GE DS3820PMM

Key Parameters

• Channels: 4 configurable analog inputs (per-channel sensor type selection)

• Sensor Types:

  • RTD: Pt100 (2/3/4-wire), Ni100 (2/3/4-wire)

  • Thermocouple: J, K, T, E, R, S, B, N

• Resolution: 24-bit ADC

• Accuracy:

  • RTD: ±0.05°C (Pt100, 25°C); ±0.15°C over –40°C to +70°C

  • Thermocouple: ±0.04% + ±0.4°C (K-type, 25°C)

• Excitation Current (RTD mode): Software-selectable 0.1 mA, 0.5 mA, 1 mA

• Cold-Junction Compensation: Built-in per channel (thermocouple mode)

• Lead Compensation: Automatic for 3-wire/4-wire RTDs

• Diagnostics: Open-circuit detection, short-circuit detection, over-range/under-range, CJC sensor fault, per-channel LED status

• Isolation: 1500 V RMS (field-to-backplane); 500 V RMS between channels

• Sampling Rate: Up to 50 Hz per channel (with 50/60 Hz noise rejection)

• Power: 24 V DC backplane power, ≤3.5 W

• Operating Temperature: –40°C to +70°C

• Terminals: Screw-type (suffix-dependent)

Advantages

• Universal sensor support – accepts both RTDs and thermocouples; single module covers all common temperature sensors.

• Per-channel configurability – each channel independently set for RTD or thermocouple type; no hardware changes required.

• 24-bit resolution – provides highest precision for all temperature measurements.

• Per-channel isolation – 500 V between channels; prevents ground loops and cross-channel interference.

• Built-in CJC – for thermocouples; no external reference needed.

• Automatic lead compensation – for 3-wire/4-wire RTDs; cancels lead resistance errors.

• Built-in linearization – provides direct temperature readout in °C or °F.

• Open/short detection – detects broken wires or sensor shorts instantly.

• Hot-swappable – replace without rack power-down.

• Reduced spare parts – one module type covers multiple sensor types.

Applications

• Mixed-sensor temperature monitoring – plants with both RTD and thermocouple sensors

• HVAC systems – duct temperature (RTD) and flame monitoring (thermocouple)

• Pharmaceutical manufacturing – reactor (RTD) and sterilization (thermocouple) temperature control

• Food processing – oven (thermocouple) and cold storage (RTD) temperature profiling

• Power generation – bearing (RTD) and turbine exhaust (thermocouple) monitoring

• Chemical processing – pipeline (RTD) and reactor (thermocouple) temperature control

• Research & development – flexible temperature measurement with multiple sensor types

Competitor Comparison

The DS3820PMM is the universal temperature input module – supporting both RTDs and thermocouples in a single slot. Compared to dedicated Pt100 or TC modules, it offers maximum flexibility and reduces spare parts inventory (one module type replaces two). Against competitor universal modules, the DS3820PMM offers superior per-channel isolation and 24-bit resolution at a competitive price. For applications with mixed temperature sensor types, the DS3820PMM delivers the most versatile and cost-effective solution.

Selection Tips

• Choose DS3820PMM when you need to measure both RTD and thermocouple sensors on the same module – ideal for mixed-sensor applications.

• Perfect for reducing spare parts inventory – one module covers multiple sensor types.

• Verify the sensor type and wire configuration for each channel – software-configurable per channel.

• For RTDs, use 3-wire or 4-wire for accurate measurements (2-wire adds lead resistance error).

• For thermocouples, use the correct extension wire type – standard copper wire introduces errors.

• Ensure your PLC/DCS can handle 24-bit data resolution from the DS3820PMM.

Precautions

• Sensor selection: Each channel must be configured for either RTD or TC mode – ensure correct selection before operation.

• RTD wiring: For 2-wire RTDs, lead resistance directly adds error – use 3-wire or 4-wire for accurate measurements. The DS3820PMM compensates for 3-wire/4-wire automatically.

• Thermocouple wiring: Use the correct thermocouple extension wire (same type as sensor) from field to module.

• CJC placement: For thermocouple measurements, position the DS3820PMM away from drafts and heat sources – CJC errors affect accuracy.

• Excitation current (RTD): Higher currents (1 mA) produce self-heating errors – use 0.1 mA or 0.5 mA for sensitive sensors.

• Wiring: Use shielded twisted-pair cables; ground shield at module end only.

• Power sequencing: Apply backplane power before field power.

• Calibration: Perform periodic calibration using precision sources to maintain accuracy.

• Spare: Keep one spare DS3820PMM for critical temperature loops – the universal feature set may have longer lead times.