Endress+Hauser TM411 Specifications

TI01038T/09/EN/06.18
71419901
2018-12-12

Products

Solutions Services

Technical Information

iTHERM TM411

Trend-setting, modular resistance thermometer
for hygienic and aseptic applications

Easy-to-use metric version with outstanding
sensor
technology

Applications

• Specially designed for use in hygienic and aseptic applications in the Food &
Beverages and Life Sciences industries

• Measuring range: –200 to +600 °C (–328 to +1 112 °F)

• Pressure range up to 50 bar (725 psi)

• Protection class: up to IP69K

Head transmitter

All Endress+Hauser transmitters are available with enhanced accuracy and reliability
compared to directly wired sensors. Easy customizing by choosing one of the
following outputs and communication protocols:

• Analog output 4 to 20 mA, HART

• PROFIBUS® PA, FOUNDATION Fieldbus™

Your benefits

• User-friendly and reliable from product selection to maintenance

• iTHERM inserts: globally unique, automated production. Full traceability and
consistently high product quality for reliable measured values

• iTHERM QuickSens: fastest response times (t

• iTHERM StrongSens: unsurpassed vibration resistance (> 60g) for ultimate plant
safety

• iTHERM QuickNeck – cost and time savings thanks to simple, tool-free
recalibration

• iTHERM TA30R: 316L terminal head for easier handling and lower installation
and maintenance costs, and with highest IP69K rating

• International certification: explosion protection e.g. ATEX/IECEx and in compliance
with hygiene standards according to 3-A®, EHEDG, ASME BPE, FDA, TSE
Certificate of Suitability

®

: 1.5 s) for optimum process control

90s

Table of contents

iTHERM TM411

Function and system design ................... 3

iTHERM Hygiene line ........................... 3

Measuring principle ............................ 3

Measuring system ............................. 4

Modular design ............................... 5

Input ..................................... 6

Measured variable ............................. 6

Measuring range .............................. 6

Output ................................... 6

Output signal ................................ 6

Family of temperature transmitters ................. 6

Wiring ................................... 7

Wiring diagrams for RTD ........................ 7

Cable entries ................................ 8

Device plugs ................................. 8

Overvoltage protection ......................... 10

Performance characteristics .................. 10

Reference conditions .......................... 10

Accuracy .................................. 11

Influence of ambient temperature ................. 11

Self heating ................................ 11

Response time .............................. 12

Calibration ................................. 13

Insulation resistance .......................... 14

Thermowell ................................ 36

Certificates and approvals ................... 46

CE mark ................................... 46

Hygiene standard ............................ 46

Ex approval ................................ 46

Other standards and guidelines ................... 46

CRN approval ............................... 46

Areas in contact with medium .................... 46

Surface roughness ............................ 46

Material resistance ........................... 46

Material certification .......................... 46

Calibration ................................. 46

Thermowell testing and load capacity calculation ....... 47

Ordering information ....................... 47

Accessories ............................... 47

Device-specific accessories ...................... 48

Communication-specific accessories ................ 49

Service-specific accessories ...................... 50

System components ........................... 51

Documentation ............................ 51

Installation ............................... 15

Orientation ................................ 15

Installation instructions ........................ 15

Environment .............................. 17

Ambient temperature range ..................... 17

Storage temperature .......................... 17

Humidity .................................. 17

Climate class ............................... 17

Degree of protection .......................... 17

Shock and vibration resistance .................... 17

Electromagnetic compatibility (EMC) ............... 17

Process .................................. 17

Process temperature range ...................... 17

Thermal shock .............................. 17

Process pressure range ......................... 17

Medium - state of aggregation .................... 18

Mechanical construction .................... 18

Design, dimensions ........................... 18

Inserts .................................... 30

Weight ................................... 30

Material .................................. 30

Surface roughness ............................ 31

Terminal heads .............................. 31

Extension neck .............................. 35

2 Endress+Hauser

iTHERM TM411

mm

inch

mm

inch

Function and system design

iTHERM Hygiene line

This thermometer is part of the product line of modular thermometers for hygienic and aseptic
applications.

