The SR2401 is alow-cost, reliable, thermocouple input two-wire transmitters for field or panel mounting in various industrial housings and enclosures. They provide a DC output current (4/20 mA) proportional to a thermocouple input. On model SR2401 the output is galvanically isolated from the input.
The SR2401 provides isolation by using a feedback VCO to develop a pulse train with a duty cycle proportional to the input signal amplitude. This pulse train is coupled through a pulse transformer to output circuitry, where the duty cycle data is converted to a 4/20 mADC output level proportional to the millivolt signal from the thermocouple.
Ranging is accomplished via a plug-in range card which characterizes the input to the desired thermocouple types and sets the temperature range and burnout protection (upscale and downscale). Cold junction compensation is provided by a solid state temperature sensor embedded in the thermocouple input terminal strip.
The output ZERO and SPAN controls are accessible through the top of the case. Terminations are made to screw terminal connectors on top of the case.
Test points located on the transmitter’s front panel allow verification of loop current value, using a millameter, without breaking the loop current.
All Wilkerson products are designed with RFI filters and lightning protection to reduce susceptibility to electrical noise and damage by lightning.
TYPICAL APPLICATIONS
Remote temperature data acquisition.
Elimination of ground loops and common mode signals.
Wilkerson Instrument Co. 800-234-1343
