Discuss about the passive and active thermography
A. Describe in your own words (not more than 250 words) the differences between passive and active thermography. List at least 2 typical applications of each technique
B. A double pane window has an inside temperature of 20C and an outside temperature of 0°C as shown in Figure Q1-B. What is the quantity of heat transferred per unit surface area through the thickness of the window?
Justify if a similar size single pane window is better that a double pane one considering the overall thermal insulation
A. Find the wavelength at which the maximum energy can be found for a blackbody at room temperature (200°C):
Give the wavenumber and frequency for the wavelength of the infrared emission?
B. Find the total emissive power of this blackbody.
C. Consider a copper emitter (with an emissivity of 0.65) at a temperature of 273 °K. What is the total power lost by this emitter if its area is 2 m2?
D. List at least 3 parameters that influence the emittance of real objects.
A. [IR Detectors]: An IR detector outputs a voltage of 150pV .During design tests, the detector current is measured as 7pA. The current is in phase with the voltage. What is the type and value of the IR detector impedance?
B. A contact lens is made of plastic with an index of refraction of 2. The lens has an outer radius of curvature of 1.5 cm and an inner radius of curvature of 2 cm. What is the focal length of the lens?
A. What is the raw file size for an image of 640 rows and 480 columns, with 24 bits per pixel? What is the final size of the image after PNG compression (assume it is 30% of the raw file size)?
B. The minimum and maximum values observed in a low-contrast 12-bit thermogram are 450 and 3500, respectively. What is the value of a pixel of observed value 2364 after applying linear stretching?
C. Suppose that we have the following IR image:
• What filter would you use to remove the impulsive noise in the fourth row of the image? What would the second row of the image be after filtering (assume 1 x 3 filter)?
• What would be the element (2,1) of the image after convolving the highpass filter mask of Figure 6.15 in LP6 with the original image?
• What would be the element (2,3) of the image after convolving the lowpass filter mask of Figure 6.20 in LP6 with the original image?
