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.                                           

Key Considerations for Equipment Handover to Ensure Proper On-Site Operation：

1. Equipment Installation and Commissioning

1. Dust adhering to the condenser can cause the high-pressure switch of the compressor to trip and issue false alarms. Therefore, dust attached to the cooling grid of the condenser can be removed with a vacuum cleaner every month, or by using a hard-bristled brush after turning on the machine, or by blowing it off with a high-pressure air nozzle.
2. The area around the machine and the ground at the bottom should be kept clean at all times to prevent a large amount of dust from being sucked into the unit or reducing equipment performance and causing accidents.
3. When opening or closing the door or taking samples from the test chamber, do not touch the sealing strip on the door.
4. The core of the constant temperature and humidity test chamber - the refrigeration system should be inspected once a year. Check for leaks in the copper tubes and at each joint and interface. If there are any, inform the manufacturer.
5. The humidifier and water tank should be cleaned frequently to avoid scaling and affecting steam emission. Clean them after each test. Timely descaling helps extend the lifespan of the humidification tube and ensures smooth water flow. When cleaning, use a copper brush and then rinse with water.
6. The distribution room should be cleaned and inspected more than once a year. Loose nodes can put the entire equipment in a dangerous working state, burn out components, cause fires, alarms, and endanger lives.
7. The dry and wet bulb wicks should be checked frequently. Replace them promptly if they become hard or dirty. It is recommended to replace them every three months.
8. Inspection and maintenance of the water circuit. The water pipes in the water circuit are prone to clogging and leakage. Regularly check for leaks or blockages. If found, remove them promptly or notify the manufacturer.

Selection of the installation site of the rapid temperature change test chamber:

1. The distance from the adjacent wall can smoothly give full play to the role and characteristics of the environmental test chamber. The long-term temperature of 15 ~ 45 °C and the relative environmental humidity exceeding 86% should be selected. site.
2. The working temperature of the installation site must not change significantly.
3.  It should be installed on a leveling surface (use a level to determine the level on the road during installation).
4. It should be installed in a site without sun exposure.
5.  It should be installed in a site with excellent natural ventilation.
6. It should be installed in areas where flammable materials, explosive products and high-temperature heat sources are eliminated.
7. It should be installed in a site with less dust.
8. Install it as close as possible to the switching power supply of the power supply system.

　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) Equipment Installation & Debugging

On-Site Services: Free delivery, assembly, wiring, and debugging by technicians. Parameters (temperature, humidity, salt spray settlement, etc.) must meet the client’s technical agreement.

Acceptance: Third-party calibration reports provided. Non-compliant equipment (e.g., rain test chambers requiring 100% pass rate) will be replaced immediately.

(2) Customer Training

Basic Training: Startup/shutdown, programming, and maintenance, customized for users (e.g., QA agencies, automakers).

Advanced Training: Fault diagnosis (e.g., humidity system issues in thermal chambers) and part replacement to enhance self-repair capability.

(3) Technical Support

Rapid Response: 15-minute reply to requests, 48-hour resolution for common issues (remote areas negotiated).

Remote Aid: Video guidance or software access for quick troubleshooting (e.g., abnormal dust concentration in sand/dust test chambers).

(4) Spare Parts & Maintenance

Priority Supply: Critical parts prioritized for partners (e.g., CRCC, CETC) to minimize downtime.

Transparent Costs: Free repairs for non-human damage during warranty; post-warranty services at clear rates.

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.

(1) Equipment installation and commissioning

On-site service: technical personnel will deliver the goods free of charge and complete the mechanical assembly, electrical wiring and debugging. The debugging parameters shall meet the temperature and humidity, salt spray deposition amount and other indicators in the customer's technical agreement.

Acceptance criteria: provide a third-party measurement report, and unqualified equipment shall be returned or replaced directly. For example, the rain test box shall pass 100% acceptance.

(2) Customer training system

Operation training: covers equipment start and stop, program setting and daily maintenance, customized for different user scenarios such as quality inspection institutions and automobile enterprises.

Deep maintenance training: including fault diagnosis (such as troubleshooting of humidity system in high and low temperature and humidity test chamber) and spare parts replacement to improve customers' independent maintenance ability.

(3) Technical support and response

Instant response: respond to repair demand within 15 minutes, and solve routine faults within 48 hours (negotiate with remote areas).

Remote diagnosis: through video guidance or remote access software, quickly locate the problem (such as abnormal dust concentration in the sand test chamber).

(4) Spare parts supply and maintenance

Make spare parts plan, give priority to the supply of wear and tear parts from cooperative units (such as China Railway Inspection and Certification Center, China Electronics Technology Group), and reduce downtime.

Non-manual damage is free of charge during the warranty period, and paid services are provided after the warranty period with transparent charges.