EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: Fraser on November 24, 2024, 05:38:52 pm
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I have just become the guardian of a very nice condition NEC-AVIO TH7102WL Industrial thermal imaging camera from Circa 2005. Those who know me will be aware that I love fine engineering and I have a soft spot for the well designed and built Industrial grade thermal cameras. I would be the first to admit that many of my Industrial thermal cameras would not suit those who purchase modern budget thermal cameras from the likes of Uni-Trend, Hikmicro, Guide Sensmart and Infiray. Industrial thermal cameras can be quite large and heavy plus they often do not offer the popular video recording features of more modern consumer grade cameras and dongles. Non the less, the Industrial thermal cameras do still have their uses, even when quite old models. When you dig into the specifications of quality Industrial thermal imaging systems you realise that they are very capable beasts even if dating back to the late 1990's. Over the years we have witnessed the more expensive components within a thermal imaging system become less expensive as production methods improved and new materials were employed. the microbolometer and lens system were these two key components that needed production cost reduction for us to have the budget camera offerings that we now see. The capable noise reduction systems used in modern thermal imaging cameras is essential as the microbolometer pixel size has reduced to 12um to the detriment of signal to noise ratio. The older microbolometers were able to operate without such advanced noise reduction systems due to their better microbolometer Signal to Noise ratio. This was thanks to larger pixels and VOx technology. That is not to say that effective noise reduction systems were not needed or employed in these older technology cameras. They very much needed noise reduction algorithms to "tame" the relatively noisy microbolometers and ROIC's. Noise reduction systems are not miracle workers and "over processing" of the thermal image data remains a problem. A careful balance has to be struck between reducing image noise whilst preserving useful thermal image scene content. It can be a case of "Pretty pictures" Vs true, unadulterated, thermographic imagery of a scene. The latter may not be a s"pretty" but it contains the quality thermal data needed in some situations.
Industrial thermal imaging cameras tend to be very expensive products that used to be the preserve of companies rather than your average consumer. They were just too expensive to justify for non commercial use. There are many reasons for these cameras being very expensive, some are linked to production cost and others are due to the "Industrial" use and companies willingness to pay the price being asked. The NEC-AVIO TH7102WL will have cost something like $20K+ new so this does permit a reasonably high BoM cost with decent profit margin. We see this in the quality of the materials used in Industrial cameras and the longevity of the units and accuracy of their measurements. Some are built like a Tank and can remain fully operational despite significant abuse. The FLIR PM series Industrial cameras are a good example of such rugged build quality. The NEC-AVIO TH7100 series thermal cameras were made in Japan and a response to the Industrial camera offerings from FLIR at the time. These would have been the FLIR PM575, PM675, PM695 and the later FLIR P series cameras. NEC-AVIO did not have their own microbolometer to use in a thermal camera so they bought-in the required parts from BOEING. The microbolometer used in the TH7102WL is of the same quality as that found in military weapons systems of the time and it was heavily controlled technology. The camera has a large lebel on its underside warning owners of this fact and limitations of the cameras movements across borders. These Industrial thermal cameras were using the best microbolometer technology that could be wrestled away from the U.S. Military. No wonder they were expensive !
Well I have said enough about these Industrial thermal cameras for now. Let us see what the specifications have to say about the TH7102WL.
You will see that the camera provides full auto, partial auto and manual control of the level and span settings. this is very useful in Industrial thermography. It is also equipped with true auto focus that may be engaged upon request or set to continuous focus update mode. Such true auto focus functionality is not normally seen in budget thermal imaging cameras, though I have seen at least one dongle camera claiming true auto focus. How well it works I do not know. The thermal sensitivity figure of the expensive TH7102WL may surprise some readers as it appears high compared to NETD specifications on modern budget cameras. The sensitivity of the camera system is stated as 0.08 Celsius (80mK). Note that this is the thermal sensitivity for the whole camera and NOT the NETD of the microbolometer. It may better be thought of as MRTD which is a true indication of what a thermal imaging system can actually see in terms of temperature difference in the real world. This is where Industrial thermal imaging systems differ to consumer grade offerings.... it is not a marketing fight to show the most impressive NETD figures, but rather a true statement on the actual temperature difference sensitivity that the whole camera system will offer the user. I personally like this approach to thermal sensitivity. Note also that the TH7102WL offers three frame rates that are user selectable for differing use scenarios. Finally, note the minimum measurable temperature of Range 1. The specifications on professional thermal cameras tend to be true and accurate, rather than just a marketing teams desire to impress potential customers. This camera is designed and calibrated to provide accurate temperature measurements down to -40 Celsius. That is no mean feat.
