Who are the electrical inspectors
Since IR cameras work far above visible light, there are sometimes amazing effects. "Long waves" with 7 ... 13 µm are currently standard. They are less sensitive to reflections from short-wave radiators (sun) and are therefore ideal for inspections outdoors. The sun is problematic because it leads “IR laypeople” to make mistakes. Important! The camera measures surface radiation. One can easily through smoke, but nowhere to look in or through. Exceptions are foils, which are often used as inexpensive IR windows. Unfortunately, it has so far been impossible to look through plexiglass covers or glass. They are opaque from ~ 2 µm (the manufacturers of IR cameras work on sensors that work in this area). Faults in encapsulated systems, distributions, switches, etc. often appear on the housing or are visible at the outlets. It takes some practice here.
To practice an infrared inspection
A clamp meter should not be missing next to the camera. In the case of high and medium voltage systems, the instruments may have to be consulted. Reliable information can only be obtained when electricity flows. In my experience, there is a maximum of 5 ... 15 minutes left after switching off a system. Actionism is rarely necessary when locating a “hot spot”. After all, the system has usually been running like this for a long time. Contactors, chokes, power packs, resistors, but also cables and terminals with high loads are operationally warm (measure current if necessary). Bare metal surfaces have very low emissivity and, depending on the degree of soiling and wear, strongly fluctuating emissivity and regularly show temperatures that are far too low in the thermal image. Busbars, bare metal terminals and cable lugs are difficult objects. Where they are close together, they shine and look noticeably warm (cavity radiator effect), but are hardly warmer than the bare parts. Bare metal surfaces can look cold in the IR image, but in reality they are critically heated (left image).
To speed up the inspection, many thermographers use an isotherm in the image, which highlights areas above an adjustable threshold temperature in color. For this purpose, an acoustic alarm can be triggered on some devices. It is advisable to display the IR image in grayscale with a transparent isotherm in order to still recognize the structure underneath (bottom left image). The method is particularly suitable for systems without Plexiglass covers.
Standard for IR (bolometer) cameras are handy, uncooled, long wave cameras with FPA chips (Focal Plane Array, 7-13 µm, 30-50 Hz), with 20,000 - 80,000 image / measuring points (picture below right). Scanners are also available that scan the scene line by line. You need about a second for this, which speaks against freehand recordings. The resolution is 0.015 ... 0.2 ° C, with the lower value delivering significantly better images at low temperatures. The weight is 0.7 to 3 kg, the battery life depending on temperature and monitor usage 2-3 hours. The IR images are stored in the camera or on standard media. Some devices allow the parallel recording of IR image and photo as well as voice commentary for each image. All manufacturers offer report and analysis software with which the images can be edited afterwards. Wide-angle optics are very beneficial for electrical inspections.
- Are you worried about garbage?
- Is there a cure for osteomalacia
- Why do we study Shakespeare in America
- What are the most wrong directions in life
- What do you prefer to meditation
- Will weeds keep me depressed any longer
- Can we email Mother Nature?
- How can I properly remove the background
- Women's problem with me
- Clear dreams are love from God
- What are the cons of iOS 10
- What functions are today's payment gateways MISSING
- Which Indian government agencies need translators
- What are the practical areas of psychology
- Is zombie better than the walking dead
- Who is an expert in programming
- Shredded paper is a good fertilizer
- What are some of the Hawaiian industries
- Is the law a punishment for our sins?
- Why we need foreign policy analyzes
- How accurate is an M4 rifle
- How the NASA SOLAR PROBE starts
- Is government bond an asset
- Using VueJS with NodeJS