instrument has been developed to give maximum flexibility. It can record data from different sensor types and provide detailed analyses. It can also combine vibration and process data.

In addition to acceleration sensors, the following sensors can also be incorporated: temperature, eddy current, structure-borne noise, power, pressure, flow and measuring microphones according to the IEPE standard (Integrated Electronics Piezo Electric). Data acquisition at 24-bit resolution and very high sampling rates enable measured vibration and process data to be synchronously recorded and evaluated within a single system.

Tailoring vibration measurement technology to requirements

Modifications may be necessary to achieve condition monitoring for specific machinery and plant. In practice, sensor technology often needs tailoring to the specific installation. Connections to existing databases and to control systems are also usually required.

Delphin's measurement technology provides the necessary interfaces such as OPC UA, Modbus RTU, Modbus TCP, PROFIBUS or CAN. OPC UA (HA) and ODBC are provided via software. Delphin's applications development team provides the necessary support to ensure that the measurement technology can be tailored as quickly and easily as possible to a specific installation.

Powerful yet compact measurement technology

Condition monitoring using vibration measurement technology requires a particularly powerful measuring system. It not only needs to be capable of acquiring data but also of quickly processing enormous volumes of data, pre-processing data online, calculating characteristic values, applying special analysis methods such as phase angle determination, evaluating high-resolution frequency spectrums (FFT) and real-time alarm processing when limit and threshold values have been exceeded. Very compact dimensions, such as in the Expert Vibro measuring instrument (210 x 80 x 125 mm), means an additional control cabinet is generally not required.