Thermatel? TD1 and TD2 Series Flow/Level/Interface Switches

Product Description:

The Thermatel? TD1/TD2 series flow/level/interface switches offer a new level of performance and reliability not previously available in switches. With continuous diagnostics including fault indication, temperature compensation, narrow hysteresis, and fast response time, the TD1/TD2 represents the latest generation of thermal dispersion switches.

Applications:

Chemical, crude oil processing, natural gas processing, nuclear power, water and wastewater treatment, power generation, petroleum refining, pulp and paper.

Features:

(1) Temperature compensation provides repeatable alarms at different process temperatures;

(2) Continuous diagnostics detect sensor failures;

(3) Non-linear analog output signal for trending, diagnostics, and repeatable flow/level indication;

(4) Detects minimum flow, or presence/absence of flow;

(5) Extremely low flow rate detection;

(6) Simple calibration/installation.

Operating Principle:

(1) The THERMATEL sensor contains two RTD elements. One serves as a reference, and the second is heated to a temperature above the process temperature. The electronics detect the temperature difference between the two elements. The temperature difference is greatest in air and decreases as cooling occurs due to changes in the medium. Increased flow further reduces the temperature difference.

(2) The setpoint is adjusted to trigger an alarm at the desired temperature difference. Once the setpoint is reached, the relay changes state.