NI FP-RTD-122 FieldPoint Three-Wire RTD and Resistance Input Module

The NI FP-RTD-122 is an eight-channel input module for accurate three-wire RTD and resistance measurement in industrial data acquisition systems. It delivers precise temperature monitoring across a wide range with onboard linearization and configurable output units, making it ideal for applications requiring high accuracy and lead-wire error compensation.

– Technical Specifications

Input Characteristics
• 8 input channels
• True three-wire RTD configuration
• Platinum RTD compatibility: 100 Ω and 1,000 Ω (PT100, PT1000)
• Direct resistance measurement: 400 Ω and 4,000 Ω ranges
• Excitation current: 0.25 mA pulsed per channel
• 16-bit ADC resolution
• Input bandwidth: 3 Hz
• Filtering: 50/60 Hz common and normal mode noise rejection

Temperature Measurement
• Range: –200 to 850 °C (–328 to 1,562 °F, 73 to 1,123 K)
• Configurable output: °C, °F, or °K
• Built-in linearization for six TCR values: 3.750, 3.851, 3.911, 3.916, 3.920, and 3.928 mΩ/Ω/°C
• Update rate: 1.08 seconds per channel
• Accuracy: ±3 °C per Ω mismatch (100 Ω RTDs); ±0.3 °C per Ω mismatch (1,000 Ω RTDs) based on typical 10 m, 22 gauge copper lead wire with 5% resistance mismatch

Electrical & Environmental
• Overvoltage protection: 2,300 Vrms transient
• Optical bank isolation with double insulation to 250 Vrms
• No channel-to-channel isolation
• Power: 350 mW from network module
• Operating temperature: –40 to 70 °C
• Storage temperature: –55 to 85 °C
• Humidity: 10 to 90% non-condensing RH
• Vibration: 5 grms random, 5 g sinusoidal (10–500 Hz)

– Key Features

• Microcontroller-based linearization and scaling
• Three-wire measurement eliminates lead resistance effects
• 16-bit resolution for precise readings
• Wide temperature range operation
• LED indicators for power and ready status

– Typical Applications

• Industrial process temperature monitoring
• Precision thermal control systems
• Multi-point temperature data logging
• RTD-based sensor networks

– Compatibility & Integration

Mounts directly on FieldPoint terminal base (FP-TB-x). Compatible with National Instruments FieldPoint systems.