Newport 325 Temperature Controller

The Newport 325 Temperature Controller is a precision instrument for thermal management in laboratory, research, and industrial settings. It delivers stable temperature control through hybrid P-I regulation and dual independent PID loops, each with autotuning capability. The controller accepts six sensor types—thermistors, AD590 and LM335 IC sensors, diodes, RTDs, and thermocouples—enabling operation from 1.4 K (silicon diodes) to above 1,500 K. A 24-bit ADC with optical isolation and current reversal noise reduction ensures high-resolution measurements updated ten times per second.

– Technical Specifications

• Output Type: Bipolar, constant current source
• Maximum Current: ±2.5 A
• Compliance Voltage: >6 V
• Available Output Power: 15 W
• Current Limit Accuracy: ±10 mA
• Ripple/Noise (rms): <1 mA
• Short-Term Stability (10–30 min): 0.005°C
• Long-Term Stability (24 h): 0.01°C
• Temperature Display Range: −50.0°C to +150.0°C
• ADC Resolution: 24-bit
• Sensor Data Update Rate: 10 Hz

– Key Features

• Two independent control loops with separate current sources for each sensor input
• Hybrid P-I TEC control loop with independent PID autotuning per channel
• Support for up to 15 stored CalCurves® (200-point) or user-defined curves in non-volatile memory
• SoftCal® algorithm for silicon diode and platinum RTD curve generation
• Temperature limit safeguards disable channels upon exceedance
• Control Loop 1: 25 W continuous power to 50 Ω or 25 Ω heater loads
• Optically isolated sensor inputs with current reversal to eliminate thermal EMF errors

– Sensor Compatibility

• Thermistors (Constant R mode)
• AD590 and LM335 IC sensors (Constant T mode)
• Diodes (down to 1.4 K)
• RTDs including Cernox™ and platinum (down to 2.0 K)
• Thermocouples (operation above 1,500 K)
• Constant ITE mode for thermoelectric cooler control