دوربین ترموگرافی

مبانی فیزیکی ترموگرافی مادون قرمز

ترموگرافی مادون قرمز (Infrared Thermography) مبتنی بر پدیده ای فیزیکی است که بیان می دارد هر جسمی با دمای بالاتر از صفر مطلق (۲۷۳٫۱۵- درجه سانتی گراد) تابش های الکترومغناطیسی از خود ساطع می کند. رابطه ی واضحی بین سطح یک جسم و شدت و ترکیب طیف ساطع شده از آن وجود دارد. با اندازه گیری شدت تابش های بدست آمده از یک جسم، دمای جسم به روشی غیر تماسی قابل تشخیص است.

محدوده ی طیف الکترومغناطیسی

تابش فروسرخ قسمتی از طیف امواج الکترومغناطیسی است که بلافاصله پس از نور قرمز با طول موج تقریبی ۷۶۰ نانومتر قرار دارد و به سمت طول موج های بالاتر (تا حدود ۱ میلی متر) گسترش می یابد. برای اندازه گیری دما، طول موج های تا ۲۰ میکرون از اهمیت بالایی برخوردار هستند.

۱۲ نکته که قبل از خرید دوربین ترموگرافی باید بدانید

خرید یک دوربین مادون قرمز یک تعهد بزرگ است. حتی با وجود کاهش قیمت چشمگیر این دوربین ها در طول چند سال گذشته، شما می خواهید مطمئن شوید که برای پولتان بهترین گزینه را انتخاب می کنید و دوربین منتخب شما در طولانی مدت به شما خدمت خواهد کرد. برای برخی فاکتور هزینه نقش اصلی را در انتخاب بازی می کند، در حالی که برای دیگران، سخت افزار و نرم افزار های کلیدی بیشتر مهم هستند. در هر صورت، هر دوربینی را که انتخاب کنید باید کیفیت و قابلیت اطمینان بودن و همچنین پشتیبانی فنی و خدمات مناسبی را به شما ارائه نماید.

انتخاب های زیادی از مدل های “نشانه بگیر و عکس بگیر” گرفته تا مدل های تخصصی HD در مقابل شما قرار دارد. پیدا کردن بهترین انتخاب برای نیازهای شما دلهره آور به نظر می رسد. با مطالعه ی ۱۲ نکته ای که در پی می آید، می توانید به درک صحیحی از چیزی که میخواهید اندازه گیری کنید و محیطی که قرار است در آن اندازه گیری ها را انجام دهید می رسید.

۱) با توجه به بودجه خود یک دوربین حرارتی با بالاترین رزولوشن دتکتور/کیفیت تصویر بخرید

اکثر دوربین های مادون قرمز دارای پیکسل های کمتری در مقایسه با دوربین های طیف مرئی هستند بنابراین حتما به رزولوشن دتکتور توجه نمایید. هرچه رزولوشن دتکتور بیشتر باشد، دوربین می تواند اهداف کوچکتری را در فواصل دورتری بررسی نماید و تصاویر واضح تری را از آن ها بدست دهد.

همچنین مراقب تفاوت بین رزولوشن دتکتور و رزولوشن صفحه نمایش باشید. برخی تولید کنندگان تبلیغ زیادی را در مورد رزولوشن صفحه نمایش LCD انجام می دهند، در حالی که رزولوشن پایین دتکتور دوربین های خود را مخفی می کنند. در هر حال بخاطر داشته باشید که رزولوشن دتکتور دارای اهمیت بسیار بیشتری است زیرا کیفیت تصاویر ترموگرافی همیشه توسط رزولوشن دتکتور تعیین می شود.

Optical Fluorescence Microscope

Optical Fluorescence Microscope
Fluorescence microscope is a technique used by fluoroscopic fluorescence radiation created by fluorophors. Fluorophore is a kind of fluorescence pigment used to label proteins, tissues and cells to see them using a fluorescence microscope. The fluorophore absorbs the light at a particular wavelength (arousal), and then reflects this energy in a different optical wavelength (emission wavelength).
Fluorescence microscopes can have a simple system like epifluorescent microscopes, or have a complex structure like a multi-focal or multi-photon microscope. This simple and complex microscope follows the same principles. An excitation energy is used to irradiate a specimen. Then this energy is emitted by a different wavelength sample. The radiation emitted, although weak, can be measured. The excitation and emission wavelengths are not the same as the wavelengths, so the overall opacity can be increased with optical filters.
The following figure shows a real fluorescent image. The specimen is excited by a low-wavelength source (350-350 nm) and then emits a reflection wavelength that is longer than the astronomical wavelength. Images like this can not be seen without the use of advanced light filtering techniques. Fluorescent proteins in the samples produce outstanding colors.
Optical Fluorescence Microscope INFORTEX COMPANY

Figure 8) Fluorescence image of micro-spheres
Fluorescent microscopes are very similar to dark field microscopes and bright fields. With the difference in fluorescence microscopy, sophisticated filtering techniques are used to narrow the narrow band of light. The three key filters required for fluorescence microscopy include an excitation filter, two-color, and emission.
Aperture filter: This filter is placed in the exposure pathway to the sample. This filters all wavelengths of the light source, except the wavelengths that cause the fluorophore excitation or the underlying sample to be evaluated.
Double-colored filter: With a 45 degree angle between the evaporation filter and the exhaust filter. This filter reflects the rays of arousal toward the fluorophore and passes through the reflection beams to reach the sensor.
Exhaust Filter: This filter is placed in the sample path of the sample. This piece filters the entire reflection rays of the sample and allows it to pass only to the reflected beams.
Optical Fluorescence Microscope INFORTEX COMPANY

Figure 9: Configuration of optical filters used in fluorescence microscopy

Phase Optical Microscope

Phase Optical Microscope - Contrast
This microscopic technique increases the contrast of transparent specimens, living cells, microorganisms, and other specimens. The main advantage of the contrast phase technique is that living cells and tissues do not need to be lost, stained, painted or prepared in any way, and can be examined with their normal state. Dynamic recording and analysis of complex biological processes is very easy with the phase contrast microscope.
A phase contrast image usually contains a background with a natural color, surrounded by variable contrast created by the effect of the sample on the light. The two most commonly used effects in the contrast phase images are shadow patterns and light halo. This occurs when the focal length of the Mordaj-Infinity is not consistent with the sample and the background. Although these effects are common in the contrast phase images, they reduce the resolution of the detail. Specific object lenses, called apodizing phase contrast objects, are used to reduce this effect.
Phase Optical Microscope - Contrast | Polaritc Company

Figure 6) Contrast Picture of a Napkin Napkin
The contrast phase technique translates very little changes in the wave phase to discriminating domain variations. A bright field microscope can be converted into a contrast phase microscope by adding two pieces. These two pieces are:
Fuzzy page: By placing on the back of the object's lens, this page selectively changes the phase and range of the rays passing through the sample.
Condenser ring: A black flat plate has a transparent ring placed in the front of the focal plane.
Phase Optical Microscope - Contrast | INFORTEX COMPANY

Figure 7 Optical path microscope Contrast Phase

Optical dark microscope
The dark field exposure is a technique that removes scattered light from the sample in the image. So the image obtained by this microscopic technique, unlike the bright background, is a typical image on a dark background. The primary purpose of imaging by this technique is to increase the contrast of the colored specimens.
Common images of dark field microscopes include a bright example in a dark background. This method is suitable for capturing non-colored samples or images that require contrast enhancement. The advantage of this method is that living specimens do not need to stain and can remain nasty. Also, due to live cellular analysis, it is possible to obtain more qualitative results in this method.
Optical dark microscope INFORTEX COMPANY

Figure 2) Illuminating the dark background of the tissue paper
 

Figure 3) Optical path of the dark field microscope

Optical path A dark field microscope is usually applied vertically. This path consists of three key pieces:
Light source: This light opens to the compacting block by colliding with the blocking disc, and only one loop hits the sample.
Density Lens: The light passes through the circle that passes through the disk and builds it on the focal sample.
Object Lens: Displays scattered light from the specimen. It should be noted that the light passed through the specimen, if not scattered, is not collected by this lens.

Optical microscope bright field

Optical microscope bright field
The bright field exposure, which is the result of placing a dark object on a dark background, is the simplest optical microscopic technique. In the bright field exposure, the light source is placed below the sample. Then the light passes through the sample and is observed by the objective lens (objective) and the sensor located above the sample. The simplicity of the clear background method is the main reason for the popularity of this microscopic method.
Common images The bright background microscopes include a dark sample in a bright background. The more points on the sample are darker, the more light they will be absorbed. For example, plant cells in the nucleus and central regions where the cellular materials are denser appear darker and appear more rigid in the cytoplasm of the ribosome, the endoplasmic network, and other intracellular components. Animal cells without coloring, which ultimately lead to the death of living cells, are hardly imaging by this method.
Optical microscope bright background | INFORTEX COMPANY

Figure 1) Illuminated background light on the tissue paper
In the optical path, there is a clear field microscope with four key components:
Optical source: Usually a broadband optical source such as halogen quartz lamp is used for exposure to the sub-specimen.
Density Lens: Focuses light from an optical source on the sample.
Object Lens: Collect light from the sample and increase the visibility of detail by magnifying.
Eye / Camera: View or capture an image
The limitations of this microscopic method include very poor image contrast for cellular or biological samples, low optical resolution due to optical constraints and the need for colored specimens before viewing or imaging. Although the simplicity of this technique is a great benefit for the first observation of anonymous samples.