Differentiating factors when selecting a suitable thermometer

TM4x1 TM4x2

Metric version Imperial version

↓ ↓

TM41x characterizes the device that uses cutting-edge technology, with features such as a replaceable insert,

quick-fastening extension neck (iTHERM QuickNeck), vibration-resistant and fast-response sensor technology

(iTHERM StrongSens and QuickSens) and approval for use in hazardous areas

TM411

TM412

↓ ↓

TM40x characterizes the device that uses basic technology, with features such as a fixed, non-replaceable

insert, application in non-hazardous areas, standard extension neck, low-cost unit

TM401

Measuring principle Resistance thermometer (RTD)

These resistance thermometers use a Pt100 temperature sensor according to IEC 60751. The
temperature sensor is a temperature-sensitive platinum resistor with a resistance of 100 Ω at
0 °C (32 °F) and a temperature coefficient α = 0.003851 °C-1.

A0018239

A0018692

A0018691

TM402

A0018693

Endress+Hauser 3

iTHERM TM411

Commubox

FieldCare

1

PLC

°C

2

3

There are generally two different kinds of platinum resistance thermometers:

• Wire wound (WW): Here, a double coil of fine, high-purity platinum wire is located in a ceramic
support. This is then sealed top and bottom with a ceramic protective layer. Such resistance
thermometers not only facilitate very reproducible measurements but also offer good long-term
stability of the resistance/temperature characteristic within temperature ranges up to
600 °C (1 112 °F). This type of sensor is relatively large in size and it is comparatively sensitive to
vibrations.

• Thin film platinum resistance thermometers (TF): A very thin, ultrapure platinum layer,
approx. 1 μm thick, is vaporized in a vacuum on a ceramic substrate and then structured
photolithographically. The platinum conductor paths formed in this way create the measuring
resistance. Additional covering and passivation layers are applied and reliably protect the thin
platinum layer from contamination and oxidation, even at high temperatures.

The primary advantages of thin film temperature sensors over wire wound versions are their smaller
sizes and better vibration resistance. A relatively low principle-based deviation of the resistance/
temperature characteristic from the standard characteristic of IEC 60751 can frequently be observed
among TF sensors at high temperatures. As a result, the tight limit values of tolerance category A as
per IEC 60751 can only be observed with TF sensors at temperatures up to approx. 300 °C (572 °F).
For this reason, thin-film sensors are generally only used for temperature measurements in ranges
below 400 °C (752 °F).

Measuring system

Endress+Hauser offers a complete portfolio of optimized components for the temperature measuring
point – everything you need for the seamless integration of the measuring point into the overall
facility. This includes:

• Power supply unit/barrier

• Display units

• Overvoltage protection

For more information, see the brochure 'System Components - Solutions for a Complete
Measuring Point' (FA00016K/EN)

 1 Example of application, measuring point layout with additional Endress+Hauser components

1

Installed iTHERM resistance thermometer with integrated HART® head transmitter

2 RIA16 field display unit - The display unit records the analog measuring signal from the head transmitter and

shows this on the display. The LC display shows the current measured value in digital form and as a bar graph
indicating a limit value violation. The display unit is looped into the 4 to 20 mA circuit and gets the required
energy from there. More information on this can be found in the Technical Information, see "Documentation",
→  51.

3 Active barrier RN221N - The RN221N (24 V DC, 30 mA) active barrier has a galvanically isolated output for

supplying voltage to loop-powered transmitters. The universal power supply works with an input supply
voltage of 20 to 250 V DC/AC, 50/60 Hz, which means that it can be used in all international power grids.
More information on this can be found in the Technical Information, see "Documentation", →  51.

