作者：Blade

China LED lights are popular in India

“Indian businessmen are constantly looking at the products and have already squeezed my booth,” Ms. Chen, who participated in the India LED Products Exhibition, lamented that although she was exhausted every day, orders from many large Indian customers were still Make her excited.

China LED lights are popular in India

The efficient lighting plan promoted by the Modi government in India has activated the huge potential of the LED market. To save lighting costs, India plans to provide 770 million LED bulbs to the public by 2018.

Since Indian LED products are mainly imported, a considerable part of them come from China. This efficient lighting plan has created huge business opportunities for Chinese LED manufacturers in India.

To understand the popularity of Chinese LED products in India, the reporter specifically visited the 2015 largest LED products and technology exhibition in India, which was held in New Delhi earlier this month.

Chinese companies account for one-third of the more than 200 exhibitors. The LED products on display include materials, chips, equipment, packaging, and lighting accessories, covering the entire LED industry chain. The reporter saw that almost every Chinese booth will be consulted by many Indian businessmen.

Ms. Chen’s Shenzhen Mingyang company mainly provides LED lighting kits for Indian lighting companies participating in government procurement, BAJAJ Electric Company and Indian IT giant Vipro. The head of Mingyang Company’s office in India told reporters that since the Modi government promoted the replacement of incandescent lamps with LED bulbs, orders began to increase steadily.

Chinese LED products enjoy the reputation of “cheap and good quality” in India. Gulabchand Haria is a businessman who does wholesale business in Mumbai and has also visited LED exhibitions in New Delhi. Haria said: “I mainly want to order LED lights from Chinese manufacturers. Although I also operate products provided by Indian suppliers, the price is more expensive than Chinese products, so the sales are not good. So I still hope to sell Chinese goods.”

The reporter saw many Indians asking about a product developed by the Chinese Academy of Sciences for driving LED lamps at the booth of Ms. Chen. Ms. Chen told reporters: “This kind of product is specially designed by experts from the Chinese Academy of Sciences according to the unstable voltage in India. Installing this kind of driver can avoid the damage to the bulb caused by the sudden voltage increase.”

Ms. Chen said that the price of this new product of the Chinese Academy of Sciences is only half of the current ordinary lamp driver on the market, but most Indian customers are still stuck in the product consulting and testing stage. After the product is approved by the market in the future, Indian customers will save half the cost. This is really “cheap and good.”

At the exhibition, the reporter saw a mandatory product registration system table issued by the Delhi test laboratory officially approved by India, which proposed many new standards for LED lighting systems related to products such as TVs, mobile phones, cash registers, and plotters. .

An industry source told reporters: “Although this can be seen as a way for the Indian government to restrict Chinese LED products, it warns Chinese manufacturers that they need to work harder to improve product quality.”

Solar street lights help Spanish city Seville improve urban safety

Recently, Xin Nuofei announced the use of solar lighting equipment to help Seville Elena Park enhance the safety of visitors. In this pilot project, Elena Park will install 20 sets of Philips Sun Stay solar street lights to jointly implement the environmental sustainability of Seville and Xin Nuofei.

Solar street lights help Spanish city Seville improve urban safety

Philips Sun Stay solar street lights integrate solar panels, lighting originals, charge controllers, and batteries in the same device, which makes it quite compact and easy to install and maintain. In addition, it will also help Seville, which adheres to environmental protection and sustainable development, reduce energy consumption, and carbon footprint.

Juan Espadasi, Mayor of Seville, said: “As a leading city in environmental protection development, Seville has always insisted on combating climate change, and its environmental protection philosophy is also in line with the 2030 Seville urban strategy and the United Nations Sustainable Development Goals. At the moment, all municipal power in Seville is 100% renewable energy. This is precisely the importance of creating green spaces in the city. This innovative commercial project can help increase the use of public space for citizens At the same time reduce emissions and achieve sustainable development. ”

Philips Sun Stay solar street lights can help reduce wiring costs and carbon footprint and reduce overall capital investment and operating expenses. Philips Sun Stay solar street light has a warm light output of 3,000lm and a luminous flux of up to 175lm per watt, which is currently the most efficient solar street light on the market.

