SPPL

Supported Applications

The Omega SPPL series consists of Platinum-Rhodium fine-diameter bare thermocouple wire designed for high-temperature applications. The product overview identifies the primary use case as continuous service in oxidizing or inert atmospheres, with specific temperature limits defined by type: up to 1398°C (2550°F) for Types R and S, and up to 1704°C (3100°F) for Type B. The series offers high resistance to oxidation and corrosion at these elevated temperatures.

Media compatibility is restricted by atmospheric conditions:

• Oxidizing or inert atmospheres
• Vacuum (short periods)
• Not suitable for reducing atmospheres or atmospheres containing metallic or non-metallic vapors unless protected by non-metallic protection tubes

The series is available as uninsulated noble metal thermocouple wire and insulated duplex extension grade wire. Matched pairs are offered to provide the highest accuracy.

Operating Conditions & Performance

Performance limits vary by thermocouple type, with continuous operating temperatures reaching up to 1398°C (2550°F) for Types R and S, or short-term use at 1482°C (2700°F). Type B wire supports operation up to 1704°C (3100°F) continuously. The measurement range is documented as 1398 to 1482°C (2550 to 2700°F) for Types R and S, and up to 1704°C (3100°F) for Type B.

Wire diameters span from 0.025 mm (0.001 inch) to 0.812 mm (0.032 inch). The series is classified as High Accuracy, with wire supplied in matched pairs that meet or exceed standard limits of error; special-limits-of-error wire is available on request and must be ordered as matched pairs.

Installation constraints include a warning not to insert the wire directly into metallic protection tubes. Metric dimensions are noted as approximate.

Configuration Options

The SPPL series supports multiple material compositions, output configurations (single or matched pair), and diameters:

• Materials: Platinum (RN, SN); Platinum 10% Rhodium (SP); Platinum 13% Rhodium (RP); Platinum 6% Rhodium (BN); Platinum 30% Rhodium (BP).
• Diameters: Available in nominal sizes from 0.03 mm (0.001 inch) to 0.81 mm (0.032 inch), with specific model numbers corresponding to each size.
• Configuration: Offered as single uninsulated wire or matched pairs for Types R, S, and B.

Model numbering follows the pattern SPPL-<WIRE_DIAMETER> for Platinum (RN, SN), SP13RH-<WIRE_DIAMETER> for Platinum 13% Rhodium (RP), SP10RH-<WIRE_DIAMETER> for Platinum 10% Rhodium (SP), SP6RH-<WIRE_DIAMETER> for Platinum 6% Rhodium (BN), and SP30RH-<WIRE_DIAMETER> for Platinum 30% Rhodium (BP). Matched pairs use the format SP13R-<WIRE_DIAMETER>, SP10R-<WIRE_DIAMETER>, and SP30R-<WIRE_DIAMETER>.

Key Product Differences

Variants within the series are distinguished by thermocouple type, material composition, and whether they are supplied as single wire or matched pairs.

• Type R: Composed of Platinum vs. Platinum-13% Rhodium; available in diameters from 0.03 mm (0.001 inch) to 0.81 mm (0.032 inch).
• Type S: Composed of Platinum vs. Platinum-10% Rhodium; available in the same diameter range as Type R.
• Type B: Composed of Platinum-6% Rhodium vs. Platinum-30% Rhodium; available in diameters from 0.20 mm (0.008 inch) to 0.81 mm (0.032 inch).

The series also includes insulated duplex extension grade wire options for Types R, S, and B using Cu-Alloy or Cu-Cu materials with specific AWG ratings.