Ring-11 Tuning Fork Level Switch for Vacuum Electrical Equipment
In ultra-high-voltage power transmission and distribution, renewable energy, aerospace, and advanced equipment manufacturing, processes such as vacuum drying and vacuum impregnation directly affect the drying efficiency, impregnation quality, and long-term reliability of insulation components.
Vacuum processing systems typically include multiple functional units for liquid storage, circulation, condensation, recovery, and separation. During operation, the equipment passes through several stages, including vacuum generation, vacuum breaking, liquid filling, drainage, and medium circulation.
Some level detection points are located in extremely confined spaces. The process medium may also be complex and subject to liquid flow, mechanical vibration, and frequent operating-condition changes. These conditions place demanding requirements on the structural dimensions, switching repeatability, and interference resistance of level switches.
Recently, the technical and sales teams of Shenzhen Jiwei visited one of China’s leading vacuum electrical equipment manufacturers. The team inspected the installation and operation of Ring-11 tuning fork level switches in the customer’s vacuum processing systems and held detailed discussions with the customer’s technical, production, and equipment personnel.
1. Leading Equipment Manufacturer Advances Component Localization
The customer visited during this project was established in 1997. It is a state-owned high-tech enterprise specializing in the research, development, manufacturing, sales, and servicing of vacuum technology equipment.
After nearly 30 years of development, the company has become one of China’s leading manufacturers in the vacuum electrical equipment industry, with a domestic market share exceeding 30%.
Its main businesses include complete vacuum systems, new-material processing equipment, optoelectronic equipment, and environmental protection equipment. Its products are widely used in ultra-high-voltage power transmission and distribution, aerospace, renewable energy, superconductivity, rail transportation, and marine engineering. The company also exports equipment to more than 40 countries and regions.
As its production scale and overseas business continue to expand, the customer’s expectations for supporting instrumentation have moved beyond basic detection functions. Greater emphasis is now placed on:
- Product stability
- Installation compatibility
- Standardization
- Delivery lead time
- Technical and after-sales support
Although a level switch is only a basic component within a complete vacuum system, its signal may directly control pump start and stop functions, valve operation, liquid presence detection, and system interlocking.
Signal fluctuations, false switching, or failure to operate can affect equipment commissioning efficiency and process continuity.
To support the localization of core components and optimize its supply chain, the customer began testing domestic level detection products based on different measurement principles. The Ring-11 tuning fork level switch was subsequently introduced into the customer’s equipment validation and supply system.
2. Reliable Detection of Water-Oil Mixtures
The process medium in this application is not pure water or oil. It is a mixture of both.
During equipment operation, the water-to-oil ratio, density, flow condition, and degree of separation may vary according to the process stage. Some operating conditions may also generate bubbles, surface turbulence, and short-term liquid impact, creating additional challenges for level detection equipment.
Measurement technologies that depend heavily on conductivity or dielectric constant may be affected when the proportion of water and oil changes. In some applications, parameters may need to be readjusted according to the actual medium conditions.
The Ring-11 tuning fork level switch detects point level by monitoring changes in the vibration frequency of its fork.
After precise tuning, the Ring-11 can detect liquids with densities as low as 0.5 g/cm³. Its broad density range provides a reliable basis for detecting water-oil mixtures whose composition and density may change during operation.
When the tuning fork is exposed to air, it vibrates at a predefined frequency. Once the water-oil mixture covers the fork, the vibration frequency and amplitude change. The electronic module evaluates this feedback and determines whether liquid is present, then provides the corresponding switching output.
This measurement principle does not depend on the color, transparency, or electrical conductivity of the process medium.
Even when the water-to-oil ratio changes within a certain range, the switch can continue determining whether the fork is covered by liquid. This helps reduce the influence of changing electrical properties on the detection result.
According to the customer’s on-site technical personnel:
“The medium here is a mixture of water and oil, and its condition changes during operation. The tuning fork mainly determines whether liquid is present at this position. We do not need to readjust it repeatedly just because there is slightly more oil or water, which makes it convenient to use.”
3. A 40 mm Short Fork for Confined Installation Spaces
Another important feature of this project is that the level switches are installed in locations resembling pipelines rather than conventional large storage tanks.
The internal installation space is limited, while the medium remains in a flowing or circulating state.
The level switch must allow the fork to make sufficient contact with the liquid. At the same time, the probe must not be so long that it interferes with the pipe wall, internal structures, or nearby components.
The Ring-11 has a fork length of only 40 mm and features an ultra-compact sensing structure.
Its short fork makes it suitable not only for vessels, tanks, and storage containers, but also for conduits, pipelines, and other space-restricted locations.
The design provides several practical advantages:
- Reduced installation spaceThe compact fork lowers the risk of interference with pipe walls or internal equipment structures.
- Lower exposure to direct liquid impactBecause the fork extends only a short distance into the medium, the mechanical force generated by direct flow impact is relatively limited.
- Reduced residual liquid adhesionThe smaller surface area helps water-oil mixtures leave the sensing fork quickly after drainage, reducing the possibility that residual liquid will delay switch reset.
- Greater installation flexibilityCustomers can more easily adjust the mounting angle and fork orientation according to the equipment structure.
During installation, the customer adjusted the direction of the tuning fork according to the pipe arrangement and liquid flow direction.
This allowed the liquid to enter and leave the fork gap smoothly while minimizing continuous direct impact on the front of the sensing fork.
A member of the customer’s assembly team explained:
“The installation position is very compact and is similar to mounting the switch on a pipeline. If the tuning fork is too long, both the available space and the liquid-flow impact must be considered. The Ring-11 has a short fork, which makes the installation layout easier.”