A0017693

4 Endress+Hauser

iTHERM TM411

U

1

2

3

4

5

6

7

7a 7b

Modular design

Design Options

A0017758

1: Terminal
head →  31

2: Wiring,
electrical
connection,
output signal
→  6

3: Connector or
cable gland
→  34

4: Extension
neck →  35

5: Process
connection
→  36

6: Protection
tube →  36

7: Insert
→  30 with:
7a: iTHERM
QuickSens
7b: iTHERM
StrongSens

• 316L, low head, optionally with display window

• Aluminum, high or low head, with or without display window

• Polypropylene, low head

• Polyamide, high head, without display window

Your benefits:



• Optimum terminal access thanks to low housing edge of bottom
section:
– Easier to use
– Lower installation and maintenance costs

• Optional display: local process display unit for added reliability

• IP69K protection: optimum protection even with high-pressure
cleaning

• Ceramic terminal block

• Flying leads

• Head transmitter (4 to 20 mA, HART®, PROFIBUS® PA,
FOUNDATION™ Fieldbus), single-channel or two-channel

• Attachable display (optional)

• PROFIBUS® PA / FOUNDATION™ Fieldbus connector, 4-pin

• 8-pin connector

• Polyamide or brass cable glands

Welded-in-place or removable either with the quick fastener (iTHERM
QuickNeck) or thread adapter nut G3/8"

Your benefits:



• iTHERM QuickNeck: tool-free removal of the insert:
– Saves time/costs on frequently calibrated measuring points
– Wiring mistakes avoided

• IP69K protection: safety under extreme process conditions

More than 50 different versions.

• Versions with and without protection tube (insert in direct contact
with process).

• Various diameters

• Various tip shapes (straight or reduced)

Sensor models: wire wound (WW) or thin-film sensor (TF).

Your benefits:



• iTHERM QuickSens - insert with the world's fastest response
time:
– Insert: 3 mm (¹⁄₈ in) or 6 mm (¹⁄₄ in)
– Fast, highly accurate measurements, delivering maximum

process safety and control
– Quality and cost optimization
– Minimization of necessary immersion length: better product

protection thanks to improved process flow

• iTHERM StrongSens - insert with unbeatable durability:
– Vibration resistance > 60g: lower life cycle costs thanks to

longer operating life and high plant availability

– Automated, traceable production: top quality and maximum

process safety

– High long-term stability: reliable measured values and high

level of system safety

Endress+Hauser 5

Input

iTHERM TM411

Measured variable

Measuring range

Output signal

Temperature (temperature-linear transmission behavior)

Depends on the type of sensor used

Sensor type Measuring range

Pt100 thin-film –50 to +400 °C (–58 to +752 °F)

Pt100 thin-film, iTHERM
StrongSens, vibration­resistant > 60g

Pt100 thin-film, iTHERM
QuickSens, fast-response

Pt100 wire wound, extended
measuring range

–50 to +500 °C (–58 to +932 °F)

–50 to +200 °C (–58 to +392 °F)

–200 to +600 °C (–328 to +1 112 °F)

Output

Generally, the measured value can be transmitted in one of two ways:

• Directly-wired sensors - sensor measured values forwarded without a transmitter.

• Via all common protocols by selecting an appropriate Endress+Hauser iTEMP temperature
transmitter. All the transmitters listed below are mounted directly in the terminal head and wired
with the sensory mechanism.

Family of temperature transmitters

Thermometers fitted with iTEMP transmitters are an installation-ready complete solution to
improve temperature measurement by significantly increasing accuracy and reliability, when
compared to direct wired sensors, as well as reducing both wiring and maintenance costs.

PC programmable head transmitters

They offer a high degree of flexibility, thereby supporting universal application with low inventory
storage. The iTEMP transmitters can be configured quickly and easily at a PC. Endress+Hauser offers
free configuration software which can be downloaded from the Endress+Hauser Website. More
information can be found in the Technical Information.

HART® programmable head transmitters

The transmitter is a 2-wire device with one or two measuring inputs and one analog output. The
device not only transfers converted signals from resistance thermometers and thermocouples, it also
transfers resistance and voltage signals using HART® communication. It can be installed as an
intrinsically safe apparatus in Zone 1 hazardous areas and is used for instrumentation in the
terminal head (flat face) as per DIN EN 50446. Swift and easy operation, visualization and
maintenance by PC using operating software, Simatic PDM or AMS. For more information, see the
Technical Information.

PROFIBUS® PA head transmitters

Universally programmable head transmitter with PROFIBUS® PA communication. Conversion of
various input signals into digital output signals. High accuracy over the complete ambient
temperature range. Swift and easy operation, visualization and maintenance using a PC directly from
the control panel, e. g. using operating software, Simatic PDM or AMS. For more information, see
the Technical Information.

