Basic troubleshooting methods for high and low temperature test chambers:

1、 High and low temperature testing equipment. In high temperature testing, if the temperature change does not reach the test temperature value, the electrical system can be checked and the faults can be eliminated one by one. If the temperature rises slowly, you need to check the air circulation system to see if the regulating baffle of the air circulation is open normally. Otherwise, check the motor of the air circulation

Is the operation normal. If the temperature overshoot is severe, it is necessary to adjust the PID setting parameters. If the temperature rises directly and is protected against overheating, the controller will malfunction and the control instrument must be replaced.

2、 When the high and low temperature test equipment suddenly malfunctions during the test operation, the corresponding fault display prompt and audible alarm prompt will appear on the control instrument. The operator can quickly identify which type of fault it belongs to by referring to the troubleshooting chapter in the operation and use of the equipment, and then ask professional personnel to quickly troubleshoot it to ensure the normal progress of the experiment. Other environmental testing equipment may experience other phenomena during use, so it is necessary to analyze and eliminate them specifically. Regular maintenance and upkeep of environmental testing equipment, regular cleaning of the condenser in the refrigeration system, lubrication of moving parts according to the instructions, and regular maintenance and inspection of the electrical control system are essential tasks

3、 If the low temperature of the high and low temperature testing instrument cannot meet the test indicators, then you need to observe the temperature changes, whether the temperature drops very slowly or there is a trend of temperature recovery after reaching a certain value. The former needs to check whether the working chamber is dried before conducting the low temperature test, so that the working chamber can be kept dry before putting the test sample into the working chamber for further testing. If there are too many test samples placed in the working chamber, which prevent the air in the working chamber from fully circulating, after ruling out the above reasons, you need to consider whether it is a fault in the refrigeration system. In this case, you need to hire professional personnel from the Lab Companion manufacturer for maintenance. The latter phenomenon is caused by poor usage environment of the equipment. The temperature and location of the equipment placement (distance between the box and the wall) must meet the requirements (as specified in the equipment operation instructions).

At present, the company's main products include: high and low temperature test chambers, rapid temperature change test chambers, constant temperature and humidity test chambers, and high and low temperature impact test chambers.

High and low temperature laboratory applications

Can determine whether the reliability and stability performance parameters of the product are qualified. Provide a basis for predicting and improving the quality and reliability of products. Structural characteristics of high and low temperature laboratory:

The high and low temperature laboratory adopts imported advanced temperature and humidity control instruments with PID regulation, fast self-tuning, programmable control of cyclic testing, multiple parameter settings, digital display, and extremely convenient reading;

The refrigeration system adopts an original imported high cooling capacity, high-efficiency maintenance free compressor. Adopting a binary cascade refrigeration method and imported environmentally friendly refrigerant, the cooling capacity is controlled by a servo control valve imported from the United States, saving about 30% energy (compared to our previous products).

The warehouse plate unit combination structure adopts internal stainless steel and external special steel plate spray coating treatment. The internal size can be expanded arbitrarily, and it is easy to disassemble and assemble. It can be customized according to customer requirements to match the site design appearance. Cooperate with customer migration.

A high-temperature resistant sealing strip is installed between the door and the shell of the walk-in constant temperature and humidity testing machine, effectively ensuring the sealing of the working room;

It has the functions of system parameter monitoring and equipment fault protection diagnosis. When there is a fault, it is accompanied by an alarm sound to prompt the fault handling measures, and at the same time, it is recorded in the book, which facilitates maintenance personnel to understand the medical history of the equipment. Improve maintenance quality and equipment stability.

Dear customer:

Hello, our company is a high-quality development team with strong technical strength, providing high-quality products, complete solutions, and excellent technical services to our customers. The main products include walk-in constant temperature and humidity testing chambers, UV accelerated aging testing machines, rapid temperature change testing chambers, walk-in environmental testing chambers, UV aging testers, constant temperature and humidity chambers, etc. Our company adheres to the principle of building a business with integrity, maintaining quality, and striving for progress. With a more determined pace, we continuously climb new heights and contribute to the national automation industry. We welcome new and old customers to confidently choose the products they like. We will serve you wholeheartedly!

