Condition Based Maintainance

The paradigm shifts from preventive or damage-dependent maintenance of machinery and equipment to condition-based maintenance (predictive) poses a difficult challenge for the industry. To succeed in cost-driven competition, this step is essential, as predictive maintenance can make more efficient use of machines and prevents unforeseen downtimes.


The most effective form of condition-based maintenance utilizes online or inline condition monitoring (CM). Due to the permanent recording of the machine condition, based on the measurement of physical quantities, increasing economic, ecological and safety pressure can be met.


The necessary technical infrastructure in the form of powerful networks, which enable the seamless integration of additional sensors, are emerging or have already been established in the wake of Industry 4.0 and Industrial Internet of Things. Furthermore, the possibilities for process modeling and data evaluation due to the high level of algorithms (e.g., deep learning) and the meanwhile cheaply available computing power allow virtually unlimited potential for accurate machine monitoring.


The last step required to make predictive maintenance a breakthrough is to provide the appropriate sensor technology. The basic prerequisites for these systems however are very strict, due to the demands of highest measurement value stability with low or no maintenance of the sensors system itself required.

Oil Condition Monitoring

In the field of oil condition monitoring (OCM), this means that the sensor can accurately determine the smallest changes as well as the absolute values of the fluid parameters, but is little affected by cross-sensitivities, aging effects and contamination. For the detection of the oil condition, the viscosity is the most important physical parameter, since it reflects the lubricating property or the introduction of foreign substances. The strong temperature dependence of the viscosity requires an exact temperature setting (better 0.1 ° C) of the measuring fluid.

Viscosity Density Cell from MicroResonant

The viscosity density cell (VDC OCM) from MicroResonant uses a low frequency resonant acoustic sensor element which can simultaneously measure density and viscosity with high accuracy at precisely controlled temperatures. The flow profile, which is generated by the sensor element used, penetrates deeply into the liquid, whereby effects of surface adhesion of fluid components are less impairing than is the case for sensors operating at higher frequencies (e.g. surface acoustic wave sensors SAW). The measuring cell is furthermore compact and easy to integrate into existing systems.