A temperature flow meter is a precision instrument used to measure gas flow and temperature, widely applied in environmental monitoring, air conditioning systems, industrial manufacturing, and related fields. Its fundamental principle involves detecting temperature variations caused by gas flow to accurately calculate airflow velocity and volume, thereby providing users with precise data support. The instrument's key features lie in high precision and rapid response. Typically equipped with advanced sensors, it can swiftly capture minute changes in flow rate and provide real-time feedback. Its measurement accuracy remains exceptional even under complex environmental conditions, which is particularly crucial for industrial applications requiring strict control of airflow and temperature. Additionally, the operation of temperature flow meters is relatively simple—users only need basic configuration to obtain required data. This user-friendly design makes it easy for both professionals and general users to operate. Many modern models also feature digital displays with intuitive interfaces, allowing users to quickly understand current status and enhance usability. The instrument demonstrates excellent stability, maintaining consistent measurements over extended periods without significant drift, ensuring data reliability. With continuous technological advancements, many devices now integrate data storage and transmission functions, enabling users to review and analyze historical data post-test for informed decision-making. In conclusion, the thermal anemometer has become an indispensable tool in various industries due to its high precision, rapid response, user-friendly operation, and excellent stability. In daily life and professional settings, mastering this instrument not only enhances work efficiency but also provides crucial support for scientific research and engineering applications. As a vital measurement technology in modern science, it plays a pivotal role in technological advancement.

When operating a constant temperature and humidity test chamber, it is important to be aware of potential issues during the process and ensure proper operation. Improper handling can easily lead to equipment malfunctions. However, over time, some faults will inevitably occur. In this article, we will discuss several common faults and their solutions.

1. Fault: If the temperature does not reach the set value during high-temperature testing, the first step is to check the electrical system and troubleshoot each component. If the temperature in the constant temperature and humidity test chamber rises too slowly, check the air circulation system to ensure the adjustment damper is functioning properly. If the temperature rises too quickly, adjust the PID settings. If the temperature rises too quickly and triggers the over-temperature protection, the controller may be faulty; in this case, replace the control panel or solid-state relay.
2.  Fault: If the constant temperature and humidity test chamber fails to meet the low-temperature test requirements, investigate whether the temperature drops very slowly or if it stabilizes at a certain point before rising again. If the temperature drops very slowly, check if the chamber was dried before the low-temperature test to maintain dryness. Ensure the samples are not placed too densely to prevent inadequate air circulation. After ruling out these issues, consider whether the refrigeration system is malfunctioning; in such cases, seek professional repair from the manufacturer.
3.  Fault: If the constant temperature and humidity test chamber malfunctions during operation, with the control panel displaying a fault message and an audio alarm, the operator can refer to the troubleshooting section of the equipment's user manual to identify the type of fault. Professional maintenance personnel should then perform the necessary repairs to ensure the test proceeds smoothly. Other environmental experimental equipment will have other conditions in use, which need to be dealt with according to the current situation.                                           

　The walk-in constant temperature laboratory is a crucial facility in modern scientific research and industrial experimentation. Its core principle involves maintaining a stable and reproducible experimental environment by precisely controlling temperature and environmental conditions. These laboratories typically use efficient cooling and heating systems, along with advanced temperature sensors and automatic control systems, to ensure precise temperature regulation.

   In the walk-in constant temperature laboratory, temperature changes are strictly controlled within a set range. For instance, the typical operating range is from-20℃ to +60℃, which provides excellent conditions for studying the physical and chemical properties of materials. Conducting experiments in such an environment allows researchers to avoid external temperature fluctuations, ensuring more reliable and comparable results. Additionally, the walk-in design offers experimenters greater flexibility, making it easier to test large quantities or complex equipment.

  In addition to temperature control, constant temperature laboratories can also regulate humidity, airflow, and other environmental factors to meet the needs of various experiments. For instance, in biological experiments, controlling humidity is equally important, as both excessively high and low humidity levels can affect biological samples. Therefore, these laboratories are typically equipped with humidity monitoring and control systems, using humidifiers or dehumidifiers to precisely manage the indoor air humidity, ensuring the reliability and consistency of experimental conditions.

  Furthermore, the structural design of the walk-in constant temperature laboratory takes into account both safety and ergonomics. The equipment is meticulously arranged to allow laboratory personnel to move freely within the space, facilitating smooth experimental operations. In more advanced designs, airtight doors and isolation walls are also incorporated to ensure the independence of the experimental environment, minimizing external influences.

