Thermatel® Model TD1/TD2 Flow/Level/Interface Switches
Thermatel Model TD1/TD2 flow/level/interface switches provide a new level of performance and reliability not found in previous switches. Continuous diagnostics with fault indication, temperature compensation, narrow hysteresis and fast response time make the TD1/TD2 the latest in thermal dispersion switch technology.
Measurement Principle:
The Thermatel sensor consists of two RTD elements. One is the 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, then decreases when cooling occurs due to a change in media. An increase in the flow rate further decreases the temperature difference.
The set point is adjusted for the switch to alarm at the desired temperature difference. Once the set point is reached, the relay will change state.
