Level switches

What is a Point Level Switch

A point level switch is a level detection instrument that generates a switching signal when process material reaches a specific predetermined level inside a tank or vessel. Unlike continuous level transmitters that measure level across the full range of a vessel, a point level switch is designed for single-point detection triggering alarms, activating pumps, opening valves, or shutting down equipment when material reaches a high or low level set point.

Point level switches are the correct instrument selection for overfill protection, dry-run prevention, pump control, and high or low level alarm applications where a continuous level reading is not required and a simple on/off switching output is sufficient for the process control requirement.

Types of Point Level Switches Available at TTS

• Vibrating Level Switches : Use vibrating fork technology for reliable point level detection in liquids and bulk solids, unaffected by foam, turbulence, or changes in density. No calibration required after installation.
• Capacitive Level Switches :  Detect the presence or absence of both conductive and non-conductive materials including liquids, powders, and granular solids. Suitable for chemically aggressive and high-temperature environments.
• ERH Series Float Level Switches : Float-based point level switches for liquid detection in pressure vessels. Available with marine certifications including DNV-GL, LR, BV, and PRS for offshore and marine installations.

Accurate Level Detection for Demanding Applications

Level switches play a critical role in process automation, helping you detect and control liquid levels in tanks, vessels and pipelines. Whether you're preventing overflows, maintaining fluid consistency, or triggering alarms, our level switches offer the performance you can rely on.

At The Transmitter Shop, we supply reconditioned, new surplus and factory-sealed level switches from top brands like Applisens, Vega and TTS each rigorously inspected and tested to meet demanding industrial standards.

Our Level Switch Solutions Include:

• Vibrating Level Switches - Ideal for monitoring solids and liquids, these switches use vibrating probe technology for accurate detection even in foamy or turbulent conditions.
• Capacitive Level Switches - Suitable for both conductive and non-conductive materials, offering dependable operation in chemically aggressive or high-temperature environments.
• ERH Series Level Switches - Known for their robust design and reliable switching performance in fluid level control applications. The ERH Series is ideal for industries requiring compact, high-accuracy level sensing in challenging environments.

Need Help Choosing the Right Level Switch?

Not sure whether a vibrating, capacitive, or ERH Series level switch fits your application? Our experienced team is here to help. We'll guide you through product selection to ensure optimal performance for your specific process conditions.

Selecting the Right Point Level Switch for Your Application

The correct point level switch selection depends on the process media, vessel conditions, and the switching requirement of the application. The following guide covers the primary selection criteria for each switch type available at TTS.

Vibrating Level Switches

• Liquids, light bulk solids, powders, and granular materials where foam, turbulence, or density variation would affect float-based detection
• Applications requiring a maintenance-free, calibration-free point level switch with no moving parts
• Hygienic applications in food, beverage, and pharmaceutical industries requiring CIP and SIP compatible instruments
• Hazardous area installations requiring ATEX or IECEx certified point level switches

Capacitive Level Switches

• Both conductive and non-conductive liquids, powders, pastes, and bulk solids where other technologies are unreliable
• Chemically aggressive media requiring corrosion-resistant wetted materials
• High-temperature and high-pressure process conditions that exceed the operating limits of vibrating fork switches
• Applications involving material buildup or coating on the probe where standard vibrating fork performance degrades

ERH Series Float Level Switches 

• Clean liquid point level detection in pressure vessels where a simple, cost-effective float switch is sufficient
• Marine and offshore installations requiring DNV-GL, LR, BV, or PRS certified level switches
• Applications where the switch must operate without external power supply
• Side or top-mounted installations in storage tanks, bilge systems, and separator vessels

Point Level Switches for Hazardous Area Installations

Many industrial installations require point level switches certified for use in hazardous or classified areas where flammable gases, vapours, or combustible dust may be present. TTS supplies VEGA VEGASWING and VEGACAP point level switches with the following hazardous area certifications:

• ATEX European hazardous area certification covering Zone 0, Zone 1, and Zone 2 gas and dust classifications
• IECEx International hazardous area certification accepted across global installations
• FM and CSA North American hazardous area approvals covering Division 1 and Division 2 classified locations
• SIL Safety Integrity Level rated models available for use in safety instrumented systems compliant with IEC 61508

When specifying a point level switch for a hazardous area, the certification must match the area classification of the installation location. TTS can confirm the correct certified model for your zone or division classification before purchase.

Industries Using Point Level Switches

TTS supplies point level switches across the following industries where reliable, accurate level detection is critical to process safety and operational continuity:

• Oil and Gas: Overfill protection on crude oil storage tanks, high and low level alarms on separator vessels, produced water tanks, and offshore platform process vessels
• Chemical Processing: High and low level detection in acid storage, solvent tanks, reactor vessels, and chemical dosing systems where corrosion-resistant wetted materials are required
• Water and Wastewater Treatment: Pump control and overflow prevention in clarifiers, sump pits, chemical dosing vessels, and clean water reservoirs
• Food and Beverage: Hygienic point level detection in ingredient storage tanks, mixing vessels, and process equipment requiring CIP-compatible instruments
• Pharmaceutical: Level detection in purified water systems, solvent storage, and process reactors where contamination-free sensing is required
• Power Generation: High and low level alarms on boiler feed water tanks, condensate receivers, and fuel oil storage
• Cement and Bulk Solids: Point level detection in cement silos, clinker hoppers, and raw material storage bins where vibrating fork technology handles high dust concentration and uneven material surfaces

Frequently Asked Questions

What is the difference between a point level switch and a continuous level transmitter?

A point level switch generates a simple on/off switching signal when the process material reaches a specific predetermined level. It does not measure level across the full range of the vessel. A continuous level transmitter provides a variable output signal such as 4-20 mA that reflects the exact liquid level at any given time across the full measurement range. Point level switches are used for alarm, pump control, and overfill protection. Continuous transmitters are used for process control, inventory management, and applications requiring real-time level monitoring.

Can point level switches be used for bulk solids and powders?

Yes. Vibrating fork level switches and capacitive level switches are both suitable for bulk solid point level detection in silos, hoppers, and storage bins. Vibrating fork switches are the most common selection for bulk solid applications due to their resistance to false signals from dust, vibration, and material buildup. Capacitive switches are preferred for materials with varying dielectric properties or where probe coating is a concern.

Do point level switches require calibration after installation?

VEGA vibrating fork level switches are factory set and require no calibration after installation. The switching point is determined by the physical position of the switch in the vessel. Capacitive level switches may require a basic sensitivity adjustment on installation depending on the dielectric properties of the process media. ERH Series float switches operate mechanically and require no electronic calibration.

What output does a point level switch provide?

Point level switches provide a discrete switching output typically a relay contact (SPDT or DPDT), a transistor output, or a namur proximity switch output. This switching signal is wired to a PLC, DCS, or safety relay to trigger alarms, start or stop pumps, open or close valves, or activate other process equipment when the level set point is reached.

Are VEGA point level switches suitable for hygienic applications?

Yes. VEGA VEGASWING and VEGAPOINT series switches are available in hygienic versions with electropolished wetted parts, tri-clamp and varivent process connections, and FDA-compliant elastomer seals. These are suitable for CIP and SIP cleaning cycles in food, beverage, dairy, and pharmaceutical processing applications.