Stanford Research PTC321

The Stanford Research PTC321 is a four-channel RTD input card for the PTC10 Programmable Temperature Controller. It delivers precision temperature measurement for 100 Ω Platinum RTD sensors across a range of -200 °C to 850 °C with ±30 mK accuracy. Each channel employs four-wire sensor configuration with dedicated 1 mA excitation current and current reversal to eliminate stray thermoelectric EMFs.

The card integrates into the modular PTC10 system, enabling flexible multi-card configurations supporting up to 16 input channels and 6 PID feedback control loops operating at 50 Hz sampling rate.

Technical Specifications

• Sensor Type: 100 Ω Platinum RTD (Pt RTD)


• Input Channels: Four independent channels


• Wiring Configuration: Four-wire per channel


• Excitation Current: 1 mA per channel with current reversal


• Temperature Range: -200 °C to 850 °C


• Accuracy: ±30 mK


• Noise: 2 mKrms at 10 samples/s


• Temperature Coefficient: 1.4 mK/°C


• Signal Filtering: Selectable 1-second and 10-second time constant digital low-pass filters


• Sensor Diagnostics: Open and short circuit detection


• Calibration: Dual-point calibration at 25 °C and 35 °C circuit board temperatures with microcontroller interpolation


• Temperature Resolution: 1 mK

Key Features

• Four-wire measurement eliminates lead resistance effects


• Current reversal cancels spurious EMFs for enhanced measurement integrity


• Modular design integrates with up to three additional I/O cards in PTC10 system


• Dual-temperature calibration compensates for thermal drift across operating range


• Low noise performance: 2 mKrms at standard sampling

Typical Applications

• Precision cryogenic and thermal research


• Industrial process temperature control requiring ±30 mK stability


• Multi-channel temperature monitoring in scientific instrumentation


• High-accuracy thermal stability applications across -200 °C to 850 °C range

Compatibility & Integration The PTC321 is designed exclusively for the Stanford Research Systems PTC10 Programmable Temperature Controller. The PTC10 system supports up to 16 total input channels, 6 PID control channels, USB and Ethernet interfaces, and data logging to removable USB flash media.