How to handle situations encountered during testing in a programmable constant temperature and humidity test chamber

The handling of interruptions in programmable constant temperature and humidity test chambers is clearly defined in GJB 150, which considers three types of interruptions: interruptions within tolerance range, interruptions under under under test conditions, and interruptions under over test conditions. Different situations have different handling methods. For interruptions within the tolerance range, when the test conditions during the interruption period do not exceed the allowable error range, the interruption time should be considered as a part of the total test time; For the interruption of under test conditions, when the test conditions are below the lower limit of allowable error, the predetermined test conditions should be reached again from the point below the test conditions, and the test should be resumed until the predetermined test cycle is completed; Rework the test sample. If the test conditions do not directly affect the interruption of the test conditions, and if the test sample fails in future tests, the test result should be considered invalid. In practical work, we adopt the method of retesting after repairing the test sample for interruptions caused by faults in the test sample; For test interruptions caused by experimental equipment reasons (such as sudden water or power outages, equipment failures, etc.), if the interruption time is not very long (within 2 hours), we usually handle it according to the under test conditions specified in GJB 150. If the time is too long, the test must be redone. The reason for applying the regulation of interrupting the test in this way is determined by the regulation of stable temperature of the test sample.

The determination of the duration at the test temperature in temperature testing is often based on the sample reaching temperature stability at that temperature. Due to differences in product structure, materials, and testing equipment capabilities, the time it takes for different products to reach temperature stability at the same temperature varies. When the surface of the test sample is heated (or cooled) and gradually transferred to the interior of the test sample. This thermal conduction process is a stable thermal conduction process, and there is a time delay when the internal temperature of the test sample reaches thermal equilibrium compared to the time when the surface of the test sample reaches thermal equilibrium. This time delay is the temperature stabilization time. For test samples that cannot measure temperature stability, the minimum required time is specified. That is, when not in operation and unable to measure, the minimum temperature stability time is 3 hours. When in operation, the minimum temperature stability time is 2 hours. In practical work, we use 2 hours as the temperature stability time. When the test sample reaches temperature stability, if the temperature around the test sample suddenly changes, there is a corresponding time delay for the test sample in thermal equilibrium, that is, in a short period of time, the temperature inside the test sample will not change too much.

During the experiment, if there is a sudden water or power outage or equipment failure, we should first seal the test chamber door, because when the test equipment suddenly stops running, as long as the door is sealed, the temperature of the test chamber door will not change sharply. In a short period of time, the temperature inside the test sample will not change too much; Then, determine whether the interruption has affected the test sample. If it has not affected the test sample and the test equipment can resume normal operation in a short period of time, we can continue the test according to the under test condition interruption handling method specified in GJB 150, unless the interruption has caused some impact on the test sample.

Dear customer:

Hello, our company is a high-quality development team with strong technical strength, providing high-quality products, complete solutions, and excellent technical services to our customers. The main products include walk-in constant temperature and humidity testing chambers, UV accelerated aging testing machines, rapid temperature change testing chambers, walk-in environmental testing chambers, UV aging testers, constant temperature and humidity chambers, etc. Our company adheres to the principle of building a business with integrity, maintaining quality, and striving for progress. With a more determined pace, we continuously climb new heights and contribute to the national automation industry. We welcome new and old customers to confidently choose the products they like. We will serve you wholeheartedly!

PCT Test Purpose and Application (1)

PCT test is generally known as pressure cooker cooking test or saturated steam test, the most important is to test the product to be tested under harsh temperature, saturated humidity (100%R.H.)[saturated water vapor] and pressure environment, test the high humidity resistance of the test product, for printed circuit board (PCB&FPC), used to carry out material moisture absorption test, high pressure cooking test... For the purpose of the test, if the product to be tested is a semiconductor, it is used to test the moisture resistance of the semiconductor package. The product to be tested is placed in a harsh temperature, humidity and pressure environment. If the semiconductor package is not good, moisture will penetrate into the package along the colloid or the interface between the colloid and the conductor frame. Popcorn effect, open circuit caused by corrosion of dynamic metallized area, short circuit caused by contamination between package pins... And other related issues.

