CalFlo™ CFTM Thermal Mass Flow & Temperature Meter

Description

Flow and Temperature. One Smart Sensor.

The CalFlo™ CFTM Thermal Mass Flow and Temperature Meter represents a significant step forward in insertion-style flow sensing. Built on over 30 years of thermal flow expertise and paired with modern microprocessor intelligence, the CFTM simultaneously measures both liquid flow velocity and process temperature from a single instrument. This dual-measurement capability reduces installation complexity and the number of sensing points required in a system, making it a practical and cost-effective solution for process monitoring applications.

The standout feature of the CFTM is its patent-pending auto-self-calibration system. Unlike conventional thermal flow meters that drift over time as temperature conditions change, the CFTM continuously compensates for temperature variation without any manual intervention. This means there is no need for scheduled recalibration visits or expensive service contracts — the meter is designed to maintain its accuracy over many years of continuous operation, living up to its description as a true set-it-and-forget-it instrument.

Two interface options are available to suit different system requirements. The CFTM-1 provides two independent linear 4-20 mA outputs, one for flow and one for temperature, for straightforward integration with standard analog control systems and PLCs. The CFTM-2 uses RS-485 Modbus RTU communication, and adds a totalizing flow counter along with independently adjustable high and low setpoint switches for both flow and temperature, making it the better choice for more sophisticated monitoring and control applications.

The CFTM handles oil and water-based liquid applications across a velocity range of 0.25 to 10 ft/sec with autoranging, and withstands static pressures up to 1,400 psi. The housing is constructed from glass-fibre reinforced PBTP (Ultradur) and is rated IP65. The standard sensor probe is 303 stainless steel, with optional probes available in 316 stainless steel, titanium, Hastelloy C4, and Hastelloy C22 for more aggressive process media. Connection is via a 1/2-inch NPT thread and M12 plug, and the unit is operational within approximately 10 seconds of power being applied.

Installation follows standard insertion meter best practice: the probe tip should be fully immersed in liquid at all times, with the preferred location being a vertical discharge line or the side of a horizontal pipe to avoid air pockets and cavitation. A minimum of 5 pipe diameters of straight pipe upstream and 3 downstream of any fittings is recommended, with at least 15 pipe diameters of clearance from any pumps.