After installing the Philips Sun Stay solar street lamp, high-quality lighting allows people to participate in more outdoor sports at night, and also makes the surrounding residents and tourists better use the city’s green public space.

“We are very happy to see the application of solar lighting in European cities.” Harsh Chitale, general manager of Xin Nuofei’s professional lighting business department, said in an interview, “I am very confident that in the future more and more European cities will The installation of solar street lighting will help fulfill our expectations of strong business development in the market segment in the coming year. ”

The new lighting system was installed in June this year. Compared with traditional lighting systems, solar street lights require less time to install. This is due to the fact that its installation project does not involve pipeline installation and other infrastructure transformation, and the input cost is less and the impact on local residents is also smaller.

This pilot project in Seville is another practice of Xin Nuofei on the concept of sustainable development. Xin Nuofei always adheres to the environmental protection commitment of “shiny life, beautiful world” and is committed to providing consumers with more efficient and energy-saving light sources and improving their quality of life. As an important part of the environmental protection commitment, Xin Nuofei has reached a carbon-neutral operation in Spain in 2017.

Annual global street lighting revenue will reach $ 1.7 billion by 2026

It is reported that in 2026, the annual global smart street lamp revenue will increase to 1.7 billion US dollars. However, only 20% of the LED street lights with integrated lighting control systems are truly “smart” street lights. According to ABI Research data, this imbalance will gradually be adjusted in 2026, and the central management system will be connected to more than two-thirds of all newly installed LED street lights.

Annual global street lighting revenue will reach $ 1.7 billion by 2026

Adar Research Chief Analyst Adarsh Krishnan said, “Smart street light vendors, including Telensa, Telematics Wireless, DimOnOff, Itron, and Signify, benefit most from cost-optimized products, market expertise, and proactive business methods. However, By hosting wireless connection infrastructure, environmental sensors, and even smart cameras to take full advantage of smart street light pole infrastructure, smart city suppliers can have more business opportunities. The challenge is to find a feasible business model to encourage large Deploy multi-sensor solutions economically at scale. ”

The most commonly used smart street light applications (in order of priority) include: remotely scheduling dimming profiles based on seasonal changes, time changes, or special social events; metering individual street light energy consumption to achieve accurate usage billing; asset management to improve Maintenance plans; sensor-based adaptive lighting, etc.

From a regional perspective, the deployment of street lighting is unique in terms of supplier and technical methods and end-market requirements. In 2018, North America has been a leader in smart street lighting, accounting for 31% of the global installation base, followed by Europe and the Asia-Pacific region; in Europe, non-cellular LPWA network technology currently occupies a major share of smart street lights, but cellular LPWA networks Technology will soon grab some market share, especially in the second quarter of 2020, there will be more NB-IoT terminal commercial equipment.

By 2026, the Asia-Pacific region will become the world’s largest smart street light installation base, accounting for more than one-third of global installations. This growth is due to the Chinese and Indian markets, which not only have ambitious LED street light retrofit plans but are also building local LED component manufacturing facilities to reduce bulb costs.

LED lights light up high-value agricultural prospects

Using science and technology to assist high cash crops is a new trend in agriculture, especially the application of LED light sources in plant growth is a major breakthrough in recent years. The Taiwan Institute of Industry Research found that replacing LED incandescent lamps with LED lights as night lighting for crops can solve the problem of yield caused by insufficient light, and can also achieve the benefits of energy conservation and power saving, and increase farmers’ income.

LED lights light up high-value agricultural prospects

At present, the intelligent LED lighting control technology of the Taiwan Industrial Research Institute has been adopted in Nantou, Hsinchu, Changhua, Taiwan’s white bamboo shoots, asparagus, strawberries and grapes, and has shown good planting results.

