Features: Process Source/Measure/Simulate 0-20 mA and 4-20 mA DC current Simultaneously monitor mA and % of scale Adjustable manual and automatic output current ramp and step modes Built-in 24 V loop power supply eliminates the need for an external supply HART mode inserts 250 ohm resistor in series with loop power output General Purpose DCV, ACV, AC+DC, DCI, ACI, resistance, frequency, continuity measurement functions True RMS AC and AC+DC measurements 50,000-count, dual display dB, dBm, limits, peak-hold, REL (delta), MIN, MAX, and average math functions Isolated USB interface with operating software HFR (High Frequency Rejection) mode Dirt and water-resistant housing with rubberized protective case CAT III 1000 V / CAT IV 600 V protection The 394B Process Multimeter combines the capabilities of a mA loop calibrator with a full-featured True RMS multimeter in one package. Dedicated mA loop calibrator functions provide technicians and electricians with the tools required for testing and troubleshooting process control systems. Source and simulate industry standard 0-20 mA and 4-20 mA control loops using the adjustable DC current output.