
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.
Features:
Temperature compensated to provide repeatable alarm under varying process temperatures
Continuous diagnostics detect sensor fault
Non-linear mA output signal can be used for trending, diagnostics and repeatable flow/level indication
Detects minimum flow or presence / absence of flow
Easy / fast calibration
Excellent low flow sensitivity
Applications:
Pump protection
Cooling water / Cooling air
Chemical feed pumps
Relief valve monitoring
Lubrication systems
Exhaust flow monitoring
Options:
Hot tap retractable probe
Sanitary design
NACE construction
Window to view alarm status
Integral or remote electronics
Flow body for very low flow detection