The LED light source can select a specific wavelength to adjust the light quantity and light quality to meet the light waves required by the plant. As a regulation of crop production period, yield, and quality, the LED optoelectronic industry in Taiwan has a complete supply chain and customized design capabilities, and advanced agricultural planting technology. In particular, it is unique in the world. If the advantages of the two are combined, it will create high-value-added LED light source applications and high-quality agricultural products with world competitiveness. With the use of LED lights, the Taiwan Industrial Research Institute lights up the road of high-value economic crops for farmers, and also makes the organic agriculture in Taiwan more transparent and bright.

The LED lamp of the Taiwan Institute of Technology was first tested in the white bamboo field in Puli, Nantou. The LED light was introduced into the white bamboo shoots in Puli, Nantou. The light was controlled by a bulb type. The bulb was directly placed above the plant so that the crop could receive uniform light, Make the efficiency of photosynthesis better.

This kind of irradiation can greatly reduce power consumption by more than half and reduce farmers’ planting costs. LED lights have the advantages of uniform brightness and no light damage, and can achieve the purpose of increasing yield, high efficiency, disease resistance, and no light damage.

Not only white bamboo shoots but local organic asparagus in Taiwan. Even in winter when there is insufficient sunlight, LED light sources to help fill up the light, maintain good quality and stable output, and become the best materials for five-star restaurant cuisine. The juicy asparagus is the result of scientific and technological cooperation between Nantou Jiujiufeng Organic Farm and the Industrial Research Institute.

The Taiwan Institute of Industry and Technology Research Institute develops a “smart greenhouse”, uses intelligent LED lighting control technology to grow organic asparagus, and introduces an IoT planting environment automatic monitoring system, which can automatically measure indoor light, air and soil temperature, humidity, electrical conductivity, and other data Through the analysis of relevant data, the light output of LED lamps is adjusted to create the best light environment for asparagus cultivation.

It has been confirmed that the total quality and efficiency can be improved by 32% through LED lighting. In the future, the software and hardware technology and production management model of this demonstration site can be completely copied and expanded to other crop production, plant factories, simple greenhouses, and other fields.

At the same time, the Taiwan Institute of Industry and Technology also cooperates with the Hsinchu Xiangshan Strawberry Garden. The use of LED light can shorten the number of days required for planting to flowering. It has been shortened by at least 10 to 15 days. Growth form, yield, quality, and inhibition of the occurrence of pests and diseases, and the added value of LED lighting technology have also made strawberry cultivation one of the high-value agriculture.

With the assistance of the Taiwan Institute of Industry and Technology, Wang Lishen, a farmer who grows grapes in Xihu Town, Changhua County, also applied LED night lighting devices to the vineyards.

Because the vineyards in Taiwan are planted in a shed, the branch of the vine shed leaves, and bear fruit on the shed. Therefore, LED lights must be illuminated from bottom to top in order to maximize the economic benefits. After constantly modifying the design and placement of LED lights Finally, successfully developed a module that can replace incandescent lamps, saving considerable electricity bills for farmers.

Advocate LED lighting industry to improve quality and efficiency

After more than 30 years of development, the Chinese LED industry has formed a relatively complete industrial chain. In 2018, the overall sales of China’s lighting appliance industry were about 600 billion RMB, of which LED lighting sales were about 260 billion RMB. China has become the world’s largest producer and exporter of lighting appliances, with a global market share of more than 50%. As semiconductor manufacturing companies and electronics manufacturing companies enter the LED lighting market, competition is fierce. At the same time that major manufacturers are expanding, they are also turning to focus on independent research and development to improve product quality and increase product competitiveness or the general trend.

