RTD Assemblies + Thermowells

Resistance Temperature Detectors (RTDs) - Platinum - Elements and Assemblies

Part Numbering System

After locating a figure and part number in the below tables, you can fine tune the sensor for your application. If you require an American curve sensor and not the European curve, change the β€œE” to an β€œA”  in the part number. If you require a 500 Ω Β and not the standard 100 Ω sensor, change the β€œ11”  in the part number to β€œ51”. 1000 Ω sensors can be ordered by changing the β€œ11”  to an β€œ101”. Substitute any β€œX” and β€œY” characters with your length requirements. RTDs are provided in four wire configurations as standard. This is the most accurate configuration.

Note: if you are using a transmitter you may be only able to use a three wire sensor. This can be designated by changing the β€œ4” in the part number to a β€œ3”. Two wire RTDs can be specified by changing the β€œ4” with a β€œ2” in the part number.

The standard metal sheath for RTD elements are 1/4” diameter made of 316 stainless steel. Inconel 600 sheaths can be specified by changing the β€œ16”  in the part number to a β€œ09”.

Example part number: 4E164-11-24-12 four wire, European curve, 316 Stainless Steel 1/4 inch diameter sheath, 100 Ω ,Β  24” probe and leads overall, 12” probe.

Note: Richards standard RTDs have a maximum service temperature rating of 400Β°C (752Β°F).Β Β  Our high temperature RTDs have a maximum service temperature rating ofΒ  650Β°C (1202Β°F).Β Β  If you would like to specify this option, add a β€œH” after the curve designation letter (A or E) in the catalog number.

Need to order a Dual element or Assembly? - Insert β€œD” after the β€œE” in the catalog number.

Example:Β  4ED164-1-24-12

RTD Element Configurations

RTD elements are available as plain probes or they can be ordered with various mounting fittings or quick connect plugs. Order spring loaded elements for use in machined thermowell assemblies. Richards can manufacture Custom RTD's to your specific application.

Β X = Overall Length.Β Β Β Β Β Β  Y = Probe or insertion length.
Note: For an Inconel sheath (Alloy #9), substitute the β€œ16” in the part number with a β€œ9”.Β Β  Other special alloys also available.

p152 RTDs Pub 20170918-1
p152 RTDs Pub 20170918-2 SH Head
p152 RTDs Pub 20170918-1 Style A-2
p152 RTDs Pub 20180402-1 Style B-3
p152 RTDs Pub 20180402-1 Style C-4
p154 RTDs Pub 20170920 SFxx Text
p154 RTDs Pub 20170920 SFxx ESH
p155 RTDs Pub 20170919 SFxx PSH


  • 316SS 1/4” Diameter Sheath
  • European Curve Element
  • 100Ώ Resistance
  • Four Wire Lead Configuration
  • Max. Temp. 400Β°C (752Β°F)
  • High Temp. Option 650Β°C (1202Β°F)
  • Β Β± 0.04% resistance or Β±0.1Β°C Accuracy