  In summary, a walk-in constant temperature laboratory is not just a physical space; it serves as a bridge for scientific exploration. It aids researchers in investigating the performance and reaction mechanisms of materials under various complex environmental conditions, thereby driving the continuous advancement of science and technology. Whether in the development of new materials, drug testing, or climate change research, the constant temperature laboratory plays a crucial role, becoming a sacred experimental haven in the hearts of researchers.

One reason 1. Because the temperature of the constant temperature and humidity test chamber cannot be maintained, observe whether the refrigeration compressor can start when the test chamber is running, and whether the compressor can start when the environmental test equipment is running, indicating that the circuit from the main power supply to each compressor is normal and the electrical system has no problem.

2. There is no fault in the electrical system. Continue to check the refrigeration system. First, check whether the exhaust and suction pressure of the low temperature (R23) compressor of the two sets of refrigeration units are lower than the normal value, and whether the suction pressure is in the vacuum state, indicating that the refrigeration dose of the main refrigeration unit is insufficient.

3. Touch the exhaust pipe and suction pipe of the R23 compressor with your hand, and find that the temperature of the exhaust pipe is not high, and the temperature of the suction pipe is not low (no frost), which also indicates that the R23 refrigerant in the host is insufficient.

Another reason: 1. The cause of the failure has not been determined, and further confirmation is made in combination with the control process of the constant temperature and humidity test chamber. The test chamber has two sets of refrigeration units.

One is the main unit, and the other is the auxiliary unit. When the cooling rate is high, both units operate simultaneously at the beginning of the temperature maintenance phase. Once the temperature stabilizes, the auxiliary unit stops, and the main unit maintains the temperature. If the R23 refrigerant leaks from the main unit, its cooling efficiency will be significantly reduced. During the cooling process, both units operate simultaneously, ensuring stable temperatures and a gradual decrease in cooling rate. In the insulation phase, if the auxiliary unit stops, the main unit loses its cooling function, causing the air inside the test chamber to rise slowly. When the temperature reaches a certain level, the control system activates the auxiliary unit to cool down, after which the auxiliary unit stops again. The cause of the production failure has been identified as a low-temperature (R23) refrigerant leak from the main unit. Upon checking the refrigeration system for leaks, a crack was found on the valve stem of the hot gas bypass solenoid valve, measuring about 1cm in length. After replacing the solenoid valve and recharging the system with refrigerant, the system returned to normal operation. This analysis shows that the fault diagnosis follows a step-by-step approach, starting from the 'external' aspects and moving inward, then focusing on 'electricity' and finally on 'cooling.' A thorough understanding of the test chamber's principles and operational processes is essential for accurate fault diagnosis.

1. Communicate with manufacturers directly to customize requirements

 operating steps ：

Requirement submission: clear the test object (such as headlights, batteries, sensors, etc.), test scenario (such as simulated extreme cold wading, high temperature and high pressure spraying) and industry specifications (such as automobile, military, electronics);

Technology docking: provide product parameters (size, weight), environmental conditions (temperature range, impact frequency) and special requirements (such as salt spray superposition test, dynamic Angle adjustment);

Confirmation of the scheme: Based on general standards such as GB, IEC and GJB, and industry specifications such as VW 80101 and ISO 16750, the manufacturer designs customized test procedures and equipment configuration schemes.

2. Adapt to the existing standard framework

Manufacturers can expand or adjust based on the following criteria:

 national standards ：

GB/T 28046.4-2011: For the climate load test of automotive electrical equipment, the core parameters such as temperature, time and circulation times of ice water impact are defined;

GB/T 2423.1: Environmental test specification for general electrical and electronic products, supporting the design of calibration and verification process.

 codes of practice ：

VW 80101-2005: Volkswagen Electric Components Test Standard, applicable to the refinement of parameters such as spray pressure and water temperature accuracy;

GMW3172: General Motors global engineering standard, supporting multi-environment composite testing (such as ice water impact + salt spray corrosion);

ISO 16750-4:2006: International common vehicle electrical equipment test framework, compatible with customized cycles (e.g. 100 standard or 200 enhanced).

Third, optimize standards by using manufacturers' technical resources

Flexible parameter adjustment:

Temperature range: standard high temperature range 65~160℃, can be extended to-70℃ to +150℃;

Water splashing system: support flow (3~4L/3S or 80L/min), distance (325±25mm adjustable), nozzle type (gap/matrix) and other customization;

Intelligent control: the PLC system can customize the temperature switching rate (such as 20 seconds to complete the conversion from extreme cold to high temperature), data acquisition frequency and report format.

Function module superposition:

Compatible with multiple test requirements such as waterproof (IPX5-6) and dustproof (IP5X-6X);

Support dynamic Angle spraying (15 ~75 adjustable), salt spray composite test and other complex scene simulation.

