Technical Description; Operating Principle; Description Of The Functional Units - InfraTec VarioCAM User Manual

User Manual for the Thermographic System VarioCAM

3. Technical Description

3 Technical Description
3.1

Operating Principle

The VarioCAM ® hr head is a thermographic system for the long wave infrared spectral range (LWIR) of
(7.5 ... 14) µm. The lens images the object scene onto a microbolometer array at a resolution of
(640 x 480) or (384 x 288) pixels. The electrical signal of the detector arrays is further processed by the
internal electronics. The electronics contains all the functions necessary for camera operation, such as
activation of the microbolometer array, A/D conversion, offset and gain correction, defective pixel
treatment, video and PC interfaces.
Operating the system is effected via the PC interfaces, available as FireWire (IEEE 1394) and RS232*.
The use of these interfaces which are available depending on their versions of equipment requires special
software packages. You will find relevant details from Chapter 8 on, Hardware and Software Installation
®
for VarioCAM hr head*, page 5.
3.2

Description of the Functional Units

Lens
The camera lens captures the IR radiation emitted by the object in the field of view and images it on the
detector array. Field of view (FOV) and resolution/size of the measuring point (IFOV, Instantaneous Field
of View) are determined at the same distance from the focal length f of the lens used.
The following standard lenses are available:
Thermographic system of resolution (384 x 288) pixels
lens
wide-angle lens
standard lens
telephoto lens 1
telephoto lens 2
telephoto lens 3
close-up lens
close-up 0.17x
close-up 0.5x
microscopic lens 1.0x
User Manual
®
focal length (mm) min. focus (m)
12.5
25
50
75
130
focal length (mm)
for 25
for 25
-
© InfraTec GmbH 2015
hr head
0.2
0.3
2.0
2.0
5.0
focus (mm) field of view (mm²)
149
50
50
IFOV (mrad)
2.8
1.4
0.7
0.47
0.27
resolution (μm)
(80 x 60)
(27 x 20)
(13 x 10)
FOV (°)
(57 x 44)
(30 x 23)
(15 x 12)
(10 x 8)
(6 x 4)
209
70
35
5