Advocate LED lighting industry to improve quality and efficiency

Last year, Debang Lighting stabilized and maintained its leading position in the LED light source product industry, achieving an operating income of 4.244 billion RMB, an increase of 6.21% year-on-year, of which domestic revenue contributed a greater increase. Domestic revenue was 1.362 billion RMB, an increase of 42.25% year-on-year. Product structure, sales of LED intelligent lighting products and control systems, increased product value-added gross margin reached 18.77%, an increase of 3.14 percentage points from 15.63% in the previous year. In addition, the domestic LED general lighting leader Optronics had a revenue of 5.77 billion RMB in the first three quarters of last year, an increase of 3.26% year-on-year. Since the transformation for nearly 8 years, it has maintained a growth rate of more than 10%. OP Lighting’s gross profit margin reached 36.41%, which remained basically the same as last year and maintained its leading position.

And Sunlight has an annual production capacity of 400 million LED light sources and 100 million sets of LED lamps. LED products account for about 94% of the revenue. The performance report of Sunshine Lighting shows that last year it realized operating income of 5.321 billion RMB, a decrease of 5.26% over the same period of the previous year, and realized a net profit of 467 million RMB attributable to shareholders of listed companies, an increase of 21.39% over the same period of the previous year. The company increased its investment in independent brands and products, and the proportion of independent brand revenue continued to increase. The gross profit margin of Sunshine Lighting in the first three quarters was 31.37%, which was 7.09 percentage points higher than the previous year’s 24.28%. There are currently 32 listed LED lighting companies. Infineon ’s gross profit margin was 37.56% in the first three quarters, an increase of 4.03 percentage points from 33.53% in the previous year, and Jufei Optoelectronics ’gross profit margin was 27.68%, an increase of 5.82 percentage points. However, it specializes in LED chips. The gross margin of Sanan Optoelectronics has declined, mainly because the price of LED chips has dropped significantly compared to the same period last year.

After the development of the LED lighting market in recent years, it has shifted from the expansion of scale to increase the added value of products and increase gross profit margin. The global LED lighting market has formed three major lighting markets, mainly in North America, Europe, and China. The domestic lighting consumer market has accounted for a slight decline in the growth rate of more than 20% of the global lighting market. In 2019, the global lighting industry’s mergers and acquisitions accelerated, and the concentration of more than 50 large-scale mergers and acquisitions in the industry has increased throughout the year. Therefore, in the fierce competition, Yaboww sought Com to improve product quality and increase its own advantages, thereby maintaining a large Competitiveness. Compared with the high concentration of mature markets such as the United States, Japan, and South Korea, China’s LED general lighting industry is more fragmented. Driven by factors such as increasing technical requirements for the integration of light sources and market demand from single product purchases to overall lighting solution design, the industry ’s concentration will increase in the future and the Hengqiang effect is expected to appear.

How is the facade lighting of Guangzhou East Tower created?

Guangzhou East Tower Curtain Wall Lighting Project, located in the East Tower of Chow Tai Fook Financial Center in Zhujiang New Town, Guangzhou City. The tower is 111 stories above the ground, with a total height of 530 meters and a curtain wall area of approximately 120,000 square meters.

How is the facade lighting of Guangzhou East Tower created?

The fa?ade lighting of the tower is divided into two parts: low-level and top-level traditional lamps and mid-to-high-level LED lamps. Traditional luminaires include the first two and six layers of canopy downlights and floodlights, three to nine layers of spotlights, and top spotlights; mid-to-high-level LED luminaires to include forty-level to top-level scattered starlight installation, seventy to the top strip lights are arranged.

LED luminaires of this project are concealed in the curtain wall structure, the luminaires cannot be seen on the floor, and the appearance color is similar to the curtain wall structure, which does not affect the appearance of the building during the day.

In terms of power supply for lamps, the power supply of LED lamps is centralized in the control room on the equipment level, eliminating the need to occupy other functional rooms, and it is convenient and quick to debug and maintain. In terms of the lamp control system, LED strip lights to use 40 pixels/meter high-resolution lamps to make the lights easy to control to achieve the effect of soft gradient.

The control system has the function of lamp status feedback, the administrator can clearly understand the operation status of the lamp in the main control room, find the problem in time, and fix the problem at a fixed point.

