Tuning Fork Level Switch

The Tuning Fork Level Switch utilizes piezoelectric crystals to provide consistent vibrations on the fork. In case the fork makes contact with the process fluid, the vibration frequencies change and enable the switch to measure the set level precisely.

Thanks to its small fork size, it can be easily installed in cramped spaces and provide reliable point level measurement.

The switch is applicable for either liquid or fine bulk solids, and can therefore find application in many industries.

Available in SS304 material and either threaded or flanged designs, some of the selected versions can be provided with an intrinsically safe or flameproof certification.

• Detects liquid level using vibrating tuning fork technology.
• No mechanical moving parts for maintenance-free operation.
• High and low fail-safe modes.
• Field-adjustable sensitivity for different liquid densities.
• Short fork design minimizes installation space.
• Replaceable electronics cassette for easy servicing.
• Withstands static electricity and lateral loads.
• Intrinsically safe construction for industrial applications.

• Application: Liquids
• Specific Gravity: Minimum 0.5 g/cm³
• Operating Temperature: -10°C to 80°C
• Power Supply: 220 VAC (Optional: 110 VAC, 24 VAC, 24 VDC)

Tuning Fork Vibration

In the Tuning Fork Level Switch, piezoelectric components are used to sustain the tuning fork vibration continuously at the natural frequency of vibration in the absence of the process material.

Normal Operating Condition

While in air, the tuning fork vibrates freely. The electronics continuously detect this vibration and set this as the reference normal operating condition.

Detection of Material Presence

As the process material approaches the fork, the vibration of the fork gets damped. This is immediately sensed by the electronic circuit.

Signal Processing

Comparison of the change in vibration with the predetermined reference value is made by the electronics in order to find out whether the fork is covered with process material.

Switching and Control Output

As soon as the preset level is reached, the state of the output relay is switched to indicate this situation and signals are sent to the PLC/controller for alarm generation, pump switching, valve control, etc.

Dimensional & Construction Options

• Standard Fork Probe Length: 110 mm mechanical vibration blade profile.
• Short Fork Level Switch Technology: Low-profile sensor design configured for minimized pipeline protrusion.

Mechanical & Material Options (MOC)

• Sensing Element Material: High-grade SS304 stainless steel assembly.
• Internal Drivers: Dual integrated piezoelectric resonant elements.

Process Connections

• Threaded Ports: 1” NPT Male standard connection.
• Flanged Connection Options: Special industrial adapter flanges built to size requirements.

Operational & Process Limits

• Medium Thermal Boundaries: Designed to handle active process conditions from -10°C up to 80°C.
• Material Density Threshold: Suitable for fluids and bulk solids with a minimum specific gravity of 0.5 g/cm³.
• Mechanical Safety Feature: Rigid structural construction rated to withstand static electricity and fierce lateral loads.

Power Supply Configurations

• Primary Voltage Input: Standard 220 VAC module.
• Alternative Voltage Input Cassettes: 110 VAC, 24 VAC, or 24 VDC.

Electronic Switching & Signal Outputs

• Electrical Interfacing Port: M20 x 1.5 standard connection thread.
• Output Contacts: Potential-free Single Pole Double Throw (SPDT) relay rated at 220 VAC, 5A.
• Safety & Control Modes: Field-adjustable sensitivity control module paired with selectable High/Low fail-safe protection.
• Safety Class Architecture: Replaceable electronic cassette configurations certified as intrinsically safe.

Level Detection: Tuning Fork Level Switch operates on the principle of vibration technology, hence providing reliable level detection despite the presence of foam, scale, or any process changes that might affect other level sensors.

Automation: Models with SPDT relay output can be readily installed in the PLC system for alarm, pump, and other process control operations.

Sturdy Build: It is built using SS304 materials and is thus suitable for heavy-duty industrial use especially with liquid, slurry, and fine powder media.

Multiple Connection Options: It comes in multiple connection process options including flanged.