Volume 6 Issue 2 February 2017
Many who live in cold climates are in the habit of allowing their automobile to warm up before driving. For accurate temperature measurement, one should allow sufficient time for a radiometer to equalize with ambient temperature.
When performing non-contact temperature measurements, many thermographers correct for error sources due to emissivity, reflectivity, and transmissivity. An error source that is often ignored is the temperature of the radiometer itself. Depending upon design, radiometer operating temperature can significantly affect measurement accuracy.
When performing non-contact temperature measurements, many thermographers correct for error sources due to emissivity, reflectivity, and transmissivity. An error source that is often ignored is the temperature of the radiometer itself. Depending upon design, radiometer operating temperature can significantly affect measurement accuracy.
Infraspection Institute’s annual IR/INFO conference was recently held in Orlando, FL. IR/INFO 2017 marks the 28th anniversary for the advanced training conference, technical symposium, and technology expo.
IR/INFO was attended by infrared thermographers, predictive maintenance technologists, and building inspection professionals from around the world who enjoyed four days of networking, learning, and fun in a relaxed and professional atmosphere.
IR/INFO was attended by infrared thermographers, predictive maintenance technologists, and building inspection professionals from around the world who enjoyed four days of networking, learning, and fun in a relaxed and professional atmosphere.
For over 30 years, thermographer credentials have been routinely referred to based upon an individual’s level of certification. Until now, it has been customary to issue one of three certification levels (I, II, or III) to students who have completed formal training classes dedicated to the use and application of thermal imagers. Because this practice does not consider an individual’s experience, it is impossible to determine a thermographer’s qualifications based solely upon such certification.
Lightning arrestors are a common feature in electrical distribution systems and are used to guard against voltage surges associated with lightning strikes on power or communications lines. Installed at strategic locations, lightning arrestors act as safety devices to provide a short circuit path that carries excess voltage to ground during a lightning strike.
Lightning arrestors are connected between a conductor and ground. In order to prevent a ground fault, lightning arrestors are engineered so that normal line voltage will not pass through the arrestor under normal conditions. While some lightning arrestors employ a simple spark gap, others consist of porcelain tubes that are filled with semi-conductive discs made of silicon carbide or zinc oxide. During a lightning strike, the resistance of the spark gap or oxide plates is overcome and excess energy flows to ground.
Lightning arrestors are connected between a conductor and ground. In order to prevent a ground fault, lightning arrestors are engineered so that normal line voltage will not pass through the arrestor under normal conditions. While some lightning arrestors employ a simple spark gap, others consist of porcelain tubes that are filled with semi-conductive discs made of silicon carbide or zinc oxide. During a lightning strike, the resistance of the spark gap or oxide plates is overcome and excess energy flows to ground.
If a lightning strike is sufficiently strong, lightning arrestors may be permanently damaged and begin to conduct electricity to ground full time. When this happens, the body of damaged arrestors will heat up allowing them to be detected with a thermal imager. The thermogram at right shows a typical defective lightning arrestor.
Properly functioning lightning arrestors should be uniform in temperature and close to ambient air temperature if they have not undergone recent solar loading. Individual arrestors should not have any pronounced hot spots across them. Working early in the morning, on cloudy days, or at night will help to eliminate solar loading which can hide defective arrestors. When performing your inspection, don’t forget to check grounding connections for hot spots as well.
Properly functioning lightning arrestors should be uniform in temperature and close to ambient air temperature if they have not undergone recent solar loading. Individual arrestors should not have any pronounced hot spots across them. Working early in the morning, on cloudy days, or at night will help to eliminate solar loading which can hide defective arrestors. When performing your inspection, don’t forget to check grounding connections for hot spots as well.
