Thermography Re-certification
Certification in thermography is only valid for 5 years. This is true for all levels , and is intended to ensure that only people active in the...
ASNT Vs ISO (again)
Recently I was asked about the difference between ASNT & ISO thermography courses, so I have decided to address the issue here. ANST While...
Can I really build a thermal imaging camera with a webcam?
Can I really build a thermal imaging camera with a webcam? I recently came across someone who was convinced that they could do this, and that...
What emissivity setting should I use?
I have been asked the following question; “What emissivity setting should I enter in my camera when carrying out a survey?” Of course...
What material has the best emissivity?
Recent I was asked this “What material has the best emissivity?”. It is a tricky question to answer as first I need to figure out...
Why is emissivity different with different cameras?
Why is emissivity different with different cameras? This is difficult for people to fully understand. To be honest, emissivity in general takes...
Emissivity of a Fly
Student question “In a couple of days I have to help someone calculate the emisivity of a fly and fly lava. Can you help me with below: 2)...
Factors affecting emissivity
What factor affect the emissivity of an object? Material Non-metals, usually have a high emissivity, and are usually fairly constant over time....
Distance and spot size with thermography
How far away can we measure the temperature on an object? This really does depend on the size of the object. If it is too far away it...
Does glass have a high, or low emissivity?
I have been asked the following by a student; “Does glass have a high or low emissivity? I always assumed that it was quite low as I can...
Temperature difference
Surely if I am only measuring a temperature difference then the settings don’t really matter! I regularly meet people (including very experienced...
How wrong can my temperatures be?
How wrong can my temperatures be? I have often been asked this question by students, and it does surprise them when they find out. The accuracy...
Maximum Termperature
The person that asked me this knows why its posted here. Question; Absolute temperature is the minimum temperature , but is there a maximum temperature? Answer; This...
IR Mirrors
From a student: “Are there IR mirrors available?” Answer; Yes IR mirrors are available and can be used for many different purposes....
MSX
MSX or Multi Spectral Dynamic Imaging is a new feature available with selected Flir cameras. I have recently had the opportunity to try this...
Stephan-Boltzman’s law
Stephans Boltzmans Law If Stephan-Boltzman’s Law gives us the total amount of radiation throughout the spectrum, and our camera...
Emissivity tables
Why not to use emissivity tables! During training we often tell people that they should measure the emissivity of a material if they need...
Delta T
This blog post is in response to the following question; “Do I need a temperature difference to do thermography on a building? If so, how...
Difficult emissivity measurements
In a previous blog, I described the standard method for measuring emissivity. It can be found here http://www.thermalvision.ie/2012/01/measuring-emissivity/ Since...
Why thermocouple readings don’t compare with camera results
Question received by email, slightly edited; We are busy working with a foundry that mainly does High chrome white irons. The problem that we...
Measuring emissivity
The method of measuring emissivity here is a reference method as described in ISO 18434-1. The principle is to use a material of known emissivity...