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Frequently Bought Together

1) Thermowells & Protection Tubes

2) Transmitters

3) Wire

Direct Mount Thermocouples & RTDs

Direct Mount Thermocouples and RTDs are commonly assembled with thermowells (ex: Series 5, 5T, 5L, 5F, and 5C ) and protection tubes (ex: Series 5P, 5D 5SL, 5R, 5A, 5V, 5G, 5B, and 5E) . Direct Mount Thermocouples and RTDs matched to thermowells can be configured from this page. Thermocouples and RTDs matched to ceramic protection tubes can be configured here or matched to metal protection tubes here.

Attaching devices are an important part of direct mount sensor construction. When assembled with a metal protection tube or thermowell, spring loading attaching devices are often preferred as they ensure that the tip of the sensor always remains in metal-to-metal contact with the inside wall of the thermowell or protection tube.

Spring loading provides two additional benefits to a direct mount sensor: (1) faster response time, and (2) precise sensor location within the process. JMS recommends that sensors be spring loaded inside a purpose built attaching device rather than loaded against the terminal block or transmitter as terminal blocks can break or warp and transmitters can be adversely impacted by pressure from the spring.

When assembling a direct mount sensor with a ceramic protection tube (ex: Series 5D and 5G) a compression fitting or welded fitting is preferred. Pressure on the tip of a ceramic protection tube from spring loading is not desirable and can lead to shorter lifespans for ceramic tubes.

Nipple unions extensions [1-3] are often desirable for direct mount sensors as they enable orienting the enclosure to match up to conduit runs. Unions also enable sensor removal without disconnecting the element from flexible conduit. Finally, where thermowell lagging is buried in insulation, a length of pipe nipple can serve to extend the union outside of the insulation.

Enclosures come in all varieties of materials and area classifications. Click here for more information.

Indicating transmitters can be assembled with direct mount sensors using windowed housings. Where a local indication is not needed but a 4-20mA signal is desirable, hockey puck transmitters can be assembled inside nearly any JMS enclosure. JMS offers its own line of transmitters as well as transmitters offered by other manufacturers including Emerson, ABB, E+H, and many more. New!! Now available with Ex certified ratings!!

Cut Sheets
Technical Information
White Papers
Resources

Cut Sheets
Technical Information
White Papers
Resources

Cut Sheets

Thermocouple Type Material & Color Code
Thermocouple Sheath Material Temperature Limits
Thermocouple Temperature Limits By Sheath Diameter
Thermocouple Limits of Error and Published Range For Bare Wire
RTD Standards
RTD Tolerances
Wire Insulation Material
Non-Insulated Single Conductor Thermocouple Type

Thermocouple Type	Material	Magnetic	ASTM Color Coding	IEC Color Coding
J	Iron Constantan	Yes No	White Red	White Black
T	Copper Constantan	No No	Blue Red	White Brown
K	Chromel Alumel	No No	Yellow Red	White Green
E	Chromel/Constantan	No No	Purple Red	White Violet
P	Platinel	N/A	N/A	N/A
S	Platinum 10% Rhodium Pure Platinum	No No	Black Red	White Orange
R	Platinum 13% Rhodium Pure Platinum	No No	Black Red	white Orange
B	Platinum 30% Rhodium Platinum 6% Rhodium	No No	Grey Red	White Grey
N	Nicrosil/Nisil	No Slightly	Orange Red	White Pink
C	Tungsten 5% Rhenium/ Tungsten 26% Rhenium	No No	White Red	N/A

Material Symbol	Sheath Material	Melting Point(°F)	Max Temp; In Air(°F)	Atmosphere^*
H	304 SS	2550	1650	ORNV
J	310 SS	2550	2100	ORNV
L	316L SS	2550	1650	ORNV
O	446 SS	2700	2100	ORNV
M	Inconel 600	2500	2100	ONV
P	Inconel 702	2620	1500	ONV
Q	Platinum	3216	3000	ON
R	Molybdenum	4750	1000	VNR
T	Titanium	3300	600	V
V	STABALOY	2552	2220	ORNV

^*KEY

O=Oxidizing, R=Reducing, N=Neutral, V=Vacuum

Suggested Upper Limit for Outside Diameter (Single Element) °C (°F)
Sheath		Thermocouple Type
In	mm	T	J	E	K	N
1/25"	1.0	260° (500°)	260° (500°)	300° (570°)	700° (1290°)	2700° (1290°)
1/16"	1.6	260° (500°)	440° (825°)	510° (950°)	920° (1690°)	920° (1690°)
1/8"	3.2	315° (600°)	520° (970°)	650° (1200°)	1070° (1950°)	1070° (1950°)
3/16"	4.8	370° (700°)	620° (1150°)	730° (1350°)	1150° (2100°)	1150° (2100°)
1/4"	6.3	370° (700°)	720° (1330°)	820° (1510°)	1150° (2100°)	1150° (2100°)
3/8"	9.5	370° (700°)	720° (1330°)	820° (1510°)	1150° (2100°)	1150° (2100°)