The LED lamps (star lights and linear floodlights) in this project are installed in the curtain wall factory, and the lamps follow the curtain wall.

The hand-to-hand connection of the lamps inside the unit is completed in the curtain wall factory. After the unit lamps and the mainline are connected to the upper wall of the unit, the hanging wall equipment is used to connect the external walls.

Sanan Optoelectronics plans to invest in Mini / Micro LED epitaxy and chip projects

On April 25th, Sanan Optoelectronics issued an announcement and announced that it had signed a project investment contract with the Management Committee of Hubei Gedian Economic and Technological Development Zone, with a total investment of 12 billion yuan.

Sanan Optoelectronics plans to invest in Mini / Micro LED epitaxy and chip projects

In order to promote the company’s III-V compound semiconductor project R & D and industrial base to settle in the Gedian Economic and Technological Development Zone in Hubei Province as soon as possible, Sanan Optoelectronics and the Hubei Gedian Economic and Technological Development Zone Management Committee adhere to the principles of complementarity and mutual benefit. After a friendly negotiation, a cooperation contract was reached.

The contract stipulates that San’an Optoelectronics will invest in an III-V compound semiconductor project within the jurisdiction of the Management Committee of Gedian Economic and Technological Development Zone in Hubei Province. It will mainly produce R & D, production and sales of Mini / Micro LED epitaxial and chip products and related applications. And invested by Sanan Optoelectronics in this jurisdiction, the total investment is 12 billion yuan.

Sanan Optoelectronics is a leading III-V compound semiconductor and integrated circuit company. It is a substrate integrated circuit, epitaxial, chip R & D and industrialization base. enterprise. It has a national post-doctoral research workstation and a national enterprise technology center and has undertaken a number of key research projects such as the “863” and “973” plans. Has been identified by the National Development and Reform Commission, the Ministry of Science and Technology, the Ministry of Industry and Information Technology as “National High-tech Industrialization Demonstration Project Unit”, “Semiconductor Lighting Engineering Leading Enterprise.” The national integrated circuit industry investment base is the second-largest shareholder of Sanan Optoelectronics.

Sanan Optoelectronics stated that Mini / Micro LED is one of the company’s key development directions in the future. This investment project is in line with the national industrial policy plan and the company’s industrial development direction and development strategy, which is conducive to improving the company’s product structure, enhancing the company’s core competitiveness, and consolidating the company’s industry position. All directors agreed to invest in this project.

LED lamp power deviation analysis

The high incidence of “quality gate” incidents in LED lighting products is, on the one hand, the lack of industry standards and supervision, and on the other hand, the company’s own quality awareness, weak design capabilities, and technical level defects.

LED lamp power deviation analysis

This article takes the LED lamp power deviation out of control as an example. The theoretical calculation combined with case calculations analyzes in detail the constant current accuracy of the driving power supply. The forward voltage drop of the LED affects the deviation of the lamp power for designers’ reference to improve the design quality of LED products.

Recently, various media have frequently reported national and local quality inspection departments to spot check LED light sources and LED lamps for substandard quality incidents. The high-quality “quality gate” incident has seriously damaged the company’s own image and the brand image of China’s LED industry on the international stage.

In the non-conformity test project, the actual test power of the lamp does not match the declared power of the product. As early as 2010, China has released the national standard GB / T24908-2010 “Performance requirements for self-ballasted LED lamps for general lighting” in Article 5.3, “When the lamp works at rated voltage and rated frequency, its actual power consumption and rated The difference in power should not be greater than 15% or 0.5W “, and the International Electrotechnical Commission also required in paragraph 7 of IEC62722-2 that” the deviation between the nominal value and the actual value of the electrical parameters of the lamp should not be greater than 10%. ”

The author believes that the reasons for product power deviation are as follows:

First, due to cost pressures, the production process cut corners and cut materials, eliminating the necessary product testing process, the unqualified products have not been removed in the factory and flowed to the market in good time.