Pressure Digester test (PCT) Structure:

The test chamber consists of a pressure vessel, including a water heater that can produce a 100% (wetting) environment. The different failures of the product to be tested after PCT test may be caused by a large amount of water vapor condensation and penetration.

Bathtub curve:

Bathtub curve (Bathtub curve, failure period), also known as bathtub curve, smile curve, mainly shows the failure rate of the product in different periods, mainly including early death period (early failure period), normal period (random failure period), wear period (degradation failure period), according to the reliability test box of environmental test. It can be divided into screening test, accelerated life test (durability test) and failure rate test. "Test design", "test execution" and "test analysis" should be considered as a whole when conducting reliability tests.

Common failure periods:

Early failure (early death, Infant Mortality Region) : imperfect production, defective materials, unsuitable environment, imperfect design. Random failure period (normal period, Useful Life Region) : external shock, misuse, changes in environmental conditions fluctuations, poor compression performance. Degradation failure period (Wearout Region) : oxidation, fatigue aging, performance degradation, corrosion.

Environmental stress and failure diagram description:

According to the statistical report of Hughes Airlines, the proportion of environmental stress caused by electronic products failure, height accounted for 2%, salt spray accounted for 4%, dust accounted for 6%, vibration accounted for 28%, and temperature and humidity accounted for up to 60%, so the impact of electronic products on temperature and humidity is particularly significant, but due to the traditional high temperature and humidity tests (such as: 40℃/90%R.H., 85℃/85%R.H., 60℃/95%R.H.) takes a long time, in order to speed up the material's hypersonic rate and shorten the test time, accelerated test equipment (HAST[High accelerated life testing machine], PCT[pressure pot]) can be used to carry out relevant tests. It is also called (degenerate failure period, wear period) test.

Laptop Test Conditions

Notebook computer from the early 12-inch screen evolution to the current LED backlit screen, its computing efficiency and 3D processing, will not be lost to the general desktop computer, and the weight is becoming less and less burden, the relative reliability test requirements for the entire notebook computer is becoming more and more stringent, from the early packaging to the current boot down, the traditional high temperature and high humidity to the current condensation test. From the temperature and humidity range of the general environment to the desert test as a common condition, these are the parts that need to be considered in the production of notebook computer related components and design, the test conditions of the relevant environmental tests collected so far are organized and shared with you.

Keyboard tapping test:

Test one:

GB:1 million times

Key pressure :0.3~0.8(N)

Button stroke :0.3~1.5(mm)

Test 2: Key pressure: 75g(±10g) Test 10 keys for 14 days, 240 times per minute, a total of about 4.83 million times, once every 1 million times

Japanese manufacturers :2 to 5 million times

Taiwan manufacturer 1: more than 8 million times

Taiwan Manufacturer 2:10 million times

Power switch and connector plug pull test:

This test model simulates the lateral forces that each connector can withstand under abnormal usage. General laptop test items: USB, 1394, PS2, RJ45, Modem, VGA... Equal application force 5kg(50 times), up and down left and right pull and plug.

Power switch and connector plug test:

4000 times (Power supply)

Screen cover opening and closing test:

Taiwanese manufacturers: open and close 20,000 times

Japanese manufacturer 1: opening and closing test 85,000 times

Japanese manufacturer 2: opening and closing 30,000 times

System standby and recovery switch test:

General note type: interval 10sec, 1000cycles

Japanese manufacturer: System standby and recovery switch test 2000 times

Common causes of laptop failure:

☆ Foreign objects fall on the notebook

☆ Falls off the table while in use

☆ Tuck the notebook in a handbag or trolley case

☆ Extremely high temperature or low temperature ☆ Normal use (overuse)

