GE DS3820STMA

ey Parameters

• Channels: 4 isolated analog inputs

• Sensor Types: NTC thermistor (10kΩ, 100kΩ, custom curves), PTC thermistor (silicon, platinum‑based), Pt100 RTD (2/3/4‑wire), Ni100 RTD, resistance (0–500Ω, 0–2kΩ, 0–10kΩ) – software‑configurable per channel

• Resolution: 24‑bit ADC

• Accuracy: ±0.05°C (thermistor/RTD, 25°C); ±0.2°C over –40°C to +70°C

• Excitation Current: Software‑selectable 0.1 mA, 0.5 mA, 1 mA (per channel)

• Linearization: Built‑in (Steinhart‑Hart for thermistors; polynomial for RTDs) – direct temperature readout

• Custom Sensor Support: User‑programmable R‑T curves (up to 64 points per channel)

• Diagnostics: Open‑circuit detection, short‑circuit detection, over‑range/under‑range, signal‑loss detection, per‑channel LED status

• Isolation: 1500 V RMS (field‑to‑backplane); 500 V RMS between channels (per‑channel isolation)

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

• Terminal Type: Screw‑type – per suffix “A”

• Power: 24 V DC backplane power, ≤4 W (plus external field supply)

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

Advantages

• Universal sensor support – accepts thermistors, RTDs, and resistance sensors; single module covers multiple sensor types.

• Direct sensor connection – eliminates external signal conditioners; reduces panel space and cost.

• Built‑in linearization – provides direct temperature readout in °C or °F; no scaling required.

• Custom sensor curves – supports user‑programmable R‑T curves for custom sensors.

• 24‑bit resolution – provides superior measurement fidelity.

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

• Software‑configurable per channel – sensor type, wire configuration, and excitation current independently settable.

• Automatic lead compensation – for 3‑wire/4‑wire RTDs, cancels lead resistance errors.

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

• Enhanced diagnostics – includes signal‑loss detection for proactive maintenance.

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

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

Applications

• HVAC systems – duct, return air, and room temperature monitoring with mixed sensor types

• Medical equipment – patient monitoring, incubator, and lab equipment with NTC thermistors

• Automotive – cabin temperature (thermistor) and motor winding (RTD) monitoring

• Industrial – motor winding temperature (thermistor/RTD) and general‑purpose monitoring

• Laboratory equipment – environmental chambers with mixed sensor types

• Food processing – cold storage and processing temperature monitoring

• Building automation – zone temperature sensing and energy management

• Chemical processing – pipeline and tank temperature monitoring

Competitor Comparison

The DS3820STMA is the universal temperature input module – supporting thermistors, RTDs, and resistance sensors in a single slot. Compared to dedicated thermistor‑only or RTD‑only modules, it offers maximum flexibility and reduces spare parts inventory (one module type replaces multiple). For applications with mixed sensor types, the DS3820STMA delivers the most versatile and cost‑effective solution.

Selection Tips

• Choose DS3820STMA when you need to measure multiple temperature sensor types (thermistors, RTDs, resistance) 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 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 custom thermistors, use the user‑programmable R‑T curve feature – supports up to 64 points per channel.

• Not suitable for thermocouples – use dedicated TC modules.

• Ensure your PLC/DCS can handle the temperature data format from DS3820STMA.

Precautions

• Sensor selection: Each channel must be configured for the correct sensor type (thermistor, RTD, or resistance) – ensure correct selection before operation.

• RTD lead resistance: For 2‑wire RTDs, lead resistance directly adds error – use 3‑wire or 4‑wire for accurate measurements. The DS3820STMA compensates for 3‑wire/4‑wire automatically.

• Thermistor lead resistance: Thermistors are typically 2‑wire; lead resistance directly adds error – keep leads as short as possible or calibrate to compensate.

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

• Custom curve programming: When programming custom R‑T curves, ensure accurate data points (minimum 16 points recommended for ±0.1°C accuracy).

• Wiring: Use shielded twisted‑pair cables; ground shield at module end only. Maintain separation from power cables.

• Signal‑loss detection: Requires minimum sensor impedance – very low‑impedance sensors may not trigger detection.

• Power sequencing: Apply backplane power before field power.

• Calibration: Perform periodic calibration using precision resistors or calibrated sensors to maintain accuracy.

• Spare: Keep one spare DS3820STMA for critical mixed‑sensor loops – the universal feature set may have longer lead times.