HJMTSS

Supported Applications

The Omega HJMTSS series comprises High Temperature Thermocouple Probes with Lead Wire, designed for temperature measurement using transition junction style probes. These sensors feature high-temperature molded construction and are manufactured from Special Limits of Error (SLE) material.

• Temperature sensing in applications requiring subminiature or standard diameter sheath options
• Installations utilizing ANSI color code lead wires, with IEC color codes available upon request via omega.com

Operating Conditions & Performance

The series meets or exceeds Special Limits of Error (SLE) and EN 60584-2, Tolerance Class 1 accuracy standards. The environmentally friendly Cadmium-Free Liquid Crystal Polymer Molded Transition Junction is rated to 260°C (500°F). Standard electrical connections include 914 mm (36") Teflon®-Coated Lead Wires.

• Sheath diameters: 0.25 mm (0.010") to 3.18 mm (0.125")
• Stem and overall lengths: 150 mm (6") or 300 mm (12"); other lengths available upon consultation with the Sales Department

Junction Type Selection

Selectors must specify the junction type during ordering:

• 'E' for Exposed Junction
• 'G' for Grounded Junction
• 'U' for Ungrounded Junction

Configuration Options

The HJMTSS series supports a broad envelope of thermocouple alloys, sheath materials, and dimensional configurations. While standard variants utilize 304 Stainless Steel (SS) sheaths, the series is configurable for Inconel or XL options to meet specific temperature and stability requirements.

Thermocouple Alloys

The following thermocouple types are available within the series:

• Type J: Iron-Constantan (Iron-Constantan 304 SS Sheath)
• Type K: CHROMEGA® ALOMEGA® (CHROMEGA® ALOMEGA® 304 SS Sheath)
• Type E: CHROMEGA® Constantan (CHROMEGA® Constantan 304 SS Sheath)
• Type T: Copper-Constantan (Copper-Constantan 304 SS Sheath)

Sheath and Housing Options

Standard sheaths are constructed from 304SS. Alternative materials include:

• Inconel Sheath: Change 'SS' to 'IN' in the model number (e.g., HKMTIN-125G-6)
• XL Option: For highest temperature and stability rating, change 'SS' or 'IN' to 'XL'

Transition Junction Construction

The transition junction construction varies by probe diameter:

• Probes with 1.02 mm (0.040") diameter and larger are supplied with molded transition joints.
• Smaller-size probes are supplied with stainless steel transition joints.
• All Type-N probes are supplied with stainless steel transition joints.

Model Number Configuration

The model number follows the format: HJMTSS---. An example configuration is HKMTSS-125G-6, representing a subminiature transition joint probe, Type K, 1.5 mm (0.125") OD stainless steel sheath, 150 mm (6") length, grounded junction.

Key Product Differences

Variants within the HJMTSS series are distinguished by thermocouple type, sheath material, diameter, and total probe length. The model number prefix indicates the specific alloy: 'H' denotes High Temperature probes with lead wire; subsequent letters indicate Type J (Iron-Constantan), K (CHROMEGA® ALOMEGA®), E (CHROMEGA® Constantan), or T (Copper-Constantan). Sheath material is indicated by suffixes such as 'SS' for 304 Stainless Steel, 'IN' for Inconel, and 'XL' for the highest temperature rating. Junction types are encoded in the model number using 'E', 'G', or 'U'. Length codes correspond to specific stem dimensions, with standard offerings at 150 mm (6") and 300 mm (12").