4. Multiple Detection Points Participate in Equipment Interlocking
A large vacuum processing system from this customer normally uses several Ring-11 tuning fork level switches.
The switches are installed at different process points to determine whether liquid is present at critical locations.
Their signals participate in the control and interlocking of pumps, valves, and the main control system. Although each switch monitors only one point, the combined signals form an important part of the liquid-circulation and safety-protection logic.
For this reason, the customer is concerned not only with whether an individual level switch operates correctly, but also with the long-term consistency of multiple installed units.
If one detection point produces intermittent signal fluctuations, it may cause abnormal control-program decisions and increase the difficulty of commissioning and troubleshooting.
According to the customer’s commissioning personnel:
“One machine currently uses four tuning fork switches, and all of their signals participate in the control logic. During commissioning, we are particularly concerned about repeated signal fluctuations at any individual point because they are difficult to troubleshoot. The Ring-11 switches currently operate decisively, and the status of the different detection points is consistent.”
5. Connection Adaptation from Threaded to Clamp Mounting
Based on the initial product selection, Jiwei supplied Ring-11 tuning fork level switches with threaded process connections.
During the equipment design and assembly process, the customer developed a connection adapter according to its pipeline structure, assembly method, and future maintenance requirements.
The adapter allowed the threaded Ring-11 level switch to be installed through a sanitary-style clamp connection.
During the follow-up visit, Jiwei’s technical and sales personnel entered the customer’s factory to inspect the actual installation structure.
The team reviewed:
- Mounting direction
- Fork position
- Connection adapter design
- Wiring clearance
- Equipment operating condition
The customer’s assembly personnel commented:
“Jiwei supplied the threaded model. We designed an adapter according to our equipment interface and converted it to clamp mounting. This allows us to continue using a tuning fork product that has already been validated while making assembly and future removal more convenient.”
6. Comparison of Multiple Technologies Highlights Tuning Fork Stability
As a leading manufacturer in China’s vacuum electrical equipment industry, the customer has extensive experience supplying customized equipment for different industries and technical standards.
Its technical and equipment teams are familiar with numerous instrument brands, operating principles, and field-performance characteristics.
In previous projects, the customer had used several types of level detection products, including:
- Float level switches
- Magnetostrictive level transmitters
- Microwave level switches
The customer’s technical manager stated:
“We have used many instrument brands and technologies on our equipment, including float switches, magnetostrictive level transmitters, and microwave level switches. We also configure instruments according to the end user’s requirements. For this water-oil mixture and installation position, the tuning fork level switch currently provides better stability.”
Different level measurement principles have their own appropriate application ranges.
The customer’s positive assessment of the Ring-11 is based on the actual medium, available installation space, and control requirements of this particular project. It should not be interpreted as a general rejection of other measurement technologies.
7. Resistance to Liquid Disturbance and Mechanical Vibration
During operation, vacuum pumps, circulation pumps, and other powered equipment generate a certain level of mechanical vibration.
Liquid circulation inside the pipeline may also create flow impact, bubbles, and temporary fluctuations.
For a tuning fork level switch, accurately distinguishing between frequency changes caused by liquid contact and those caused by external mechanical disturbance is essential for stable switching performance.
The Ring-11 uses a precisely tuned fork structure and vibration-detection technology to determine whether the process medium has reached the sensing position.
Its stable frequency detection and signal-processing system help reduce false switching caused by:
- External vibration
- Surface movement
- Air bubbles
- Changes in medium properties
- Temporary liquid impact
The compact 40 mm fork also offers good mechanical rigidity, helping reduce the effect of pipeline flow impact and equipment vibration on the fork’s operating state.
Field operation showed that all four Ring-11 switches maintained stable switching outputs during equipment startup, shutdown, medium circulation, and pump operation.
No significant repeated signal fluctuations were observed.
The customer’s equipment manager said:
“There is both medium flow and equipment vibration at this position. We are concerned not only with whether the switch operates when the liquid arrives, but also with whether it generates false alarms while the equipment is running. The Ring-11 signal is currently stable and has not created additional problems during commissioning or operation.”
8. Moving Toward a Standardized Equipment Solution
Based on previous operating results and the latest on-site follow-up visit, the customer has developed a clearer understanding of the Ring-11 tuning fork level switch and its suitability for related vacuum equipment.
The customer exports its products to more than 40 countries and regions.
The multiple output options and relevant certifications available for the Ring-11 also provide greater flexibility when equipment must comply with different end-market requirements.
The customer’s equipment manager stated:
“Whether a domestic instrument can become a long-term supporting product depends on its actual performance on the equipment. The Ring-11 is currently operating stably, and its dimensions suit our installation position. We will continue considering it for future equipment operating under similar conditions.”
9. Conclusion
Selecting a level instrument for vacuum processing equipment involves more than comparing measuring range, accuracy, or purchase price.
The selection process must also consider:
- Process-medium properties
- Available installation space
- Liquid-flow conditions
- External vibration
- Required control functions
- Long-term signal stability
The Ring-11 tuning fork level switch combines a 40 mm ultra-short fork, liquid detection down to 0.5 g/cm³, no mechanical moving parts, strong resistance to vibration and medium-property changes, and multiple electrical output options.
These characteristics have enabled the Ring-11 to deliver stable and adaptable point-level detection in the customer’s vacuum processing equipment.
The customer’s preference for the tuning fork level switch was not based solely on product specifications. It resulted from the instrument’s long-term performance with the actual medium, actual installation structure, and actual equipment-interlocking logic.
This factory visit also demonstrated that the value of industrial instrumentation extends beyond the product itself.
A reliable instrument supplier must understand the customer’s equipment structure, process-medium characteristics, and control logic, and then provide accurate product-selection and installation support based on real operating conditions.