Resistance Temperature Detectors have achieved a well deserved reputation in the industry for their superior stability and accuracy. The result makes these devices well suited for a wide variety of applications. A Resistance Temperature Detector (RTD) senses heat based on the principle that a change in temperature results in a corresponding change in the resistance of a wire. The hotter the wires become, the larger or higher the value of their electrical resistance. RTDs are among the most precise temperature sensors available. The RTD can be comprised of many different termination styles as seen on the following pages. The RTD element is manufactured by winding a wire of plating a film on a ceramic or glass core. Usually RTDs are provided encapsulated in probes for temperature sensing and measurement with an external indicator, controller or transmitter, or enclosed inside other devices where they measure temperature as a part of the device's function, such as a temperature controller or precision thermostat. www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com 1-800-727-5646 85 Thermo-Couple Products Co. 85

The advantages of using RTDs are numerous. They offer high accuracy, repeatability, and stability. Another advantage is that cold junction compensation is unnecessary. Here is a brief summary of some of the advantages and disadvantages of both thermocouples and RTDs. RTD Selection Just as thermocouple selection is based on the intended application, RTDs are selected in the same manner. The response time and operating environment such as temperature and atmosphere are factors as well as the length of service. RTDs are available in a variety of combinations, the most commonly used material is platinum....

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com Thermo-Couple Products Co. 1-800-727-5646 86 RTD Standards There are several RTD standards set by various organizations throughout the world. These specifications are not identical and readout instrumentation must be adjusted for the specific standard of the RTD used with that equipment. Differences in the alpha values of these standards can cause errors in measurement of an RTD if one standard is connected to the instrumentation of another standard. Organization Standard Alpha (Coefficient) Nominal Resistance (ohms) at 0°C...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com 1-800-727-5646 87 Thermo-Couple Products Co. 87 303 - A - 100 - F - 5 - 3 - 304 - 0 RESISTANCE TEMPERATURE DETECTORS Series 303 • Superior Stability, Repeatability and Accuracy • Vibration and Shock Resistant • Industry Standard 3-Pin Quick Disconnect • Standard Resistance Value 100 Ohms at 0°C, Others Available • Standard Resistance Tolerance of ±0.1% at 0°C ! Metric Ord e rs Welcome Place an mm in the appropriate selection box: 100 mm Enter a selection for each item, please fax your inquiry to TCP. 303 - Example: - - -...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com Thermo-Couple Products Co. 1-800-727-5646 88 RESISTANCE TEMPERATURE DETECTORS Series 404 • Superior Stability, Repeatability and Accuracy • Vibration and Shock Resistant • Industry Standard 3-Pin Quick Disconnect with Teflon flexible Lead Wire • Standard Resistance Value 100 Ohms at 0°C, Others Available • Standard Resistance Tolerance of ±0.1% at 0°C Enter a selection for each item, please fax your inquiry to TCP. 404 - Example: IMMERSION LENGTH “L” Specify in inches CODE TERMINATION STYLE 10 40 70 111 2-pin for 2 wire 3"...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com 1-800-727-5646 89 Thermo-Couple Products Co. 89 RESISTANCE TEMPERATURE DETECTORS Series 707 • Industrial Design with Cast Screw Cover Heads • “Factory Mutual” Approved Heads in Cast Iron and Aluminum • Various Male NPT Mounting Fittings are Available • Standard Resistance Value 100 Ohms at 0°C, Others Available Enter a selection for each item, please fax your inquiry to TCP. 707 - Example: IMMERSION LENGTH “L” Specify in inches CODE TERMINATION STYLE 0 AL CI P None Aluminum Head Cast Iron Head Poly Head Code CI - Cast Iron...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com Thermo-Couple Products Co. 1-800-727-5646 90 RESISTANCE TEMPERATURE DETECTORS Series 808 • Bare Leads Provided for Termination of Your Choice • Replacement RTD Element • Close Interchangeability • Standard Resistance Value 100 Ohms at 0°C, Others Available • Standard Resistance Tolerance of ± 0.1% at 0°C is Standard • Standard Temperature Coefficient .00385 Ù/Ù/°C Enter a selection for each item, please fax your inquiry to TCP. 808 - Example: 808 - A - 100 - F - 5 - 0 - 3 - 304 - 0 - - - - - - - IMMERSION LENGTH “L” Specify...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com 1-800-727-5646 91 Thermo-Couple Products Co. 91 RESISTANCE TEMPERATURE DETECTORS Series 909 • Superior Stability, Repeatability and Accuracy • Vibration and Shock Resistant • Supplied with a Lightweight Miniature Screw Coverhead • Standard Resistance Value 100 Ohms at 0°C, Others Available • Standard Resistance Tolerance of ± 0.1% at 0°C is Standard • Standard Temperature Coefficient .00385 Ù/Ù/°C Enter a selection for each item, please fax your inquiry to TCP. 909 - Example: 909 - A - 100 - F - 5 - 3 - 304 - 50 - 0 - - -...

www.tcproducts.com a division of Marsh Bellofram www.marshbellofram.com Thermo-Couple Products Co. 1-800-727-5646 92 REFINERY RTD ASSEMBLY Series 2101 • Complete RTD Assembly with Cast Head • PVC Coated Flex Armor Provides Moisture Resistance • Complete with 1/2" NPT Mounting Adapter • Design Fits Most Thermowells • Standard Resistance Value 100 Ohms at 0°C, Others Available 2101 - A - 100 - F - 18 - 36 - 3 - 304 - CI - 0 Enter a selection for each item, please fax your inquiry to TCP. 2101 - Example: - - - - - - - - ! Metric Ord e rs Welcome Place an mm in the appropriate selection box: 100...