FOUNDATION Fieldbus™ head transmitters

Universally programmable head transmitter with FOUNDATION Fieldbus™ communication.
Conversion of various input signals into digital output signals. High accuracy over the complete
ambient temperature range. Swift and easy operation, visualization and maintenance using a PC
directly from the control panel, e.g. using operating software such as ControlCare from Endress
+Hauser or NI Configurator from National Instruments. For more information, see the Technical
Information.

6 Endress+Hauser

iTHERM TM411

3

5

6

RTD

3

4

5

6

RTD

1

2

3-wire

4-wire

Power supply
head transmitter and
analog output 4 to 20 mA,
or bus connection

(red) (red)
(red) (red)

(white) (white)

(white)

mA

-

+

+

1

-

2

7

6

5

4

3

1

2

7

6

5

4

3

Sensor input 2

Sensor input 1

RTD - and 3-wire: 4

RTD 3-wire:

Bus connection

and supply voltage

Display connection

red

white

red

red

red

white

white

(black)

(black)

(yellow)

Advantages of the iTEMP transmitters:

• Dual or single sensor input (optionally for certain transmitters)

• Unsurpassed reliability, accuracy and long-term stability in critical processes

• Mathematical functions

• Monitoring of the thermometer drift, sensor backup functionality, sensor diagnostic functions

• Sensor-transmitter matching for dual sensor input transmitter, based on Callendar/Van Dusen
coefficients

Wiring

• According to the 3-A® Standard electrical connecting cables must be smooth, corrosion­resistant and easy to clean.

• Grounding or shield connections are possible via special ground terminals on the terminal
head. →  31

Wiring diagrams for RTD

Type of sensor connection

Head mounted transmitter TMT18x (single input)

A0016433-EN

Head mounted transmitter TMT8x (dual input)

Endress+Hauser 7

A0008848-EN

Terminal block mounted

1 x Pt100

1 x Pt100

2 x Pt100

red

red

white

black

4 wires 3 wires 3 wires

white

red

red

black

yellow

red

white

red

white

iTHERM TM411

A0008591-EN

Cable entries

Device plugs

See 'Terminal heads' section →  31

Endress+Hauser offers a wide variety of connectors for the simple and fast integration of the
thermometer into a process control system. The following tables show the PIN assignments of the
various plug connector combinations.

Abbreviations

#1 Order: first transmitter/insert #2 Order: second

transmitter/insert

i Insulated. Wires marked 'i' are not connected and are

YE Yellow

insulated with heat shrink tubes.

GND Grounded. Wires marked 'GND' are connected to the

RD Red

internal grounding screw in the terminal head.

BN Brown WH White

GNYE Green-yellow PK Pink

BU Blue GN Green

GY Gray BK Black

Terminal head with one cable entry

Plug 1x PROFIBUS PA

Plug thread M12 7/8" 7/8" M12

PIN number 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 5 6 7 8

1x FOUNDATION™

Fieldbus (FF)

8-pin

Electrical connection (terminal head)

Flying leads Not connected (not insulated)

3-wire terminal

block (1x Pt100)

RD RD

4-wire terminal

block (1x Pt100)

RD

6-wire terminal

block (2x Pt100)

1x TMT 4 to 20

mA or HART

®

RD

(#1)

(#1)

1)

1)

+ i - i + i - i + i - i

2x TMT 4 to 20

mA or HART® in

the terminal

head with a high

cover

1x TMT

PROFIBUS® PA

8 Endress+Hauser

+

(#1)+(#2)-(#1)-(#2)+(#1)+(#2)-(#1)-(#2)+(#1)+(#2)-(#1)-(#2)

+

WH

RD RD

WH

WH

RD RD

WH WH WH WH WH WH WH WH

RD RD

RD

i

WH (#1)

GND

-

(#1)

1)

+

RD

(#1)

1)

i

WH (#1)

-

1)

2)

GND

2)

RD

(#1)

1)

RD

(#1)

1)

