Often in our classes, we are asked “what are the most interesting thermal images that you’ve taken?” I always think back to a time that I was asked to look at a hot air balloon by the pilot of the Mayflower balloon.

It was a great afternoon during Canton, Ohio’s “Hall of Fame” week, and every year there is a balloon festival. I thought, “This year I’ll bring my infrared camera and try to get some good images.” At one point the pilot of the Mayflower balloon walked by and saw my thermal imager and it piqued his interest.

Solo porque una cámara termográfica posea un rango térmico que va desde temperaturas muy bajas hasta temperaturas muy altas, no significa que la cámara pueda soportar dichas temperaturas en el ambiente donde trabaja. Se debe distinguir entre el rango térmico de la cámara y las condiciones de temperatura ambientales donde podría funcionar. El rango térmico de la cámara se define como las temperaturas que podrían ser detectadas o medidas por la cámara infrarroja.

Energized Electric Motor Testing is an essential ingredient in any World Class maintenance program. The evaluation of acquired data should follow a set sequence. Voltage should always be evaluated first. Evaluating current is the second step. Current should be evaluated second. Current can provide a great deal of data to asset motor and driven components. From the monitoring of In-Rush start current to the modulation effects of electrical and mechanical anomalies, current is a significant parameter to monitor.

In the second part of our three-part series, we will discuss how the condensation of water vapor and vapor retardant barriers are destructive elements that can cause deterioration of materials and failure of building assemblies. There are four different physical mechanisms that can cause moisture to affect surface temperature. We will address the second two of them in this tip.

2. Moisture detection through condensing phase change

Temperature is defined as a measure of the relative hotness or coolness of a material compared to a known reference. We use relative temperature scales such as Fahrenheit and Celsius in most day-to-day temperature measurements. They are called relative because they are relative to the boiling and freezing points of water (Fahrenheit used a brine solution). That is a common reference. We also have absolute temperature scales, Kelvin, and Rankine, which are called absolute because they start at absolute zero and that is our reference, the point where molecular motion stops.

Commençons cette discussion en précisant qu’il s’agit en fait de la « température apparente » des commutateurs. Tel que discuté dans nos cours de niveau I et de niveau II, les surfaces métalliques nues sont de mauvais émetteurs, et que d’essayer de pouvoir capter leur température radiométrique précise est presque impossible. Cela dit, nous pouvons utiliser la température apparente des contacts de commutateurs pour nous donner une meilleure idée de l’importance d'un défaut dépisté.