4. Ensure compliance through certification and verification

Equipment calibration: the manufacturer provides half-year temperature sensor calibration service, the error is controlled within ±2℃;

Third-party verification: it is recommended to certify the temperature change rate, uniformity and other indicators of customized equipment through quality inspection institutions (such as China Electric Power Research Institute, FAW test site);

Data traceability: The test chamber supports USB export of test logs, which is convenient for quality traceability and standard iteration.

5. Service support and case reference

Technical team: Guangdong Hongzhan cooperates with universities and research institutes to provide whole-process support from demand analysis to standard implementation;

Case library invocation: You can refer to the car company case (such as 800V battery pack IPX9K test, intelligent lamp cold and hot cycle verification) to optimize and customize the standard;

After-sales guarantee: customized equipment enjoys 1 year warranty and 48 hours door-to-door maintenance to ensure the stability of standard implementation.

  The high and low-temperature impact test chamber is designed for reliability testing of industrial products under both high and low temperatures. It is used to evaluate the performance of components and materials in industries such as electronics, automotive, aerospace, shipbuilding, and weaponry, as well as in higher education and research institutions, under alternating cycles of high and low temperatures. The main features include:

1. Excellent Conductivity: The alloy cable, made by adding rare earth elements and copper, iron, silicon, and other elements from China, undergoes special processing to achieve a conductivity 62% higher than that of copper. After this process, the cross-sectional area of the alloy conductor is increased by 1.28 to 1.5 times, making the cable's current-carrying capacity and voltage drop comparable to those of copper cables, effectively replacing copper with new alloy materials.
2. Superior Mechanical Properties: Compared to copper cables, the rebound performance of the high and low-temperature impact test chamber is 40% lower, and its flexibility is 25% higher. It also has excellent bending properties, allowing for a much smaller installation radius compared to copper cables, making it easier to install and connect terminals. The special formulation and heat treatment process significantly reduce the creep of the conductor under heat and pressure, ensuring that the electrical connections of the alloy cable are as stable as those of copper cables.
3. Reliable Safety Performance: The high and low-temperature impact test chamber has been rigorously certified by UL in the United States and has been in use for 40 years in countries like the United States, Canada, and Mexico without any issues. Based on advanced American technology, the test chamber has been tested and inspected by multiple domestic institutions, ensuring its reliable safety.
4. Economic Performance Savings: When achieving the same electrical performance, the direct procurement cost of high and low-temperature impact test chambers is 20% to 30% lower than that of copper cables. Since alloy cables are only half the weight of copper cables and have excellent mechanical properties, using alloy cables can reduce transportation and installation costs by more than 20% in general buildings and over 40% in large-span buildings. Using high and low-temperature impact test chambers will have an immeasurable impact on building a resource-efficient society.
5. Excellent Anti-corrosion Performance: When exposed to air at high temperatures, alloy cables immediately form a dense oxide layer that is highly resistant to various forms of corrosion, making them suitable for harsh environments. Additionally, the optimized internal structure of the alloy conductor and the use of silane cross-linked polyethylene insulation material extend the service life of alloy cables by more than 10 years compared to copper cables.                      

When the Guangdong Hongzhan ice water impact test chamber is used in summer, the following matters should be paid special attention to to ensure the stable operation of the equipment and the accuracy of the test results:

1. Environment and heat dissipation management

  Enhance ventilation and heat dissipation High temperature in summer is easy to lead to the decrease of equipment heat dissipation efficiency. Ensure that at least 10cm space is reserved around the equipment to promote air circulation. If the equipment adopts air cooling system, the condenser surface dust should be cleaned regularly to prevent poor heat dissipation and overheating of the compressor.Control the environmental temperature and humidity. Avoid placing the equipment in the direct sunlight area. It is recommended that the laboratory temperature be kept at 25±5℃ and the humidity be lower than 85%. High temperature and high humidity environment may accelerate the accumulation of frost or condensation water on the equipment, so it is necessary to increase the dehumidification measures.

2. Refrigeration system maintenance

  Water quality and tank management Bacteria are easy to breed in summer, so use deionized water or pure water to avoid hard water scaling and blocking pipes. It is recommended to change the tank water every 3 days, and empty and clean the tank before long-term disuse.Refrigeration efficiency monitoring High temperature environment may lead to overload operation of the refrigeration system. The compressor oil condition should be checked regularly to ensure sufficient refrigerant. If the water temperature exceeds the set value (such as 0~4℃), the machine should be stopped immediately for troubleshooting.