ANSI Thermocouple Type	Temp Range (°C)	Temp Range (°F)	Standard Limits of Error (°C)^*	Special Limits of Error (°C)
J	0 to 760	32 to 1400	The greater of ±2.2 or ±0.75%	The greater of ±2.2 or ±0.75%
T	0 to 370	32 to 700	The greater of ±1 or ±0.75%	The greater of ±0.5 or ±0.4%
K	0 to 1260	32 to 2300	The greater of ±2.2 or ±0.75%	The greater of ±1.1 or ±0.4%
E	0 to 870	32 to 1600	The greater of ±1.7 or ±0.5%	The greater of ±1 or ±0.4%
S	0 to 1480	32 to 2700	The greater of ±1.5 or ±0.25%	The greater of ±0.6 or ±0.1%
R	0 to 1480	32 to 2700	The greater of ±1.5 or ±0.25%	The greater of ±0.6 or ±0.1%
N	0 to 1246	32 to 2300	The greater of ±2.2 or ±0.75%	The greater of ±1.1 or ±0.4%
B	870 to 1700	1600 to 3100	±0.5%	±0.25%
T^A	-200 to 0	-328 to 32	The greater of ±1 or ±1.5%	^B
E^A	-200 to 0	-328 to 32	The greater of ±1.7 or ±1%	^B
K^A	-200 to 0	-328 to 32	The greater of ±2.2 or ±2%	^B

^A: Thermocouple and thermocouple materials are normally supplied to meet the tolerances specified in the table of temperatures above 0°C. The same materials, however, may not fall within the tolerances given for temperatures below 0°C in the normal section in the table. If materials are required to meet the tolerances stated for temperatures below 0°C the purchase order must specifically state that requirement. Selection of materials will usually be required.

^B: Special tolerances for temperatures below 0°C are difficult to justify due to limited available information.

*: Standard and special limits of error in °F are 1.8 times larger thant the °C tolerance at the equivalent °C temperature.

Organization	Standard	Alpha	Nominal Resistance(ohms) At 0°C
International Electrotechnical Commission (Supersedes BS & DIN)	IEC 60751: 2022	0.00385	100
ASTM International	ASTM E1137/E1137M-08 (2020)	0.00385	100
American Scientific Apparatus Makers Association (SAMA)	RC21-4-1966	0.003923	98.129
British Standards Association	b.S. 1904-1964	0.00385	100
Normenstelle Elektrotechnik	DIN 43760	0.00385	100
US Department of Defense	MIL-T-24388	0.00392	100

Tolerance Classes for Wound Resistors

Tolerance Class	Tolerance Value (°C)	Temperature Range of Validity of Tolerances
W 0.1	±(0.1° + 0.0017[t])	-50° to 250°
W 0.15	±(0.15° + 0.002[t])	-100° to 450°
W 0.3	±(0.3° + 0.005[t])	-196° to 661°
W 0.6	±(0.6° + 0.01[t])	-196° to 661°

Tolerance Classes for Film Resistors

Tolerance Class	Tolerance Value (°C)	Temperature Range of Validity of Tolerances
F 0.1	±(0.1° + 0.0017[t])	-50° to 250°
F 0.15	±(0.15° + 0.002[t])	-50° to 450°
F 0.3	±(0.3° + 0.005[t])	-50° to 661°
F 0.6	±(0.6° + 0.01[t])	-50° to 661°

Tolerance Classes for Thermometers (Finished Probes)

Tolerance Class	Tolerance Value (°C)	Temperature Range of Validity of Tolerances
AA	±(0.1° + 0.0017[t])	-50° to 250°
A	±(0.13° + 0.0017[t])	-100° to 450°
B	±(0.25° + 0.0042[t])	-196° to 600°
C	±(0.6° + 0.01[t])	-196° to 600°

WIRE INSULATION MATERIAL

POLYVINYL CHLORIDE INSULATED WIRE

Polyvinyl Chloride-Polyvinyl Chloride - PP

Color-coded polyvinyl chloride is extruded on each individual conductor and on the outer jacket. It has dielectric and mechanical strength, plus flexibility. PVC is resistant to flame, moisture and abrasion. It is also inexpensive and easily pulled through a conduit. lt is offered in thermocouple extension grade. Temperature rating: Continuous: -20 to +221°F (-29 to 105°C)

Polyvinyl Chloride Rip-Cord Construction - PC

Polyvinyl chloride is extruded on both positive and negative conductors simultaneously to form a rip-cord construction. Offered in thermocouple grade 24 gauge solid conductors. Temperature rating: Continuous: -20 to +221°F (-29 to 105°C)

Polyvinyl Chloride with Twisted Conductors, Aluminum Mylar* Shield, and Drain Wire - PA

Polyvinyl chloride insulates the positive and negative conductors. The conductors are then twisted and helically wrapped with an aluminum backed Mylar* tape. A bare copper drain wire runs through the construction in contact with the aluminum tape furnishing a low resistance path to ground. The twisted shield provides electrostatic interference rejection. The outer jacket is of polyvinyl chloride which has excellent mechanical strength. Wire is resistant to flame, moisture, and abrasion. Offered in extension grade. Thermocouple grade available upon request. Temperature rating: Continuous: Up to 176°F and 80°C

*Trade name of DuPont.

