Implementing an IR Thermography Maintenance Program

Pumps & Systems, November 2008

A successful infrared program involves planning and action. This article outlines steps that will help you implement a thermography program. 

Getting Started

Gain Support from Management

Send management a summary of what you learned in thermography training and your ideas for the next steps. Communicate what you would like in the way of support and find out how thermography performance results will be measured.

Practice Reading Thermographic Images

Aim for using the camera two to three times each week throughout the next six months to gain expertise. Plan your work, track your findings and document results from the beginning.

Meet Regularly with First Level Managers, Line Supervisors and Other Coworkers

Explain what thermography involves, demonstrate the camera, ask for  support and establish a mechanism for thermography survey requests. Set up a trophy board of thermal image discoveries to help communicate your program throughout the facility.

Integrate with Other Predictive Maintenance Efforts

Thermography is often part of a larger predictive maintenance (PdM) program. Data from several technologies, such as vibration, motor circuit analysis, airborne ultrasound and lube analysis, can be used to study the condition of a machine asset. Ideally, these technologies will work from and with the same computerized maintenance management system (CMMS) to access equipment lists and histories as well as store reports and manage work orders.

Establish Written Inspection Procedures

Written inspection procedures drive the quality of the data collected and ensure the inspection is completed safely. Key ingredients include safety, conditions required and guidance for interpreting the data.

National Fire Protection Association (NFPA) 70E requires that all personnel be educated about the risks they face when working near electrical equipment. Personal protective equipment (PPE) must also be made available to minimize the risk if an accident should occur. For thermographers, PPE generally includes flash-resistant clothing and a face shield.

As a starting point for creating your specific inspection procedures, review the industry standards that currently exist. See if your company has procedures that can be used as a guide and then start with the major electrical and mechanical applications and refine as you develop the program.

Avoid prioritizing findings based on temperature alone. Temperature measurements identify problems extremely well and may help characterize problems, but they are not the best way to determine the cause of a failing component. Your inspection procedures should address the conditions required to locate problems using thermography and other technologies needed to troubleshoot further.

Creating Inspection Routes

Begin by using existing lists of equipment from a CMMS or other inventory. Eliminate items that are not well suited for infrared measurement and focus on equipment that creates production bottlenecks. If possible, look at history to guide you; where have failures occurred in the past?

Use a database or spreadsheet to group the remaining equipment together, either by area or function, into roughly 2- to 3-hour inspection blocks.

The lists may not be up to date, so you can expect the first inspection cycle to take more time as you locate equipment, update lists, deal with access issues, etc. During your first pass, also consider taking digital photos of each piece of equipment and storing the images in the equipment database for later reference, as needed.

If thermography is new in your plant, the first few inspection cycles may yield a large number of finds. Subsequent inspections should go more smoothly. After about three cycles, reorganize the routes so they are more efficient, and add new routes and equipment into the inspection cycle as necessary. The optimum frequency of inspection will be determined by the needs of the equipment assets. As they age, are heavily loaded or are poorly maintained, inspections may become more frequent.

Frequency of inspection is based on a number of factors. The key drivers are safety, the criticality of the equipment, the expense of a failure and the frequency with which problems impact  production and/or maintenance. The last point is important enough that you should devote time to researching past failures, discussing with coworkers and reviewing plant records. Once the equipment has gone through several cycles of inspection, you may find the frequencies in Table 1 are a good target.

It is also vital to inspect all new equipment as part of the acceptance process and, for larger equipment, to establish a baseline. If equipment is damaged on arrival, inspect it as soon as possible to determine its actual condition. Some plants send their thermographers offsite to inspect new equipment before it is delivered, often finding deficiencies and problems before the equipment is accepted. When repairs or modifications are made to equipment, the CMMS must alert the thermographer to conduct a follow-up inspection; all too often a repair is not adequately made, for a variety of reasons, so do not assume everything is okay until the follow-up proves it.

Conditions may not be right for an inspection when it is scheduled. This incomplete work must be rescheduled before the next cycle, so reserve time for makeup work. You will also develop a list of equipment that needs increased monitoring until it can be repaired; many thermographers add these pieces into a weekly route until the condition changes.

Conducting Inspections

Working from a pre-inspection checklist is a good idea:

• Make sure the thermal imager is ready.
• Charge the batteries.
• Ensure that the system is within calibration by viewing a black body reference or conducting a simple "tear duct check."
• Clear the memory of previously recorded data.
• If you will be following an inspection route that has been inspected previously, upload past results to the camera so they can be compared to new findings.
• If additional equipment is required, such as a digital clamp meter for load