Second, the LED lamp beads have insufficient cooling design margins. The assembly process and the deviation of the incoming materials cause the lamp beads to overheat, and the forward voltage drop (Vf) drops out of control, causing the actual power of the lamp to deviate from the lower limit.

Third, the optional drive power supply of the lamp has poor thermal stability and large output current temperature drift, which directly causes the lamp power to deviate in a wide range.

Fourth, in order to reduce the purchase cost of LED lamp beads, the LED Vf distribution BIN was not selected according to the design requirements, causing the actual power consumption of the LED to deviate from the design center value.

Fifth, the constant current accuracy of the optional drive power supply is low (usually 5% -8%), and it cannot adapt to the various Vf BINs of the lamp beads.

The author believes that the first three reasons directly reflect the manufacturer’s weak quality awareness and have little relevance to the design. This article does not review them. The last two reasons have a strong correlation with the precision design of the driving power of the lamp. The specific analysis is as follows:

Assume that the drive power accuracy (△ I) is 5%. To meet the IEC power nominal requirements, P is within 10%. According to the expression [1], the LED lamp string voltage deviation percentage (△ U) is about 4.8. %, Which means that the LED lamp beads Vf BIN must be screened strictly, which directly causes the invisible lamp bead procurement costs to rise.

For example, the engineer selects 12 lamp strings with a design center value of 36V for OSRAM LCW CRDD series lamp beads (Vf BIN table is as follows).

If a constant current accuracy 5% driving power source is selected, the minimum value of the voltage drop of the string is 34.27V and the maximum value is 37.72V.

It is not difficult to find the Vf BIN distribution table of lamp beads. Without effective measures to mix BINs, nearly half of the lamp beads cannot be used in mass production, and the purchase cost of lamp beads has increased significantly indirectly.

If a constant-current precision 1% drive power source is used, the minimum value of the string voltage drop is 32.79V and the maximum value is 39.204V, which completely covers the lamp bead Vf BIN, without any measures to mix BINs. Production costs and procurement costs are greatly reduced.

It is not difficult to see through the comparative analysis of the above cases that the high-precision drive power can effectively avoid the trouble of the lamp factory’s complicated and unpredictable proportion of lamp beads mixed-use, greatly reducing the overall system cost, and the “small cost” of the power source in exchange for the “big benefit” “.

LED lighting competition has become fierce, and product prices have continued to decline. Low-cost strategies at the expense of product quality or even violation of industry norms and regulations are not desirable. Technical personnel in the LED industry must explore low-cost solutions on the premise of meeting product quality requirements so that ordinary people can afford high-quality LED lighting products.

Is PoE lighting finally here?

PoE was originally used in a proprietary Voice over IP (VoIP) system developed by Cisco in 2000. Each new generation of PoE standards and technologies includes higher power specifications. At the same time, the efficacy of LED lamps is also increasing year by year. By 2017, the 25.5W limit stipulated by the IEEE 802.3at standard, which has now been replaced, is enough to power nearly a quarter of the lamps in the room.

Is PoE lighting finally here?

The IEEE Standards Council approved the IEEE 802.3bt standard on September 27, 2018, including some important improvements to LED lighting systems. The main driver of this improvement is the use of four pairs of network cables to transmit up to 90W of power over 100m of cable. This allows multiple fixtures to be daisy-chained, simplifying the installation process.

Other enhancements in the new specification include increasing the efficiency of current PoE levels (that is, 25.5W output power), as the power consumption of the cable is reduced by approximately half. For example, a power supply device operating under the previous standard needs to provide at least 30W of power to ensure that the powered device receives 25.5W of power, as Ethernet cables may lose up to 4.5W of power. Powering the same device under the new standard will reduce losses to below 2.25W and increase efficiency by about 7%.