☆ Wrong use in tourist destinations

☆PCMCIA inserted incorrectly

☆ Place foreign objects on the keyboard

Shutdown drop test:

General notebook type :76 cm

GB package drop: 100cm

Us Army and Japanese notebook computers: The height of the computer is 90 cm from all sides, sides, corners, a total of 26 sides

Platform :74 cm (packing required)

Land: 90cm (packing required)

TOSHIBA&BENQ 100 cm

Boot drop test:

Japanese :10 cm boot fall

Taiwan :74 cm boot fall

Laptop main board temperature shock:

Slope 20℃/min

Number of cycles 50cycles(no operation during impact)

The U.S. military's technical standards and test conditions for laptop procurement are as follows:

Impact test: Drop the computer 26 times from all sides, sides and corners at a height of 90 cm

Earthquake resistance test :20Hz~1000Hz, 1000Hz~2000Hz frequency once an hour X, Y and Z axis continuous vibration

Temperature test :0℃~60℃ 72 hours of aging oven

Waterproof test: Spray water on the computer for 10 minutes in all directions, and the water spray rate is 1mm per minute

Dust test: Spray the concentration of 60,000 mg/ per cubic meter of dust for 2 seconds (interval of 10 minutes, 10 consecutive times, time 1 hour)

Meets MIL-STD-810 military specifications

Waterproof test:

Us Army notebook :protection class:IP54(dust & rain) Sprayed the computer with water in all directions for 10 minutes at a rate of 1mm per minute.

Dust proof test:

Us Army notebook: Spray a concentration of 60,000 mg/ m3 of dust for 2 seconds (10 minute intervals, 10 consecutive times, time 1 hour)

Introduction to the Solar Simulation Radiation Test Chamber

The solar simulation irradiation test chamber, also known as the "solar radiation protection test device", is divided into three types according to the test standards and methods: air-cooled xenon lamp (LP/SN-500), water-cooled xenon lamp (LP/SN-500), and desktop xenon lamp (TXE). The difference lies in the temperature, humidity, accuracy, time, etc. of the test. It is an indispensable testing instrument in the aging test chamber series.

The test chamber uses an artificial light source combined with a G7 OUTDOOR filter to adjust the system light source to meet the requirements of IEC61646 for solar simulators by simulating the radiation in natural sunlight. The above system light source is used to conduct the IEC61646 photoaging test on the solar cell module, and the temperature on the back of the module needs to be constantly controlled between 50 ± 10oC during the test. Can automatically monitor temperature; Configure a radiometer to control the irradiance of light, ensuring it remains stable at a specified level, while also controlling the testing time.

During the ultraviolet light cycle period in the solar simulation irradiation test chamber, photochemical reactions are usually not sensitive to temperature. But the rate of any subsequent reaction depends on the temperature. The rate of these reactions accelerates with increasing temperature. Therefore, controlling the temperature during UV exposure is crucial. In addition, it is necessary to ensure that the temperature of the accelerated aging test is consistent with the highest temperature at which the material is directly exposed to sunlight. In the solar simulation irradiation test chamber, the UV exposure temperature can be set at any temperature between 50 ℃ and 80 ℃ based on the illuminance and ambient temperature. The UV exposure temperature is adjusted by a sensitive temperature controller and blower system to achieve excellent uniformity in the temperature of this test chamber.

Dear customer:

Hello, our company is a high-quality development team with strong technical strength, providing high-quality products, complete solutions, and excellent technical services to our customers. The main products include walk-in constant temperature and humidity testing chambers, UV accelerated aging testing machines, rapid temperature change testing chambers, walk-in environmental testing chambers, UV aging testers, constant temperature and humidity chambers, etc. Our company adheres to the principle of building a business with integrity, maintaining quality, and striving for progress. With a more determined pace, we continuously climb new heights and contribute to the national automation industry. We welcome new and old customers to confidently choose the products they like. We will serve you wholeheartedly!

