Fork-11 Tuning Fork Level Switch
Fork-11 Tuning Fork Level Switch is specially designed for powdery and fine-grained bulk solids with the lowest density of 0.008g/cm³. Fork-11 offers maximum reliability in a wide application range.
Fork-11 Tuning Fork Level Switch is specially designed for powdery and fine-grained bulk solids, such as sands, fine raw materials in chemical industry, flours, salts etc., successfully handles lightweight media applications that are difficult to measure or detect like fine low density media with density of 0.008g/cm³. Fork-11 offers maximum reliability in a wide application range. For tall and narrow silos, Fork-11 with the suspension cable is also available.
Fork-11 Tuning Fork Level Switch probe is based on a tuning fork harmonic resonance. It utilizes piezoelectric devices to drive the fork to vibrate and detect the changes of vibration. The fork vibrates in resonant frequency when it is in air. Once the fork comes into contact with application medium, the vibration amplitude of the fork will decrease substantially. Output from the detecting piezoelectric device will decrease accordingly. An integrated circuit is designed to analyze the amount of decrease and output a switch signal. By reasonably increasing the area of tines and precisely adjusting harmonic resonance, Jiwei Fork-11 Tuning Fork Level Switch offers great reliability and sensitivity. Therefore, it makes Fork-11 the best level switch for ultra-low-density media.
● Reasonable design of tines and precisely adjusted of fork resonant frequency. Fork-11 can be used in light powders and flakes with bulk densities as low as 0.008g/cm³.
● Particularly suits for level measurement of powdery, fine-grained bulk solids, can effectively avoid buildup.
● With the suspension cable, Fork-11 can be applied in tall and narrow silo.
● Industry-leading performance for high temperature industrial environments, can tolerate process temperature up to 400℃.
● Strong self-diagnostic function helps to accurately locate the fault.
● Easy installation and maintenance free.
● With CE certificates, gas and dust Flameproof Enclosure and Intrinsic Safety certificates.
● Wetted parts are made of strong corrosion resistant material 316L.
| Applicable medium | Types of the Medium | powders or granular solids |
| Density | ≥0.008 g/cm³ | |
| Medium size | Max. 10mm | |
| Probe data | Vibration frequency | ～140Hz |
| Fork length | 150mm | |
| Switching Delay | When immersed | 0.5s |
| When laid bare | 1s | |
| Power supply | Relay | 20～253V AC/20～72V DC |
| Two-wire | 10～36V DC | |
| Max. power consumption | 8VA(AC)；1.5W(DC) | |
| Output | Relay | DPDT, 5A/253V AC/24V DC |
| Two-wire | 8mA/16mA， Alarm <2.3mA | |
| Installation conditions | Process pressure | -1～25bar |
| Process temperature | Regular temperature r: -50～150℃ High temperature: -50～250℃ Ultra-high temperature: -50～400℃ | |
| Ambient temperature | -40～80℃ | |
| Storage and transport temperature | -40～80℃ | |
| Cooling system data (for Ultra-high temperature only） | Air intake tube | 6×4 (Outer diameter 6mm) PU tube |
| Cooling air pressure | 0.8Mpa | |
| Min. cooling air flow rate | To be adjusted | |
| Overvoltage protection | Relay | Category III, class I |
| Two-wire | Category III, class II | |
| Certificates and approvals | Ingress Protection | IP66/IP67 |
| Explosion-Proof | Flameproof Enclosure: Ex d IIC T6～T1 Gb | |
| Intrinsic Safety: Ex ia IIC T6～T1 Ga | ||
| CE | LVD and EMC Certificates | |
| Materials | Housing | Aluminum alloy, , stainless steel |
| Ground terminal | 316L | |
| Process fitting | 316L, 316L coated PTFE | |
| Fork | 316L, 316L coated PTFE | |
| Process seal | Klingersil C-4400 |
● EPP and EPS processes in foam molding machines and plastic forming machines.
● Zircon sand and petroleum coke.
● Ultra-low density particles and powders.
● After spraying PTFE on the fork, it is especially suitable for fumed silica (SiO₂) level measurement. The density of fumed silica is as low as 0.01g/cm³, and the lowest detectable density of Fork-11 is 0.008g/cm³, which fully meets the measurement requirements of fumed silica working conditions.
