Methods for measuring LED junction temperature and thermal resistance generally include: infrared micro-imager method, spectroscopy method, electrical parameter method, photothermal resistance scanning method, and the like. The surface temperature of the LED chip is measured by an infrared temperature measuring microscope or a miniature thermocouple as the junction temperature of the LED, and the accuracy is insufficient. Luminous intensity detection Light intensity, that is, the intensity of light, refers to the amount of light emitted at a certain angle. Due to the concentrated light of the LED, the inverse square law is not applicable in the close range. The CIE127 standard specifies two measurement averaging methods: measurement condition A (far field condition) and measurement condition B (near field condition) for the measurement of light intensity. In the case of light intensity, the detector area of ​​both conditions is 1 cm 2 . Normally, the luminous intensity is measured using standard condition B. Luminous flux and efficacy detection Luminous flux is the sum of the amount of light emitted by the source, ie the amount of illumination. The detection methods mainly include the following two types: (1) Integration method. The standard lamp and the lamp to be tested are sequentially ignited in the integrating sphere, and their readings in the photoelectric converter are recorded as Es and ED, respectively. The standard lamp flux is known as s, then the luminous flux of the lamp under test is D = EDs / Es. The integral method utilizes the principle of point source, and the operation is simple, but it is affected by the deviation of the color temperature of the standard lamp and the lamp under test, and the measurement error is large. (2) Spectroscopic method. The luminous flux is calculated from the spectral energy P() distribution. Using a monochromator, the spectrum of the standard lamp from 380 nm to 780 nm is measured in the integrating sphere, and then the spectrum of the lamp under test is measured under the same conditions, and the luminous flux of the lamp to be measured is calculated and compared. The luminous efficiency is the ratio of the luminous flux emitted by the light source to the power consumed by it, and the luminous efficacy of the LED is usually measured by a constant current method. Spectral property detection LED spectral characteristics include spectral power distribution, color coordinates, color temperature, color rendering index and so on. The spectral power distribution indicates that the light of the light source is composed of a plurality of different wavelengths of color radiation, and the radiation power of each wavelength is also different. This difference is sequentially arranged with the wavelength, which is called the spectral power distribution of the light source. The light source is obtained by comparison measurement using a spectrophotometer (monochromator) and a standard lamp. The color coordinate is a digital representation of the amount of illuminating color of the light source on the graph. The coordinate graph representing the color has a variety of coordinate systems, usually in the X, Y coordinate system. The color temperature is an amount indicating a light source color table (appearance color appearance) seen by the human eye. When the light emitted by the light source is the same as the color of the light emitted by the absolute black body at a certain temperature, the temperature is the color temperature. In the field of illumination, color temperature is an important parameter describing the optical properties of a light source. The related theory of color temperature is derived from blackbody radiation, which can be obtained from the color coordinates of the black body trajectory by the color coordinates of the light source. The color rendering index indicates the amount of light emitted by the light source that correctly reflects the color of the object, usually expressed by the general color rendering index Ra, which is the arithmetic mean of the color rendering index of the eight color samples. Color rendering index is an important parameter of light source quality, which determines the application range of light source. Improving the color rendering index of white LED is one of the important tasks of LED research and development. Light intensity distribution test The relationship between the light intensity and the spatial angle (direction) is called the pseudo-light intensity distribution. The closed curve formed by this distribution is called the light intensity distribution curve. Since there are many measuring points and each point is processed by data, it is usually measured by an automatic distribution photometer. Effect of temperature effect on the optical properties of LEDs Temperature affects the optical properties of LEDs. A large number of experiments can explain that the temperature affects the LED emission spectrum and color coordinates. Surface brightness measurement The brightness of a light source in a certain direction is the luminous intensity of the light source in the unit projection area of ​​the direction. Generally, the surface brightness meter and the aiming brightness meter are used to measure the surface brightness, and there are two parts of the aiming light path and the measuring light path. Measurement of electrical parameters of LED lamps Electrical parameters mainly include forward and reverse voltages and reverse currents. It is related to whether LED lamps can work normally. It is one of the basis for judging the basic performance of LED lamps. There are two kinds of electrical parameter measurement of LED lamps: test voltage parameters when the current is constant; test current parameters when the voltage is constant. The specific method is as follows: (1) Forward voltage. A forward current is applied to the LED lamp to be detected, and a voltage drop is generated across the two ends. Adjust the current value to determine the power supply, record the relevant reading on the DC voltmeter, which is the forward voltage of the LED luminaire. According to the common sense, when the LED is conducting in the direction of conduction, the resistance is small, and the external connection method using the ammeter is relatively accurate. (2) Reverse current. Apply a reverse voltage to the LED illuminator being tested, adjust the regulated power supply, and the current meter reading is the reverse current of the LED illuminator under test. The same as measuring the forward voltage, because the resistance of the LED is reversed when the reverse conduction is large, the current meter is connected internally. Thermal Characteristics of LED Lamps The thermal characteristics of LEDs have an important influence on the optical and electrical properties of LEDs. Thermal resistance and junction temperature are the main thermal characteristics of LED2. Thermal resistance refers to the thermal resistance between the PN junction and the surface of the housing, that is, the ratio of the temperature difference along the heat flow path to the power dissipated on the channel. The junction temperature refers to the temperature of the PN junction of the LED. Methods for measuring LED junction temperature and thermal resistance generally include: infrared micro-imager method, spectroscopy method, electrical parameter method, photothermal resistance scanning method, and the like. The surface temperature of the LED chip is measured by an infrared temperature measuring microscope or a miniature thermocouple as the junction temperature of the LED, and the accuracy is insufficient. The commonly used electrical parameter method is to use the characteristic that the forward voltage drop of the LEDPN junction is linear with the PN junction temperature, and the junction temperature of the LED is obtained by measuring the difference of the forward voltage drop at different temperatures.

Relief Tent Air Conditioner

Relief Tent Air Conditioner was developed primarily to provide air cooling in tents or transportable buildings. It not only provides greater comfort but also protects equipment and materials from hot weather damage. The Relief tent air conditioner is fitted with flexible duct and the unit itself must be located outside, Easy installing, just connect the flexible duct to Tent air conditioner and the tent,connect the power, then tent air conditioner can start to work;Quick installing, one person just one minute can finish the install.

Tent air conditioner (2)

• Easy installing, just connect the flexible duct to Tent air conditioner and the tent,connect the power, then tent air conditioner can start to work;

• Quick installing, one person just one minute can finish the install.

•The AC is built into a cabinet manufactured from galvanized and powder coated steel sheet, the steel machining by CNC machining center, with a higher structure strength;

•Top finish painting is standard Olive green, also can painting according customer`s needs;

•Can provide cooling at ambient temperature up to +60℃, tent air conditioner heat pump can provide heating at ambient temperature at -10℃;Heater Resistance can provide heating at ambient temperature at -45℃;

• Environment-friendly R410a refrigerant gas;

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• Emerson thermal expansion valve, it can exactly control the refrigerant gas volume into the the evaporator,make sure the whole system always in the best working condition when cooling and Heating;

• Connect to the mains power supply or a separate diesel generator through a 7.5 m power cable, can equip with industrial plug according needs;

• Equip two pcs insulated flexible hose for each unit, to connect the Air conditioner with the tent, tent inside is far away from the noise, give comfortable and quite tent ;

• Easy transportation, have four wheels in the bottom, can easy move on the ground.

• Temperature Control by LCD Wire Controller, Have Cooling, Heating, Dehumidification,Ventilation,Fresh Air(Customization), Purification Air(Customization) ;


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