WH (#1)

1)

+

i

(#1)

1)

Cannot be combined Cannot be combined

WH

WH BK BK YE

­i

(#1)

+

(#2)

i

i

i

-

(#2)

i

iTHERM TM411

1 BN
2 GNYE
3 BU
4 GY

1

4 3

2

1 BN
2 GNYE
3 BU
4 GY

1

4

3

2

1 BU
2 BN
3 GY
4 GNYE

1

4

3

2

1 WH

2 BN

3 GN

4 YE

5 GY

6 PK

7 BU

8 RD

#1 #2

1 BN
2 GNYE
3 BU
4 GY

1

4 3

2

1 BN
2 GNYE
3 BU
4 GY

1

4

3

2

1 BU
2 BN
3 GY
4 GNYE

1

4

3

2

Plug 1x PROFIBUS PA

2x TMT

PROFIBUS® PA+(#1)

-

(#1)

1x TMT FF

Cannot be combined Cannot be combined

2x TMT FF

+ -

1x FOUNDATION™

Fieldbus (FF)

- +

-

(#1)+(#1)

PIN position and

color code

A0018929

A0018930

1) Second Pt100 is not connected

2) If a plastic housing TA30S or TA30P is used, insulated 'i' instead of grounded GND

Terminal head with two cable entries

Plug 2x PROFIBUS® PA 2x FOUNDATION™ Fieldbus (FF)

Plug thread

M12(#1) / M12(#2) 7/8"(#1) / 7/8"(#2) 7/8"(#1) / 7/8"(#2)

8-pin

GND i Cannot be combined

A0018931

A0018927

A0021706

PIN number 1 2 3 4 1 2 3 4 1 2 3 4

Electrical connection (terminal head)

Flying leads Not connected (not insulated)

3-wire terminal block (1x Pt100)

RD/i RD/i

WH/i

RD/i RD/i

WH/i

RD/i RD/i

WH/i

4-wire terminal block (1x Pt100) WH/i WH/i WH/i WH/i WH/i WH/i

6-wire terminal block (2x Pt100) RD/BK RD/BK WH/YE RD/BK RD/BK WH/YE RD/BK RD/BK WH/YE

1x TMT 4 to 20 mA or HART

2x TMT 4 to 20 mA or HART® in the

terminal head with a high cover

1x TMT PROFIBUS® PA +/i -/i

2x TMT PROFIBUS® PA

1x TMT FF

2x TMT FF

®

+/i

+(#1)/

+(#2)

i/i

-/i

-(#1)/

-(#2)

+/i

i/i

+(#1)/

+(#2)

-/i

-(#1)/

-(#2)

+/i

i/i

+(#1)/

i/i

+(#2)

-/i

-(#1)/

-(#2)

i/i

+/i -/i

+(#1)/

+(#2)

-(#1)/

-(#2)

GND/G

ND

+(#1)/

+(#2)

-(#1)/

-(#2)

GND/G

ND

Cannot be combined

-/i +/i

Cannot be combined Cannot be combined

-(#1)/

-(#2)

+(#1)/

+(#2)

i/i

PIN position and color code

A0018929

A0018930

i/i

GND/G

ND

A0018931

Endress+Hauser 9

iTHERM TM411

Connection combination: insert - transmitter

Insert

1x Pt100, flying

leads

2x Pt100, flying

leads

1x Pt100 with

terminal block

2x Pt100 with

terminal block

1) If 2 transmitters are selected in a terminal head, transmitter (#1) is installed directly on the insert. Transmitter (#2) is installed in the high cover.
A TAG cannot be ordered for the 2nd transmitter as standard. The bus address is set to the default value and, if necessary, must be changed
manually before commissioning.

2) Only in the terminal head with a high cover, only 1 transmitter possible. A ceramic terminal block is automatically fitted on the insert.

