The SF6 micro moisture tester (also known as SF6 dew point meter or SF6 humidity tester) is a crucial piece of equipment in industries such as power, petrochemical, and manufacturing. The selection process for SF6 micro moisture testers can follow a clear path of identifying core requirements, determining principles, comparing functions, and evaluating the accompanying features. Specifically, it can be considered from the following core aspects:
1. Determine core requirements and budget
In the early stage of selection, key questions need to be clarified to quickly narrow down the range of instrument options:
The core application scenarios of the instrument, whether for laboratory precision research or on-site rapid detection;
The testing frequency of the instrument, which needs to match the requirements of high-frequency or low-frequency testing;
Whether there are mandatory requirements for environmental protection and gas recovery;
Clarify the budget range for instrument procurement.
Different requirements correspond to different types of instruments. For example, in laboratory scenarios that pursue ultimate precision, and for maintenance teams that need to frequently move to different locations and are lightweight and efficient, the types of instruments applicable are significantly different.
2. Select measurement principle
The current mainstream measurement principles of SF6 micro moisture testers are divided into three types. The performance characteristics and applicable scenarios of different principles are significantly different:
Capacitive resistance method (polymer film capacitive type)
This method is the current mainstream and recommended solution, especially suitable for on-site use scenarios. Its core advantages are fast response, high measurement accuracy, strong anti-pollution ability, and good operational stability, which can well balance equipment performance and portability.
Electrolysis method (pentoxide phosphorus P₂O₅)
This method belongs to a classic measurement method and has direct advantages for measuring high-concentration moisture, but it also has disadvantages such as slow response, high gas consumption, and the need for regular maintenance of the sensor, and is inconvenient for measuring extremely dry gases. Currently, this method has gradually been replaced by the capacitive method, and is commonly seen in older instruments or specific laboratory-specific instruments.
Cold mirror method
This method is the internationally recognized benchmark measurement method, with a high measurement accuracy, often used for laboratory calibration or scientific research scenarios. However, such equipment has a high procurement cost, complex operation procedures, and is sensitive to environmental vibration, and is not suitable for on-site operation work.
Selection conclusion: For the vast majority of on-site application scenarios in the power industry, the SF6 micro moisture tester based on the capacitive resistance method should be prioritized.
3. Review key performance and functions
After determining the measurement principle, further compare the detailed functions of the instrument, and focus on the following core dimensions:
Measurement range and accuracy
The instrument’s measurement range needs to meet a wide range requirement, at least covering the -60℃ ~ +20℃ dew point range; the measurement accuracy usually requires better than ±2℃ dew point, to ensure that it can meet the precise measurement of new gas (typically requiring dew point < -50℃) and operating equipment (allowable value for dew point is approximately – 25℃) over the entire range.
Automation and intelligence level
One-click automatic measurement function is a key configuration for on-site use. The instrument should have the ability to automatically control the gas path, automatically determine the measurement end point, and automatically convert the value at 20℃ standard temperature. Through automated operation, human error can be reduced and test efficiency can be improved.
Data management capability
The instrument should be equipped with a large-capacity data storage module, support historical data query, and be able to directly export test reports via USB or Bluetooth. A complete data management function is the basis for achieving equipment status trend analysis and compiling standardized test reports.
Gas path design and environmental friendliness
Built-in filter: As a necessary configuration of the instrument, it is used to filter the decomposition products and solid particles in SF6 gas, protecting the precision sensor from contamination and extending the equipment’s service life.
Gas recovery function: This function is an important indicator to distinguish the quality of the instrument. Ordinary type instruments directly discharge the gas after measurement; High-end environmentally friendly instruments have a closed-loop self-recycling function. After testing, the gas can be dried and compressed back into the equipment or a dedicated gas cylinder, achieving zero gas emissions. This function not only meets environmental protection requirements but also saves the cost of SF6 gas usage.
Portability and Durability
The key points to focus on include the overall weight of the machine, battery endurance, and the strength of the casing. It is recommended that the battery endurance time be no less than 8 hours. The indicators of portability and durability directly affect the operational experience and execution efficiency during on-site work.
IV. Compliance Verification and After-sales Service
Standard Compliance
The instrument must comply with relevant industry standards and national metrological regulations, such as the Chinese “DL/T 506-2018″ power industry standards, and the factory inspection must be carried out in accordance with national metrological regulations to ensure that the measurement data of the instrument is authoritative and compliant.
After-sales Service Capability
It is recommended to choose a brand with a complete after-sales service system. Key inquiries should be made about the calibration cycle, calibration cost, and specific procedures of the sensor. As the core component of the instrument, the sensor needs to be professionally calibrated regularly to ensure the long-term stable operation of the instrument.
Selection Summary Suggestions
For regular power operation teams, a portable instrument based on the capacitance-resistance method, with automatic measurement, data storage, built-in filtering function, and reliable accuracy, is a cost-effective and practical choice. If the budget is sufficient and the testing work is frequent, it is recommended to prioritize the model with the self-recycling function. This type of instrument represents a more advanced and environmentally friendly technical direction, and at the same time, it has lower total life cycle usage costs.
After determining two to three candidate instrument models, you can experience the performance of the instrument through on-site operation demonstrations to make the optimal selection decision.
Post time: Jan-16-2026