• Provides DC Output Proportional to any Thermocouple Input**
• Fully Isolated Input / Output (SR2401)
• Unlimited Choice of Input Ranges via Interchangeable Range Cards (Within specified range limits)
• Reverse Polarity-Protected
• Upscale or Downscale Burnout Protection
• Test Points for Loop Current Monitoring without Breaking Loop Circuit
• 50 mm Diameter Case - 33 mm Mounting Hole Spacing
• NEMA-4 Connection Head and Explosion-Proof Housing Available
• Low Cost
• 5 Year Warranty

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.

INPUT RANGE select any type thermocouple (min span 5 mV) INPUT IMPEDANCE 10 megohms OUTPUT RANGE 4/20 mA Current limited = 35mA ISOLATION (SR2401) Output / Input 1000 Volts RMS sinewave MAX LOAD RESISTANCE = [(V supply - 10)/20 mA] kilohms RESPONSE TIME Step Change 250 ms for 99% of final value ACCURACY ±0.1% of span

LINEARITY Better than ±0.05% of span (mV) (input to output) COMMON MODE REJECTION 120 dB, DC to 60 Hz OPERATING TEMPERATURE -13°F to 176°F / -25°C to 80°C TEMPERATURE STABILITY ±0.01% of span per°C POWER 10-36 VDC, polarity-protected SUPPLY VOLTAGE EFFECT 0.02% of span max,10-36 VDC