38999 Series 1 Type Thermocouples

Thermocouple Contact & Tooling Charts

d38999-series-III-contacts

Milnec Interconnect Systems manufacturers a full offering of MIL-DTL-38999 Series I type high reliability thermocouple crimp contacts in the most popular thermocouple materials. By ordering thermocouple contacts separately, engineers can quickly make custom connector solutions to run power, signal, and thermocouples in one cable! In charts below you can find all the information required to order replacement thermocouple contacts for all existing MIL-DTL-38999 Series I connectors. Next to each contact is appropriate tooling information for required crimper, positioner, insertion and extraction tweezers.

Put simply, a thermocouple is a pair of wires of dissimilar metal that is connected at both ends. When the two wire junctions are exposed to different temperatures, an electrical potential is created between them that is almost directly proportional to the temperature difference. A voltage measuring instrument added to the circuit can then read the temperature. Thermocouples are made from a variety of specific alloys and are best suited for different applications depending on the intended temperature range, sensitivity, resistance to corrosion, magnetism, and cost. Because crimp connectors have removable contacts, the standard contacts can be substituted easily with thermocouples.

Thermocouple Types

Certain combinations of alloys have become popular as industry standards for thermocouples. Milnec’s standard thermocouple types are listed below with the positive electrode first, followed by the negative electrode.

Type K (chromel/alumel)

The most common general purpose thermocouple with a sensitivity of approximately 41 µV/°C, chromel positive relative to alumel.

Type E (chromel/constantan)

This type has a high output (68 µV/°C), which makes it well suited to cryogenic use. In addition, it is non-magnetic.

Type J (iron/constantan)

This combination has a more restricted range than Type K (0° to +750°C), but has a higher sensitivity (55 µV/°C).

Thermocouple Types Chart

Thermocouple Type Temperature Range (Continuous)* Temperature Range (Short Term)* Thermocouple Materials Contact Size Termination
K +32° to +2,012°F
(0° to +1,100°C)
-292° to +2,372°F
(-180° to +1,300°C)
Chromel & Alumel #16, #20, #22D Crimp
E +32° to +1,472°F
(0° to +800°C)
-40° to +1,652°F
(-40° to +900°C)
Chromel & Constantan #16, #20, #22D Crimp
J +32° to +1,382°F
(0° to +750°C)
-292° to +1,472°F
(-180° to +800°C)
Iron & Constantan #16, #20, #22D Crimp

* Please note above thermocouple temperature ranges are for reference only. Standard connector insert materials can only withstand 392°F (200°C) of continuous operation.

Additional Resources

38999 Series I Contact Data Sheets

Thermocouple Contacts

Contact Size Contact Style Part Number Wire Size (AWG) Wire Range (Dia) Jacket Strip Length Crimping Tool Positioner Insertion Tool Extraction Tool
#22D Alumel Pin DLPA22 22, 24, 26, 28 .012–.025 (.32–.64) .157 (4.00) TK201 TP209 TN801 TX802
Socket DLSA22 TP207
#22D Chromel Pin DLPR22 TP209
Socket DLSR22 TP207
#22D Constantan Pin DLPK22 TP209
Socket DLSK22 TP207
#22D Iron Pin DLPE22 TP209
Socket DLSE22 TP207
#20 Alumel Pin DLPA20 20, 22, 24 .020–.032 (.51–.81) .197 (5.00) TK101 TP104
(Turret)
TN805 TX806
Socket DLSA20
#20 Chromel Pin DLPR20
Socket DLSR20
#20 Constantan Pin DLPK20
Socket DLSK20
#20 Iron Pin DLPE20
Socket DLSE20
#16 Alumel Pin DLPA16 16, 18, 20 .032–.050 (.81–1.29) .236 (6.00) TK101 TN807 TX808
Socket DLSA16
#16 Chromel Pin DLPR16
Socket DLSR16
#16 Constantan Pin DLPK16
Socket DLSK16
#16 Iron Pin DLPE16
Socket DLSE16

Dimensions are in inches (mm) unless otherwise noted.