In addition, power supply equipment can now determine the maximum power consumed by each connected device and set the output power accordingly, thereby improving the operating efficiency of the entire system. Finally, as the duty cycle required to maintain the power signature is reduced, the standby power requirement is now reduced, and the only 0.02W is required to maintain the power connection. Since energy efficiency is likely to be the most compelling selling point of LED lighting systems, changes to the new specification will help advance the development of PoE control systems.

The author recently visited Carthage, Missouri for a visit to H. E. Williams. The details of the PoE system are very instructive. As shown in Figure 1, a PoE lighting system includes five basic components: a network controller, a user interface, a PoE switch, lamps, and auxiliary equipment such as sensors or switches.

The data and power receiving of the luminaire is achieved by adding a “node” in the luminaire housing and connecting it to the power and dimming input of the LED light engine. Depending on the function of the connected luminaire and its associated auxiliary equipment, this node can also handle other functions. Igor’s nodes allow multiple devices to connect to a PoE network.

According to the new IEEE 802.3bt standard, Igor has made some modifications to its node shape to make it closer to the size of traditional LED drivers. Another great enhancement is the addition of a USB port, as shown in the bottom left corner of Figure 3.

As the number of AC-DC power conversions is reduced, PoE lighting systems can provide higher overall energy efficiency compared to traditional AC power systems. Ethernet cable loss appears to be a major consideration in assessing total system power consumption, and this indicator is especially important for end users who want to gain subsidies by improving energy efficiency.

“NEMA / ANSI C137.3-2017 Minimum Requirements for Installation of Energy Efficient Power over Ethernet (PoE) Lighting Systems” document provided Installation requirements. Specifically, the standard specifies a minimum wire gauge, which requires the average resistance wire loss to be less than 5% of the total transmission power (assuming an average cable length of 50 meters). However, because each installation is more or less different, the total loss must be evaluated on a case-by-case basis. There are no guiding standards for assessment methods.

Performance requirements for glass tubes for LED lamps

The performance of the straight tube type LED lamp housing glass tube mainly includes the appearance effect, light transmittance, fogging degree, temperature and humidity resistance, moisture resistance, hardness, conductivity, expansion rate, bending degree, and the color parameters of the entire light.

Performance requirements for glass tubes for LED lamps

Key indicators are as follows:

①Appearance effect: Generally the color is milky white, the surface is smooth, no bubbles, no scratches, no spots, etc .;

②Transmittance: Test calculation method, using the same light source at the specified voltage and power respectively apply transparent glass tubes and milky white glass tubes of the same specifications, using an integrating sphere to its photoelectric color parameter test, milky white and transparent light effect. The ratio is the light transmittance. Generally, the light transmittance is required to be above 92%;

③Atomization degree: Put the matched light source (lamp beads) device in the glass tube, light the lamp at the rated voltage and power, and you can’t see the light-emitting point (lamp beads). Consistent performance, no obvious difference between light and dark;

④Temperature resistance: Put the glass tube in a high-temperature box of 150 ℃. After 200 hours, there is no color change, no burst, no deformation, etc .;

⑤Water resistance: Put the glass in a constant temperature water bath at 60 ℃. After 24 hours, there will be no color change, no cracks, no distortion, etc .;

⑥ Expansion coefficient fluctuation: The expansion coefficient fluctuation of the same batch of glass tubes shall be controlled within ± 1 × 10-7 / ℃;

⑦Conductivity: The inner and outer walls of the glass tube are required to be non-conductive;

⑧Light color effect: milk-white glass tube and transparent glass tube use the same light source to test light color parameters, and the spectrum, color temperature, and color rendering index must not be significantly different;

⑨Hardness: Take T8 glass as an example, the general pressure required to test the vertical pressure using a general glass pressure gauge is greater than 300N, which depends on the customers of each manufacturer

⑩ Bend: Take T8-1.2 meters long glass tube as an example, the bend is generally not required to exceed 3 °.

Among the above properties, most manufacturers pay more attention to the influence of light transmittance, fogging degree, temperature and humidity resistance, and light color.