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PR-21
RTD Probes with Mounting Threads and M12 Connectors
Models In Stock
- Integral 4-Pin M12 A-Coded Male Connector for Easy Installation. An M12 Extension Cable is Required for Installation.
- Available With a Variety 316L SST Threaded and Non-Threaded Housings
- Pt100 or Pt1000 Class A, 4-Wire Platinum RTD Elements per IEC60751 Standard
- Available with 1/4", 1/8", 6mm and 3mm Probe Diameters and a Wide Variety of Standard Lengths
PR-21
From
C$
180.63
Models In Stock
Product Overview
- Color Code Standard ANSI
- Connector Temperature, Max 85 °C
- Connector Temperature, Min 0 °C
- Electrical Connection M12 4 pin Male
- Number of Wires 4
- Process Temperature, Max 250 °C
- Process Temperature, Min -50 °C
- Response Time 3.5 sec
- Response Time Note Fast Response Time (3.5 Seconds or Less 63% Response in Water)
- Series ID PR-21
- Sheath Material 316L Stainless Steel
- Temperature Sensor Type RTD
- Thermocouple Type N/A
- Vibration Vibration Tested to MIL-STD-202G, Method 204D, Test Condition A, 10g’s from 10 to 500 Hz (150 mm or 6" Long or Shorter)
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.
PDFs & Manuals
Accessories
accessories
Show Ratings & Reviews
Rated 5 out of
5
by
skip77j from
rtd
great quality, very accurate, and the quick disconnect feature makes swapping them out a breeze.
Date published: 2021-06-21
Rated 5 out of
5
by
djfs from
What we needed!
Exactly what we were looking for. Fair pricing and quick delivery.
Date published: 2026-03-01
Rated 5 out of
5
by
Chris Lanning from
Everything you want from an RTD
Simple, accurate, and reliable. I use these for all dirty air or bulk biomass applications
Date published: 2025-01-22
Rated 5 out of
5
by
Vicki Brown from
these connect really well
easy connection into the RTD and the sensor hooks up great
Date published: 2024-12-05
Rated 5 out of
5
by
GregO from
Direct Replacements
These RTD's have great build quality and work well. They are offered in multiple wiring schemes, allowing them to be used as direct replacements parts for products like Meriam MDT500 integrated laminar flow element devices.
Date published: 2023-04-06
Rated 4 out of
5
by
Anonymous from
Good RTD
Good sensor overall. The shaft can be sealed to <10E-5 TorrL/s helium with an 1/8 inch Swagelok bored through tube fitting. Be careful not to bend the shaft though, the 1/8 inch is pretty delicate.
Omega's mating cable is also pretty good but I wish they offered a shielded version with a metal connector.
Date published: 2020-05-22
Could this be used in a flow apparatus to measure temps from -40F-140F with an accuracy of 0.5% full scale?
Thank you for your inquiry Pipeline Engineer. Yes you can use this sensor to measure the temperature of the flow stream. This probe has an accuracy of Class A = ±(0.15 + 0.002*t)°C or 100.00 ±0.06 O at 0ºC. Here is the link for more information about the accuracy of a Class A RTD: https://www.omega.com/en-us/resources/rtd-hub
Date published: 2022-09-19
Okay I saw the option 1 & 2 diagram that but where’s pin 1, 2, 3 & 4 on the probe located. If only hooking up a 3 wire probe what wire do I not connect. Sorry not much information on the datasheet.
On the datasheet wiring diagrams you can see that 2 wires are common on each side of the PT100 symbol. If you only have a 3 wire input instrument you can just leave one wire from either side unconnected. If you are unsure you can always measure point to point on the wire to make sure the PT100 is located correctly per your instruments wiring diagram.
Date published: 2020-04-03
What is the pressure rating for the 1/2" NPT probe?
Thank you for you inquiry. Unfortunately this device doesn't have pressure rating.
Date published: 2020-11-16
I'm looking at the product details for this probe; Vibration Resistant Platinum RTD (PT100) Sensor with M12 Connector and Mounting Thread, Item# PR-21B-3-100-A-1/4-1200-M12-1. And can't find the wiring diagram for it
If you click on Datasheet(PDF) under the bullets on the product page there is a wiring diagram for both available options.
Date published: 2020-04-01
What is the resistance of the RTD at its temperature extremes? What is the temperature coefficient?
Thank you for your inquiry Anonymous. The resistance of this RTD at any temperature is 100 ohms. The alpha value for a Pt100 RTD like the PR-21D-3-100-A-1/8-0600-M12-1 is 0.00385.
Date published: 2022-09-19
How I can represent this product PR-21A-3-100-A-1/8-0475-M12-1 as a AutoCAD drawing? Especially there are 4 pin, Could you name it please?
Omega does not provide CAD drawings of it's products so send a request to temp@omega.com to see if any dimensions of the probe needs to be discussed in greater detail.
Date published: 2022-07-25
Can these be used without a thermowell using compression fittings? What would the pressure rating be for that type of application?
You can use a Compression fitting to seal the PR-21 series into a process however Omega does not specify a pressure rating.
Date published: 2020-04-01