Thermatel® TD1/TD2 thermal dispersion switches, the popular choice for pump protection

Thermal dispersion switches play a vital role in safeguarding pumps across applications, from water to high-viscosity liquids. With sensor designs engineered for specific needs such as spherical tips, low-flow bodies, and high-temperature or high-pressure probes, they deliver exceptional adaptability. When paired with advanced electronics, AMETEK LMS/Magnetrol thermal dispersion switches provide reliable protection, making them a trusted solution for ensuring pump performance and longevity while reducing the risk of costly damage.

Across many industries, pumps represent a critical investment. From wastewater treatment and chemical processing through to food production and oil & gas operations, unplanned downtime or damage caused by running dry can result in significant cost and safety implications. Installing a reliable flow or level switch is therefore essential in extending pump life and ensuring safe, efficient operation.

The Thermatel® Model TD1/TD2 brings the latest in thermal dispersion technology to this challenge. Its advanced electronics provide continuous diagnostics with fault indication, automatic temperature compensation and a fast response time, making it one of the most dependable solutions on the market.

Operating Principle

The Thermatel sensor uses two RTD elements: one as a reference and the other heated above the process temperature. Electronics measure the temperature difference between them. This difference is largest in air and decreases when cooling occurs due to a change in media. Higher flow rates cause further reduction in the difference. A set point is configured so the switch alarms when the specified temperature difference is reached. At that point, the relay changes state, providing a reliable flow or media detection signal.

Key Features:

• Unique spherical tip design: highly sensitive for low-flow detection
• Continuous diagnostics: built-in fault indication for reliability
• Temperature compensation: maintains accuracy under process changes
• Fast response time: detects flow/level changes quickly
• Non-moving parts: minimises maintenance, increases durability
• Wide process compatibility: suitable for liquids, gases, and slurries

By combining robust sensor construction with advanced monitoring capabilities, the Thermatel TD1/TD2 ensures pumps are protected even in the most demanding environments. Whether the application involves detecting low flow in a cooling water line, preventing dry-run in a chemical dosing pump, or monitoring slurries in a processing plant, this thermal dispersion switch delivers accuracy and peace of mind.

Have a particular application / project in mind? We’d welcome a call on +44 (0) 1189 311 188, or email us now at info@ableinstruments.com