KAPTON INSULATED WIRE

Kapton - KK

Kapton polyimide film is applied to both the positive and negative conductor or just to the positive conductor. Kapton is highly resistive to abrasion, radiation and is non-flammable. Excellent for use in extremely harsh environments. No ISA/ ASTM color code. Kapton has no known organic solvents. Kapton is an excellent choice for cryogenic environments because its insulating characteristics remain intact at lower temperatures. Offered in thermocouple grade. Temperature rating: Continuous: Up to 550°F (285°C). Intermittent: Up to 750°F (400°C).

NYLON INSULATED WIRE

Nylon-Nylon - NN

Color-coded nylon is extruded on both positive and negative conductors with a nylon outer jacket. This insulation has excellent abrasion resistance, excellent chemical resistance, and poor moisture resistance. Offered in thermocouple grade. Temperature rating: Continuous: Up to 350°F and 177°C.

TEFLON INSULATED WIRE

Teflon (extruded) Teflon (extruded) - TT

Color-coded Teflon (FEP)* is extruded on the positive and negative conductors and outer jacket. This insulation is unaffected by most corrosive substances, outdoor weather, or lubricants. It is flame resistant and heat aging will not cause embrittlement or cracking. Good for cryogenic applications. Offered in thermocouple grade. Temperature rating: Continuous: Up to 400°F (200°C).

Teflon (Fused TFE Tape) Teflon (Fused TFE Tape) - TF

TFE tape is spirally applied to the conductor and heated. This process fuses the tape into a homogeneous layer of TFE. Fused teflon wire offers good abrasion resistance and excellent resistance to both moisture and chemicals. Offered in thermocouple grade. Temperature rating: Continuous: Up to 500°F (260°C).

*DuPont Trademark

FIBROUS INSULATED WIRE

Fiberglass Braid - GG

Glass braid on individual conductors with glass braid outer jacket. Designed for continuous use in high temperature applications. Poor abrasion and moisture resistance. Offered in thermocouple grade. Temperature rating: Continuous: Up to 900°F (482°C). Intermittent: Up to 1000°F (529°C).

Hightemp Fiberglass Braid - HG

A high temperature fiberglass braid is applied over each conductor and then impregnated with a binder. Although the binder improves resistance to abrasion and moisture, it is destroyed above 400°F (204°C). Offered in thermocouple grade. Temperature rating: Continuous: Up to 1300°F (705°C). Intermittent: Up to 1600°F (871°C). We recommend SS overbraid with this wire (Ordering Code HS).

Fiberglass and Hightemp Fiberglass Braid with Stainless Steel Overbraid - GS and HS

A stainless steel overbraid is applied to fiberglass (Ordering Code GS) or high temperature fiberglass (Ordering Code HS) wire insulation to increase the wire’s resistance to abrasion, mechanical and physical damage. It may be applied to 14 through 30 gauge conductors. Other overbraid materials such as Inconel* are also available by special order codes.

*Special Metals Corporation Trademark

Refrasil - RR

Vitreous silica is applied on both positive and negative conductors with a vitreous silica outer jacket. Refrasil is typically not color coded. Used in high temperature applications, including furnace, load thermocouple and traveling thermocouple applications. Moisture and abrasion resistance only fair. Offered in thermocouple grade. Available with SAE AMS 2750 compliant calibration data. Temperature rating: Continuous: Up to 1600°F (871°C). Intermittent: Up to 1800°F (982°C). We recommend stainless steel or other overbraid with this wire.

Nextel - NE

A high temperature ceramic fiber is applied over each conductor and then overall. Nextel is not colored coded. Although nextel is not recommended for use with platinum thermocouples, it can be used as an excellent option for other high temperature applications. Its use is limited by the temperature rating of the thermocouple wire it insulates. It is frequently used in furnace and traveling thermocouple applications. Available with SAE AMS 2750 compliant calibration data. Temperature rating: Continuous: Up to 2200°F (1200°C). We recommend SS overbraid with this wire.

Thermocouple Type	Material	Magnetic	ASTM Color Coding	IEC Color Coding
J	Iron Constantan	Yes No	White Red	White Black
T	Copper Constantan	No No	Blue Red	White Brown
K	Chromel Alumel	No No	Yellow Red	White Green
E	Chromel/Constantan	No No	Purple Red	White Violet
P	Platinel	N/A	N/A	N/A
S	Platinum 10% Rhodium Pure Platinum	No No	Black Red	White Orange
R	Platinum 13% Rhodium Pure Platinum	No No	Black Red	white Orange
B	Platinum 30% Rhodium Platinum 6% Rhodium	No No	Grey Red	White Grey
N	Nicrosil/Nisil	No Slightly	Orange Red	White Pink
C	Tungsten 5% Rhenium/ Tungsten 26% Rhenium	No No	White Red	N/A

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