The Metri IC-LPS is a versatile, adjustable thermal flow switch designed for reliable flow monitoring across a wide range of industrial liquids. Based on thermal dispersion technology, it has no moving parts, ensuring maintenance-free operation and long-term durability even in demanding applications. It provides both visual and electrical alarm signals when flow rates rise above or fall below the user-defined set point.

Working Principle

The IC-LPS uses thermal dispersion technology to detect flow. A heated sensor is cooled by the passing fluid; the rate of cooling is proportional to the flow velocity. An internal circuit compares this to a reference sensor and triggers the switch output when the set point is reached. This technology is unaffected by changes in fluid pressure, temperature, or viscosity, providing reliable and repeatable switching.

Key Features

• Wide Flow Range & Turndown: Covers 0.5 to 1200 L/min with a high turndown ratio of up to 30:1, offering flexibility for diverse applications.
• Extreme Temperature & Pressure Capability: Operates in media temperatures from -40°C to +350°C and withstands pressures up to 100 bar, suitable for demanding thermal systems.
• Robust Construction: Standard 304 stainless steel body (316 optional), with tungsten carbide shaft and sapphire bearings for exceptional durability.
• Flexible Configuration: Available with threaded (BSPP/BSPT) or flanged (DIN/ANSI) connections, and can be mounted locally or remotely.
• ATEX & IECEx Certified: Certified for use in potentially explosive atmospheres, expanding its application range.
• Visual & Electrical Indication: Features 2x LED indicators for local status and a SPDT relay output for integration into control systems.

Technical Specifications

• Wetted Materials: Body: 304/316 SS; Rotor: SS; Shaft: Tungsten carbide; Bearings: Tungsten carbide / sapphire; O-ring: Buna N (standard), Viton (optional).
• Pressure Drop: Typically <125 mbar at maximum flow rate (standard ranges without flow restrictor).
• Switch Voltage: Nominal 24 VDC (Min 8 VDC - Max 30 VDC).
• Switch Current: 12mA in alarm state, 8.6mA in non-alarm state (must be externally fused at 50mA).
• Relay Output: SPDT, voltage-free contact; Max Voltage: 175V; Max Current: 250mA.
• Installation: Horizontal or vertical (flow upward), pipe must be full.
• Calibration: Can be calibrated for 5 or 10 points; annual recalibration recommended for optimum accuracy.

Applications

The IC-LPS is ideal for flow/no-flow alarm and pump protection in a wide range of industries, including:

• Machine tool coolant flow monitoring.
• Hydraulic oil circuits.
• Reverse osmosis (RO) water systems.
• High-pressure and high-temperature water systems.
• Chemical injection and processing.
• Fuel and oil transfer lines.