Structural characteristics of temperature and humidity control test chamber

Suitable for various small electrical appliances, instruments, materials, and components for wet heat testing, it is also suitable for conducting aging tests. This test chamber adopts the most reasonable structure and stable and reliable control method currently available, making it aesthetically pleasing, easy to operate, safe, and with high precision in temperature and humidity control. It is an ideal equipment for conducting constant temperature and humidity tests.

(1) The test box body is in the form of an integral structure, with the refrigeration system located at the lower rear of the box and the control system located at the upper part of the test box.

(2) Inside the air duct interlayer at one end of the studio, there are devices such as heaters, refrigeration evaporators, and fan blades distributed; On the left side of the test box, there is a Ø 50 cable hole, and the test box is a single door (stainless steel embedded door handle)

(3) The double-layer high temperature and anti-aging silicone rubber seal can effectively ensure the temperature loss of the test chamber

(4) There are observation windows, frost prevention devices, and switchable lighting fixtures on the box door. The observation window adopts multi-layer hollow tempered glass, and the inner adhesive sheet conductive film is heated and defrosted. The lighting fixtures adopt imported brand Philips lamps, which can effectively observe the experimental changes in the studio from all angles.

The refrigeration cycle of the temperature and humidity control box adopts the reverse Carnot cycle, which consists of two isothermal processes and two adiabatic processes. The process is as follows: the refrigerant is adiabatically compressed to a higher pressure by the compressor, and the work consumed increases the exhaust temperature. Then, the refrigerant exchanges heat with the surrounding medium through the condenser and transfers heat to the surrounding medium. After the refrigerant undergoes adiabatic expansion through the shut-off valve, the temperature of the refrigerant decreases. Finally, the refrigerant absorbs heat from the object at a higher temperature through the evaporator, causing the temperature of the cooled object to decrease. This cycle repeats itself to achieve the goal of cooling down.

The refrigeration system design of this test chamber applies energy regulation technology, which can ensure the normal operation of the refrigeration unit and effectively adjust the energy consumption and refrigeration capacity of the refrigeration system, so as to maintain the refrigeration system in the optimal operating state. By using Balanced Temperature Control (BTC), the control system automatically calculates the output of the heater based on the set temperature point through PID calculation when the refrigeration system is working continuously, ultimately achieving a dynamic balance.

Dear customer:

Hello, our company is a high-quality development team with strong technical strength, providing high-quality products, complete solutions, and excellent technical services to our customers. The main products include walk-in constant temperature and humidity testing chambers, UV accelerated aging testing machines, rapid temperature change testing chambers, walk-in environmental testing chambers, UV aging testers, constant temperature and humidity chambers, etc. Our company adheres to the principle of building a business with integrity, maintaining quality, and striving for progress. With a more determined pace, we continuously climb new heights and contribute to the national automation industry. We welcome new and old customers to confidently choose the products they like. We will serve you wholeheartedly!

Precision Oven Manual

Precision ovens are suitable for semiconductor devices in the electronic industry, curing and aging of electronic components, high-temperature precision testing of plastic and rubber, molding processes for telephone handle wires, as well as experimental or workshop production lines in higher education research institutions and industrial and mining enterprises that require high product temperatures.

This instrument is equipped with a two-level temperature control system, dual protection, automatic cut-off for overheating, safe and reliable. The column alarm device has a temperature rise and constant temperature light display. When using this instrument in large quantities in the production workshop, which instrument has reached the constant temperature requirement and which one is still in the heating state can be clearly seen.

The instrument liner is made of high-quality mirror stainless steel, the outer shell is sprayed with plastic, and a safety door lock is installed. The front door adopts a high-temperature resistant glass observation window, which can observe the condition of the test piece inside the box at any time.

Dear customer:

Our company has products such as rapid temperature change test chambers, UV accelerated weather resistance testing machines, and temperature and humidity control chambers. You can call our service hotline through our website to learn more about our products. Our pursuit is endless, and we welcome new and old customers to choose their favorite products with confidence. We will be dedicated to serving you!

