PR-21

Supported Applications

The Omega PR-21 series consists of RTD probes with integral M12 connectors designed for process control and test and measurement applications. These sensors feature an all-welded 316L stainless steel housing to provide a robust sensing element suitable for industrial environments.

Operating Conditions & Performance

The PR-21 series operates within a temperature range of -50 to 250°C (-58 to 482°F) at the sensing end, with a maximum limit of 85°C (185°F) at the connector. The sensors utilize Class A Pt100 or Pt1000 platinum RTD elements per IEC60751 Standard, offering an accuracy of ±0.15°C @ 0°C. Response time is specified as 3.5 seconds or less for a 63% response in water.

Regarding mechanical durability, the series is vibration tested to MIL-STD-202G, Method 204D, Test Condition A (10g's from 10 to 500 Hz) for probes that are 150 mm or 6" long or shorter. The product holds RoHS certification.

Key Performance Specifications

• Accuracy Class: IEC CLASS A (±0.15°C @ 0°C)
• Sensing End Range: -50 to 250°C (-58 to 482°F)
• Connector Temperature Limit: 85°C (185°F) Maximum
• Response Time: 3.5 Seconds or Less (63% Response in Water)
• Vibration Rating: MIL-STD-202G, Method 204D, Test Condition A, 10g's from 10 to 500 Hz

Configuration Options

The PR-21 series offers extensive configuration options for mounting threads, probe diameters, insertion lengths, and sensor elements. The integral electrical connection is a 4-Pin M12 Connector.

Mounting Threads & Process Connections

• No Mounting Thread: Available as straight probes (Model prefix A).
• NPT Threads: Options include ¼ NPT, ⅜ NPT, and ½ NPT.
• Metric Threads: M8x1 and M10x1 mounting threads are available.

Diameters & Lengths

• Standard Diameter: ¼" (with optional ⅛" diameter).
• Metric Diameters: M6 is standard; M4.5 and M3 options are available.
• Lengths: Standard overall length is 6.00 inch, with custom lengths available. Metric variants include specific insertion lengths such as 160 mm, 260 mm, and 360 mm.

Sensor Elements & Accessories

• Element Types: Pt100 or Pt1000 (Class A).
• Cables: M12CM-T24SSPC-SF-2 and M12CM-T24SSPC-RF-2 cables are sold separately.

Model Number Construction Notes

The model number follows the pattern: PR-21<variant>-3-<element>-A-<diameter>-<length>-M12-1. Specific ordering rules include:

• Diameters: Change "1/4" to "1/8" for ⅛" probes, or change "M6" to "M3" for 3 mm diameters (no additional cost).
• Elements: Change "100" to "1000" in the model number for Pt1000 elements.
• Inch Lengths: For lengths other than 6", change "0600" to the required length (e.g., 9" = 0900, 4½" = 0450); additional cost applies per inch greater than 6".
• Metric Lengths: For lengths longer than 360 mm, change "0360" to the required length in mm (e.g., 500 mm = 0500); additional cost applies per 25 mm increment.

Key Product Differences

Variants within the PR-21 series are distinguished by their mounting thread configuration and probe diameter. The model prefix indicates the specific combination:

• A Series: No mounting thread.
• B, C, D Series: Feature ½ NPT, ⅜ NPT, or ¼ NPT threads respectively (typically with 1/4" diameter).
• E and F Series: Designed for metric applications with M8x1 and M10x1 mounting threads.

The series supports both Pt100 and Pt1000 elements across these configurations, allowing selection based on resistance requirements. Probe diameters vary between ¼", ⅛", M6, M4.5, and M3 depending on the specific model code selected.