PR 3331 Loop-Powered Temperature Converter

The PR 3331 Loop-Powered Isolated Temperature Converter is a precision signal conditioning device for converting industrial temperature sensor inputs into reliable isolated 4–20 mA current loop outputs. Ideal for process automation, control systems, and industrial instrumentation, the 3331, from PR electronics, supports standard temperature sensors including Pt100 RTDs and thermocouples (TC J & K). Its loop-powered design eliminates the need for external power, thus simplifying installation and reducing infrastructure costs.

• The PR 3331 is a loop-powered temperature converter that measures a standard Pt100, thermocouple (TC) J and K temperature sensor, and provides an isolated passive analog current output signal.
• High 2 port isolation provides surge suppression and protects the control system from transients and noise.
• The 3331 can mount in the safe area or in Zone 2 / Division 2 hazardous areas.
• Features approval for marine applications.

PR 3331 Loop-Powered Temperature Converter

Featuring excellent conversion accuracy better than 0.05 % of span and selectable fast response times as low as <30 ms, the PR 3331 Loop-Powered Temperature Converter ensures accurate, real-time temperature data for critical process monitoring. Robust galvanic isolation (2.5 kVAC) and compliance with NAMUR NE21/NE43 standards deliver superior noise suppression and sensor error handling, even in harsh electrical environments.

• Flexibly loop powered by 5.5 to 35 VDC via connectors.
• < 30 ms fast response time with simultaneous sensor error detection when selected.
• Selectable 300 ms response time when signal dampening is necessary. 
• Selectable internal/external CJC.
• Excellent conversion accuracy in all available ranges, better than 0.05% of span.
• Meeting the NAMUR NE21 recommendations, the 3331 provides top measurement performance in harsh EMC environments.
• This loop-powered temperature converter meets the NAMUR NE43 standard defining out of range in addition to sensor error output values.
• All terminals feature protection against overvoltage as well as polarity error.
• High galvanic isolation of 2.5 kVAC.
• Excellent signal/noise ratio of > 60 dB.

Easy Mounting, Installation, and Programming

The slim 6.1 mm DIN-rail housing enables high-density mounting in control panels, supporting up to 163 units per meter without gaps. Easy configuration via DIP switches provides access to more than 1000 factory-calibrated temperature ranges. Furthermore, selectable internal or external cold junction compensation enhances flexibility for thermocouple applications.

Built for industrial reliability, the PR 3331 operates across a wide temperature range -13 to 158˚F (-25 to 70˚C) and offers certification for Safe Areas as well as Zone 2/Division 2 and marine applications. Thus the 3331 loop-powered temperature converter is a versatile choice for industrial temperature measurement and process control.

• Selectable DIP-settings for easy configuration of more than 1000 factory calibrated measurement ranges.
• The narrow 6.1 mm housing allows up to 163 units to be mounted per meter of DIN rail, without any air gap between units.
• Wide ambient temperature range of -13 to 158˚F (-25 to 70˚C).