Service conditions for high, low temperature, and low pressure test chambers

One of the usage conditions for high, low temperature, and low pressure test chambers: environmental conditions

a、 Temperature: 15 ℃~35 ℃;

b、 Relative humidity: not exceeding 85%;

c、 Atmospheric pressure: 80kPa~106kPa

d、 There is no strong vibration or corrosive gas in the surrounding area;

e、 No direct sunlight exposure or direct radiation from other cold or heat sources;

f、 There is no strong airflow around, and when the surrounding air needs to be forced to flow, the airflow should not be directly blown onto the box;

g、 The influence of magnetic field on the control circuit of the interference free test box in the surrounding area;

h、 There is no high concentration of dust or corrosive substances in the surrounding area.

Condition 2 for the use of high, low temperature, and low pressure test chambers: Power supply conditions

a、 AC voltage: 220V ± 22V or 380V ± 38V;

b、 Frequency: 50HZ ± 0.5HZ

Condition Three for the Use of High, Low Temperature, and Low Pressure Test Chambers: Water Supply Conditions

It is advisable to use tap water or circulating water that meets the following conditions:

a、 Water temperature: not higher than 30 ℃;

b、 Water pressure: 0.1MPa~0.3MPa;

c、 Water quality: meets industrial water standards.

Condition 4 for the use of high, low temperature, and low pressure test chambers: Test load conditions

The load of the test chamber should meet the following conditions every week:

a、 The total mass of the load shall not exceed 80KG per cubic meter within the working chamber volume

b、 The total volume of the load shall not exceed 5/1 of the working chamber volume

c、 On any cross-section perpendicular to the prevailing wind direction, the sum of the load areas should not exceed 3/1 of the cross-sectional area of the working chamber at that location, and the load should not obstruct the flow of airflow when placed.

Dear customer:

Our company has products such as rapid temperature change test chambers, UV accelerated weather resistance testing machines, and temperature and humidity control chambers. You can call our service hotline through our website to learn more about our products. Our pursuit is endless, and we welcome new and old customers to choose their favorite products with confidence. We will be dedicated to serving you!

The development prospects of high and low temperature wet heat test chambers are promising

Nowadays, China's environmental testing equipment industry is rapidly developing, constantly innovating and surpassing. However, compared to the international level, China has only reached the technical level of the mid-1990s. The development of modern industrial testing equipment not only depends on the level of product technology, but also involves engineering application technology. But many products in our country have already reached the level of international mainstream products, with a wide variety, complete specifications, low prices, and are very competitive in the international market; For example, the high and low temperature wet heat test chamber has reached the international product level.

The high and low temperature damp heat test chamber in China has done very well both in terms of product reliability and product precision. Now the test chamber in China is becoming more and more intelligent and integrated into the Internet. As long as you have a computer, you can control it anywhere and anytime; And the price is relatively cheaper compared to foreign countries, with the same quality but different prices. However, it is still necessary to constantly innovate technological indicators, constantly surpass oneself, and become a leader in environmental testing equipment. From the current perspective, the development path of high and low temperature wet heat test chambers is bright.

On the other hand, China's environmental testing equipment industry is accelerating from laboratories to the forefront of production, and to people's homes and lives. Portable, handheld, and personalized instruments are developing in large numbers, and commodity testing, environmental testing, and health testing have become new demand hotspots; The current trend in the development of instruments and meters is on the rise. It is believed that soon, China's leading product in the environmental testing industry, the high and low temperature wet heat test chamber, will be far ahead in terms of technology, brand, and other aspects internationally.

Dear customer:

Hello, our company is a high-quality development team with strong technical strength, providing high-quality products, complete solutions, and excellent technical services to our customers. The main products include walk-in constant temperature and humidity testing chambers, UV accelerated aging testing machines, rapid temperature change testing chambers, walk-in environmental testing chambers, UV aging testers, constant temperature and humidity chambers, etc. Our company adheres to the principle of building a business with integrity, maintaining quality, and striving for progress. With a more determined pace, we continuously climb new heights and contribute to the national automation industry. We welcome new and old customers to confidently choose the products they like. We will serve you wholeheartedly!