Infra red اءر م ح ل ا ت ح تة ع ش الأ= below red. Infrared light lies between ن ي ب ع ق تthe visible and microwave ف يوور ك ي م ل وا ي ئر م ل اportions of the electromagnetic spectrum. INFRA RED RADIATION - ة ع ش الأاع ع ش- اء الأر م ح ل ا ت ح تINTRODUCTION
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Infrared الحمراء تحت = األشعةbelow red.
Infrared light lies between بين the visible and تقع
microwave المرئي portions of the والميكروويفelectromagnetic spectrum.
INFRA RED RADIATION - األشعة اإلشعاع الحمراء INTRODUCTION تحت
All objects in the universe above absolute zero المطلق الصفرemit ينبعث electromagnetic radiation. الكهرومغناطيسي
Infrared wavelengths 710 موجات nm to 1
millimeter.
INFRA RED RADIATION - INTRODUCTION
The rays travel through the ether until they
encounter لقاء some medium which absorbs them & when they are absorbed HEAT is produced. يتم عندما
المنت الحرارة استيعابهاجة
INFRA RED RADIATION - INTRODUCTION
Thermo gram حراري a—مخططpicture that shows regions of different temperatures درجات
◦Near / Short Infrared - 0.75-1.4 µm in wavelength.
◦Mid Infrared - 3-8 µm.
◦Far / Long Infrared – 15-1,000 µm.
IR-A: 700 nm–1400 nm
IR-B: 1400 nm–3000 nm
IR-C: 3000 nm–1 mm
Any heated material will produce I.R.R.,
The wavelength & frequency are being determined تحديد by the temperature. درجةالحرارة
TYPES OF I.R. – GENERATORS:-
1. Non – Luminous Generator
مضيئ -- مولد غير
2. Luminous Generator مضيئة مولد
PRINCIPLE OF PRODUCTION االنتاج TYPES OF & المبدأ
GENERATORS المولدات أنواع
Reflected - انعكس
Absorbed - استوعبت
Penetration - تغلغل
Refracted - ينكسر
PHYSICAL BEHAVIOUR السلوك البدنيةOF IRR
A coil of wire االسالك من جرح wound لفائفon a cylinder أسطوانة of some insulating material عازلة such as FIRECLAY or موادPORCELAIN. الخزف أو A simple)الصلصالtype for production IRR)
Electric Currentpassed through the wires
Produces Heat
IRR are emitted from the hot wires الساخنة from the fireclay & األسالك
.which is heated by CONDUCTION الصلصال
NON – LUMINOUS (IN VISIBLE) GENERATOR - IRR
1. The emitter باعث2. The metal plate
معدنية صفيحة3. Protective wire mesh.
سلكية شبكات حماية4. Parabolic Reflector.
العاكس مكافئAdjustable Metal stand
الوقوف with المعادنscrews.
Base قاعدة / Wheel.
PARTS OF AN IRR LAMP لمبة اجزاءالحمراء تحت االشعة
Usually the coil of wire is embedded in the fireclay, then the emission of rays (IRR +Some Visible) is then entirely from the fireclay which is commonly painted السوداء .BLACK مطلي
It is placed at the FOCAL POINT االتصال of a PARABOLIC نقطة
REFLECTOR. This set-up is mainly to reflect the radiations into an approximately حوالي uniform
beam. موحدة شعاع
NON – LUMINOUS (IN VISIBLE خفية) GENERATOR - IRR
The beam does diverge انحرف somewhat due to the relatively large size of the EMITTER compared to the reflector & thus reduces the risk خطر من of HOT SPOTS يقلل
الساخنة ا لنقاط
When such lamps are switched ON, they require some time to warm-up because of the THERMAL INERTIA
الحراري الذاتي of the القصورconsiderable mass of metal & insulating material that has to be heated.
NON – LUMINOUS (IN VISIBLE) GENERATOR - IRR
Luminous generators are produced by one or
more INCANDESCENT ساطع LAMPS.
Incandescent lamp consists of a TUNGSTEN
FILAMENT شعيرة in a large التنغستن
envelop which contains INERT GAS غازمنخفض .AT LOW PRESSURE خامل ضغط
LUMINOUS (VISIBLE) - IRR
The inside part of the glass bulb is
often األحيان من كثير فيSILVERED بالفضة to provide REFLECTOR.
This lamp work on the same principle as a SIMPLE ELECTRIC
BULB. بسيطة كهربائية .لمبة
On passing electric current, it gives off a continuous spectrum in the infrared & visible region & a few UVR.
LUMINOUS (VISIBLE) - IRR
These visible & UVR radiations are absorbed by the glass & are not transmitted by the lamp.
The outside glass الزجاج ,is REDDENED خارج
absorbing some of the GREEN & BLUE محمرRAYS to give a RED VISIBLE EMISSION.
مرئية االنبعاثات األحمر
It is important to ensure that all rays fall
PERPENDICULAR عمودي to the surface in-
order to be MAXIMALLY األقصى الحدABSORBED.
The human skin absorbs 95% of the energy if the rays are PERPENDICULAR to the surface.
LUMINOUS (VISIBLE) - IRR
SHORT قصيرة IRR – 1 -3mm
LONG طويل IRR – 0.5 – 1mm
The effect will be marked
heating of the skin. Some of thisملحوظheat will be conducted more deeply into
the SUBCUTANEOUS TISSUE. النسيجالجلد تحت
The sensation to be experienced in only a COMFORTABLE WARM SENSATION
دافئ إحساس which must not مريحة
FEEL HOT. ساخن يشعر ال
PENETRATION نفوذية OF IRR
Metabolic effect: تأثير األيضIncreases metabolic activity.
Circular effect: تأثير التعميمIncreases blood flow superficially. ظاهريا
Sweating: تعرقThere is increased activity of sweat glands by reflex stimulation from heat regulating centre.
Physiological Effects of IRR:
Blood Pressure: الدم ضغطIf the heating is given to a large area of the body for a prolonged period, there will be FALL in B.P.
Pigmentation: اصطباغExcessive & prolonged IRR application can cause the destruction of ERYTHROCYTES, الكريات تدمير PIGMENTS إطالق releasing الحمراء causing brown discoloration of & أصباغskin.