3. Frosting and defrosting treatment

  Prevent frost aggravation When the humidity is high in summer, the frost rate inside the equipment may accelerate. It is recommended to perform a manual defrosting process after 10 cycles: set the temperature to 30℃ and keep it for 30 minutes, and then drain water to clean the ice crystals on the evaporator surface.

Optimize the test interval to avoid continuous long-term low temperature testing. It is recommended to reserve 15 minutes of buffer time between high temperature (e.g., 160℃) and ice water shock cycle to reduce the impact of thermal stress on the equipment.

4. Adjustment of operation specifications

  Parameter setting optimization According to the characteristics of the summer environment, the normal temperature recovery stage time can be shortened appropriately (the reference standard is to complete the temperature switch within 20 seconds), but it must ensure that it meets the requirements of GB/T 2423.1 or ISO16750-4 standards.Safety protection should be strengthened. Anti-freezing gloves and goggles should be worn during operation to avoid the adhesion of hands and low-temperature parts caused by sweating. Before opening the door after high temperature test, the temperature inside the box should be confirmed to be below 50℃ to prevent scalding from hot steam.

5. Emergency and long-term shutdown preparation

  Fault response If the equipment has E01 (temperature out of tolerance) or E02 (water level abnormal) alarm, you should immediately cut off the power supply and contact the technical support of the manufacturer. Do not disassemble the refrigeration pipeline by yourself.Long-term protection When not used for more than 7 days, the water tank should be emptied, power should be cut off and dust cover should be covered. At the same time, power should be on for 1 hour every half a month to keep the circuit board dry.

  Through the above measures, the impact of high temperature and humidity environment in summer on the ice water shock test chamber can be effectively reduced to ensure the reliability of test data and the service life of the equipment. The specific operation details should be adjusted according to the equipment manual and actual working conditions.

  The Guangdong Hongzhan Dust Test Chamber is primarily used to simulate natural sand and dust environments, testing the dust resistance of various products. In industries such as electronics, automotive, and aerospace, products may face challenges from sand and dust. If a product's dust resistance is inadequate, sand and dust particles can penetrate the equipment, leading to malfunctions, performance degradation, or even damage. Therefore, accurately assessing a product's dust resistance is crucial, and the Guangdong Hongzhan Dust Test Chamber provides a reliable testing platform for companies.

(1) Box structure: combination of robust and durable and sealing

The test chamber is constructed from high-quality stainless steel, which not only provides excellent corrosion resistance and protection against sand and dust erosion but also ensures good sealing to prevent sand and dust leakage, maintaining the stability of the testing environment. The interior is meticulously divided into functional areas such as the sample testing zone, sand and dust circulation duct, heating system, and control system, facilitating both operation and maintenance.

(2) Dust generation system: accurate simulation of dust environment

This is one of the core components of the test chamber. It consists of a sand and dust storage unit, a sand and dust conveying unit, and a sand and dust dispersion unit. The storage unit can hold sand and dust of various sizes and compositions as required by the test. The conveying unit delivers the sand and dust into the test chamber using either a screw conveyor or an air conveying method. The dispersion unit ensures that the conveyed sand and dust is evenly distributed in the air, creating a stable and suitable sand and dust environment for testing, ensuring that each sample is thoroughly tested under uniform conditions.

(3) Air circulation system: create stable dust airflow

The air circulation system consists of a fan, ducts, and an air filter. The fan provides the necessary power to ensure the air circulates within the test chamber. The ducts guide the airflow effectively, ensuring that the air passes through the sand and dust generation system and the sample testing area, allowing the sand and dust to fully contact the samples. The air filter effectively removes sand and dust particles from the circulating air, protecting the fan and other equipment from damage and extending their lifespan.

(4) Control system: intelligent and accurate operation core

The control system employs an advanced programmable logic controller (PLC) and a touch screen interface. Operators can easily set and monitor test parameters, such as temperature, humidity, dust concentration, and wind speed, via the touch screen. It also features automatic adjustment capabilities, allowing it to continuously monitor and precisely adjust the various parameters inside the test chamber according to preset values, ensuring that the testing environment always meets the required standards. Additionally, the control system includes fault alarm and protection functions, which can promptly issue warning signals and take protective measures in case of any abnormal conditions, ensuring the safety of both equipment and personnel.

(5) Complete workflow: efficient and rigorous testing process

  During the preparation phase, operators select appropriate sand and dust particles based on the test requirements and place them in the storage device. They then clean and inspect the test chamber and properly position the samples within the testing area. Once the test chamber is activated, the sand and dust generation system begins to operate, conveying and dispersing the sand and dust into the air. The air circulation system ensures a stable flow of sand and dust air. The control system continuously monitors and adjusts various parameters to maintain a stable test environment. During the sample testing phase, the test chamber operates according to the set schedule