On with the specifications.....
Temperature Range: -40 Celsius to +500 Celsius
+200 Celsius to 2000 Celsius option.
Ranges: Range 1 = -40 Celsius to +120 Celsius
Range 2 = Zero Celsius to +500 Celsius
Range 3 = +200 Celsius to +2000 Celsius (option)
Resolution: 320 x 240 VOx microbolometer pixels on UFPA
ADC resolution : 14 bits.
Temperature resolution (MRTD): 0.08 Celsius (Range 1)
Measurement Accuracy: +/-2%
Frame rate: 7.5fps, 30fps an 60fps (user selectable)
Lens : Fixed mount, motorised focus, 29 Degrees HFOV, 22 Degrees VFOV. IFOV = 1.58mrad. Supplemental lenses are available for different FOV's.
Focus: Motorised single event Auto focus and continuous Auto focus, Motorised manual focus.
Focus Range: 30cm to infinity
Filters: Spatial Filter to improve image quality.
Auto Functions: Full Auto (level/Sensitivity/Focus), Auto Focus, Auto Level and Auto Sensitivity. Manual functions also available.
Processing functions:
Spatial Filter
Level Trace (auto centre level control)
Auto gain control
Background compensation
Ambient compensation (Distance, Temperature, Humidity)
Point temperature display (Centre 1 point)
Point Emissivity correction (1 point setting)
Display functions:
Run/Freeze
Colour/Monochrome (positive & negative)
16,32,64,128,256 levels
Shine/Rainbow/Brightness/Hot Iron/Medical colour palettes
Isothermal band display (4 bands)
Zoom: Electronic x2 and x4 with Spatial filtering
User display: LCD colour viewfinder or optional LCD monitor/Remote controller.
Video output: NTSC/PAL composite video and S-Video.
Memory: Removable Compact Flash (Proprietary Radiometric and BMP file types)
External data interface : RS232 with options for HPIB & IEEE-1394a
Power source: 7.2V Li-Ion Battery (120 minutes duration) or external Futaba 7.2V power adapter (supplied).
Power consumption: 6W
Case material & sealing: Grey painted aluminium alloy with rubber seals and buffers. Sealed to IP54 (dust proof and splash proof)
Shock& Vibration resistance: Shock: 30G, Vibration 3G (IEC68-2-29)
Dimensions: 97mm(W) x 110mm(H) x 169mm(D)
Weight: 1.6Kg
And now some pictures of the TH7102WL camera "as received" yesterday. It is in good condition but I will still carry out a full service and some restoration work on the camera. It was originally purchased by a company working in the Maritime theatre of operations and has survived the salt air well.
Fraser
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The camera came in a hard case with most of its original accessories, which is nice. It also had its calibration check certificate with it. This was carried out by METRUM who were the UK Agent for NEC-AVIO thermal cameras in the UK. They sadly shut down some years ago. NEC-AVIO is not well known in the UK and tended to specialise in selling to the Asian markets. They make some great quality kit :-+ but sadly somewhat rare on the UK secondary market.
For anyone wondering, the Li-Ion battery packs that this camera uses are NOT proprietary :-+ They are JVC camcorder battery packs that are commonly available and inexpensive.
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The Remote controller for the TH7102WL camera. This unit can control all functions of the camera via an umbilical cable. Fortunately I already had this remote control in my inventory.
I like these sorts of accessories as they can add to the versatility of a thermal camera and you do not need a PC or software to control the unit remotely :-+
The remote controller provides the control keypad and an LCD display that is fed with the S-Video signal from the camera. Data communications between the remote controller and the camera is via RS-232. There is the option for PC control of the camera via the same RS-232 port if desired and NEC-AVIO provide the PC software for this.
Fraser