Machine Condition Monitoring Technologies

In the first section we had an overview of the different maintenance strategies in industrial settings. We saw the selection of maintenance strategy is being driven by the business objective of the organization. We also saw that not one strategy alone is suitable for all the assets in a plant. So, the question is why we require the support of technology for condition monitoring of the machine? I started my career around sixteen years ago with a power plant, in maintenance department. At that point of time I could find many experience technicians & engineers who were having very good common sense in judging the condition of the machine. Many operators & technicians joined the plant year’s back & were looking after the O&M of same machines till that point of time. They were so much acquainted with the machine behaviour that simply by looking at the machine, by hearing the sound & by gentle touch of different components, they come to know whether everything was OK or there was some problem. ‘LLF’- (Look, Listen & Feel) was part of their daily routine. At that point of time we were very new to the industry, so, we used to be amazed with their ability of judgement by employing a method which looked so crude to us. But the reality was that they were accurate in their judgement up to a great extent. Simply by hearing they can detect the probable fault in the machine and a gentle touch was sufficient to tell the surface temperature & vibration.

 

So, the question was that whether it was art or a science? To me it was a combination of both. Earlier the operator or technicians used to work on same machine for a longer period of time, may be their complete working life on few selected machines. They were emotionally & spiritually connected with those machines. If we see at sub-atomic level, machine is like a child who can’t speak but expresses its feeling, when it’s in trouble or there is some problem. It expresses its pain in form of different process variables like vibration, temperature, sound & drop in efficiency. The operator or technician was like a mother for that machine, who instantly recognizes the fault in machine by judging these parameters (to us it was crude at that point of time) because of sub-atomic level connect with it.

 

Today the condition has changed completely. First factor of the loss of this emotional connect with the machine is the shortening of duration of work of the operator on the machine due to frequent job changes as now more opportunities of growth are available due to rapid industrialization & management job rotation philosophy. Second factor as per me is the technology itself. Now advanced condition monitoring technologies are available, so, people rely more on technology rather than developing that connect by themselves. So, different advanced condition monitoring technologies are enabling the O&M people to effectively maintain their machines by employing suitable technology as per management’s business objectives & asset classification. In the next section we will look into these different technologies, their benefits & shortcomings.