Vibrating tuning fork level switches for dependable point-level detection, high / low alarms and pump or process interlocks in tanks, vessels and selected bulk-solid duties.
Tuning Fork Level Switches are designed for reliable point-level detection of powders, granules and bulk solids in tanks, silos, bins and hoppers.
The vibrating fork operates at a fixed frequency. When the fork is covered by material, the vibration changes and the electronics switch the relay output for high-level alarm, low-level detection or process interlocking.
The self-cleaning fork design helps reduce material build-up, while selectable fail-safe and sensitivity settings support reliable operation across different applications. Weatherproof and flameproof enclosure options are available for industrial installations.
How it works
Working Principle
The sensing fork is continuously driven at its resonant frequency. Contact with liquid or bulk material changes the vibration, and the electronics convert that change into a relay switching signal.
01
Fork vibrates freely
The uncovered fork oscillates at its normal resonant frequency under electronic excitation.
02
Material covers the fork
Liquid, powder or free-flowing solid changes the vibration amplitude or frequency when it reaches the sensing point.
03
Relay changes state
The electronics detect the change and operate the DPDT relay according to the selected high- or low-level fail-safe mode.
At a glance
Key Highlights
Maintenance-free electronic vibrating fork design
Reliable operation in foam and powder applications
Self-cleaning fork design reduces material build-up
Selectable Hi / Lo fail-safe and sensitivity settings
Vertical or horizontal installation
Range summary
Technical Specifications
Values below summarise the product family. Open an individual product for its complete model and variant data.
Power Consumption
3 W
Ambient Temperature
-40°C to 60°C
Process Temperature
-40°C to 130°C
Fork Length
100 to 3000 mm
Mounting Connection
1″ BSP / NPT (M); customised available
Cable Entry
M20 × 1.5
Relay Output
DPDT, 5 A, 230 VAC / 24 VDC
Minimum Material Density
0.7 g/cm³
Response Time
0.6 s operate / 1–3 s reset
Vibrating Frequency
350–370 Hz
Enclosure
Weatherproof / Flameproof
Typical use
Applications
Powder and granular material level detection
High- and low-level alarm in silos and hoppers
Dry-run protection and empty detection
Overflow prevention in storage vessels
Level detection in bins, tanks and process vessels
Applications with foam, dust or material build-up
Selection confidence
Why Choose Kuncham Controls?
Reliable point detection
Vibration-based sensing provides a clear switching response for compatible powders, granules and bulk solids.
Reduced material build-up
The self-cleaning fork design helps reduce material accumulation around the sensing element.
Fail-safe flexibility
Selectable Hi / Lo fail-safe and sensitivity settings support overfill, empty and interlock duties.
Flexible installation
Standard, flanged, extended-length, Tri-Clover, cooling-fin and PTFE-coated configurations support varied applications.
Support
Questions & Answers
Which materials can the Tuning Fork Level Switch detect?
It is intended for compatible powders, granules and bulk solids, with a listed minimum material density of 0.7 g/cm³.
Can it operate where foam or dust is present?
The design is intended to remain reliable in foam, powder and dusty applications when correctly selected and installed.
Can it be installed horizontally?
Yes. Vertical or horizontal installation can be selected according to the required switching point and vessel arrangement.
Which fork lengths are available?
Fork lengths from 100 mm to 3000 mm are available, including extended-length configurations.
What information is needed for selection?
Provide the material, density, process temperature, mounting position, insertion length, connection, enclosure, supply and required fail-safe action.
