1. Product Parameters – Yokogawa SAI143‑S33

2. Product Overview

The SAI143‑S33 is a standard analog input module (no HART in “S” type), meant for the ProSafe‑RS safety I/O system. It handles 16 channels of current inputs (4‑20 mA) with module‑level isolation. Its design emphasizes stability, accuracy, and environmental tolerance. It is used to gather analog process signals (pressure, temperature, flow etc.) and feed them into safety logic and control modules. The “S33” style indicates certain environmental and performance standards: style code S3 or later typically includes compliance with ISA G3 environmental conditions, supports individual channel wiring flexibility, has specific power‑off behavior (high input impedance), etc.

3. Applications

The SAI143‑S33 finds its place in industrial applications where analog signals must be reliably monitored in safety or critical control loops. Typical use‑cases:

• Process safety systems (SIS) in chemical, petrochemical, oil & gas plants

• Fire & gas detection and interlock systems

• Power generation plants (steam, turbines, boilers) monitoring temperature, pressure, flow, level

• Refining operations where analog sensors feed into safety shutdown logic

• Large scale manufacturing / process plants with safety nodes / safety control units that must aggregate many analog inputs

• Environments subject to wide temperature and humidity variation; possibly corrosive atmospheres or high EMI, where module isolation and environmental robustness are critical

4. Advantages

Here are the main strengths of the SAI143‑S33:

• High Precision: ±16 µA accuracy over the key operating range (1‑23 mA) ensures tight measurement tolerances.

• High Input Impedance When Off: ≥ 500 kΩ when unpowered — reduces loading on sensor loops in fault/off conditions.

• Flexibility in Wiring: Each channel can be set to 2‑wire or 4‑wire, enabling compatibility with many field devices.

• Isolation: Module isolation to 1.5 kV AC between inputs and the safety/control system protects from ground loops, noise, and electrical interference.

• Environmental Robustness: Operates from ‑20 °C to +70 °C; wide humidity range; compliant with ISA G3 environmental standards.

• Dense Channel Count: 16 channels per module saves rack / cabinet space.

• Efficient Power Supply: Integrated transmitter power supply (in 2‑wire mode) allowing the module to provide power to sensors when needed.

• Reliable & Standardized: Uses a well‑understood, proven series in safety instrumentation; reduces variation, simplifies maintenance.

5. Brand & Series

• Brand: Yokogawa

• Series / Product Line: ProSafe‑RS Safety Instrumented System, particularly the SAI143 family of analog input modules. The “S” in S33 indicates “Standard” (i.e. no HART), “33” style code for environmental / performance standard.

6. Related / Same‑Series or Similar Models

Here are 5 models from the same series or very closely related, to compare or consider:

7. Other Popular Models from Same Brand

Here are 5 other well‑known / commonly used modules from Yokogawa that users often consider, from related series or analog / safety I/O: