In the hustle and bustle of our daily working lives many of us neglect the simple diagnostic solutions in favour of more complex strategies and expensive diagnostic equipment. In some cases the use of expensive instrumentation is mandated, but more often than not a simple approach to performance monitoring can be employed.
Effective performance monitoring indicators not only convey instantly recognizable information, but are simultaneously interactive with the operator. Simple solutions to performance monitoring employ the use of what I call Auto Recognition Techniques or ARTs to assist the operator in rapidly assessing the machine’s running condition or changes to running conditions.
ARTs addressed in this article are passive in nature; no intervention or articulation is required by the operator to assess performance condition. This article presents some simple ART solutions and cites examples for machine vibration, air exchange, filtration, fill levels and temperature.

Machine vibration.
It is a fact that excessive vibration is a machine "killer". Combating excessive vibration often requires ‘vibration analysis’ to be performed (using vibration analysing instrumentation).
The machine is torqued down and aligned to within acceptable limits of vibration. A predictive maintenance program can then be set up which regularly analyses, on a calendar or run time basis, the machine’s vibration signature.
Providing the machine is set up correctly, and no external factors change that set up, the machine’s signature will stay within specification. However, if a condition occurs to change a set up (for example, machine overload), excessive vibration may be initiated and could occur in between PdM checks, placing the machine in a potential failure condition. The operator could reduce a potential problem from the machine’s pitch (sound) change, but it is difficult to differentiate conclusively actual versus previous conditions without a visual indication of change. A simple ART used for this type of situation is the Vibration Line Marker technique. When the machine is initially set up, all critical torqued bolts (see figure) and positioned parts are marked with a painted yellow line. If excessive vibration occurs causing the parts to misalign or move, this movement and its severity will be immediately visually displayed to the operator.

Air exchange.
Controlled environments within buildings are often placed under the care of the maintenance department. These controlled environments (e.g., hospital laboratories, computer rooms, etc.) require constant air exchange. A simple ART that can be employed in these instances is an air streamer. A yellow or red ribbon is tied to the air-out vent and the constant air flow will cause the ribbon to ‘dance,’ allowing rapid visual checks of air flow existence.

Filtration.
Use of air filters to filter external air into a machine usually employ a filter placed inside the machine next to a louvered window. Checking filter effectiveness requires the machine or cabinet to be physically opened. Using the simple ART methodology, the air filter is removed from the inside and placed on the outside of the louvered window. It is a simple operation to perform and all personnel can become ’filter checkers.’

Fill levels.
Reservoirs require filling. A reservoir is always engineered to have a ’lo’ level and a ’hi’ level position. The difference between the two levels is what I refer to as the Safe Operating Window.
An ART solution dictates that both hi and lo levels be clearly marked with large position markers physically and permanently attached to the reservoir.

Temperature.
My previous column on performance monitoring talked about a temperature performance indicator. There are instances where it is not practical to use a gauge. In these cases a simple ART would employ a temperature crayon marker. For example, a constantly lubricated bearing is not to exceed 150F in temperature; in this case the bearing housing is marked with a 150F temperature crayon. (The words ‘help’ or ’fail’ can also be written on the housing.) Up to 150F the crayon is not visible, however, if it exceeds 150F the written words appear, prompting the operator to take action.