2)

2)

1x 1-channel 2x 1-channel

Pt100 (#1) : transmitter (#1)

Pt100 (#1) : transmitter (#1)

Pt100 (#1) : transmitter (#1)

Pt100 (#2) insulated

Pt100 (#1) : transmitter in

cover

Pt100 (#1) : transmitter in

cover

Pt100 (#2) not connected

Pt100 (#1) : transmitter (#1)
Pt100 (#2): transmitter (#2)

(Transmitter (#2) not

connected)

Cannot be combined

Transmitter connection

2)

Pt100 (#1) : transmitter (#1)

Pt100 (#1) : transmitter (#1)
Pt100 (#2) : transmitter (#1)

Pt100 (#1) : transmitter in

Pt100 (#1) : transmitter in

Pt100 (#2) : transmitter in

1)

1x 2-channel 2x 2-channel

Pt100 (#1) : transmitter (#1)

Transmitter (#2) not connected

Pt100 (#1) : transmitter (#1)
Pt100 (#2) : transmitter (#1)

(Transmitter (#2) not

connected)

cover

Cannot be combined

cover

cover

2)

Overvoltage protection

Reference conditions

To protect against overvoltage in the power supply and signal/communication cables for the
thermometer electronics, Endress+Hauser offers the HAW562 surge arrester for DIN rail mounting
and the HAW569 for field housing installation.

For more information see the Technical Information 'HAW562 Surge arrester' TI01012K and
'HAW569 Surge arrester' TI01013K.

Performance characteristics

These data are relevant for determining the accuracy of the temperature transmitters used. More
information on this can be found in the Technical Information of the iTEMP temperature
transmitters. →  51

10 Endress+Hauser

iTHERM TM411

A

AA

-200 -100 0 100 200 300 400 500 600°C

0.5

1.0

1.5

2.0

B

2.5

3.0

- 0.5

- 1.0

- 1.5

- 2.0

- 2.5

- 3.0

B

A

AA

Max. deviation (°C)

Max. deviation (°C)

Accuracy

RTD resistance thermometer as per IEC 60751

Class Max. tolerances (°C) Characteristics

Cl. AA, former 1/3

± (0.1 + 0.0017 · |t|

1)

)

Cl. B

Cl. A ± (0.15 + 0.002 · |t|)

Cl. B ± (0.3 + 0.005 · |t|)

Temperature ranges for compliance with the
tolerance classes

Wire wound
sensor (WW):

Cl. A Cl. AA

–

–50 to +250 °C

100 to +450 °C

Thin-film version

Cl. A Cl. AA

(TF):

• Standard

• iTHERM
QuickSens

• iTHERM

–30 to +300 °C
–30 to +200 °C

–30 to +300 °C

0 to +150 °C
0 to +150 °C

0 to +150 °C

StrongSens

1) |t| = absolute value °C

In order to obtain the maximum tolerances in °F, the results in °C must be multiplied by a factor
of 1.8.

Influence of ambient

Depends on the head transmitter used. For details, see Technical Information. →  51

temperature

Self heating

RTD elements are passive resistances that are measured using an external current. This
measurement current causes a self-heating effect in the RTD element itself which in turn creates an
additional measurement error. In addition to the measurement current, the size of the measurement
error is also affected by the temperature conductivity and flow velocity of the process. This self­heating error is negligible when an Endress+Hauser iTEMP temperature transmitter (very low
measured current) is used.

A0008588-EN

Endress+Hauser 11

iTHERM TM411

Response time

Response time with heat transfer paste

Tests in water at 0.4 m/s (1.3 ft/s), according to IEC 60751; 10 K temperature step change.

1)

Thermowell Shape of tip Insert

Without

thermowell

6 mm (¹⁄₄ in)

Reduced 4.3 mm (0.17 in) x

- 6 mm (¹⁄₄ in) 0.5 s 1.5 s 2.5 s 9.5 s 4 s 11.5 s 4.5 s 12 s 4.75 s 13 s

20 mm (0.79 in)

3 mm (¹⁄₈ in) 1 s 2.5 s - 8.5 s 26 s 5.5 s 18 s 8 s 23 s

Straight 6 mm (¹⁄₄ in) 2 s 9 s 8 s 27 s 15 s 45 s 15 s 45 s 9.5 s 27 s

9 mm (0.35 in)

Reduced 5.3 mm (0.21 in) x

20 mm (0.79 in)

Tapered 6.6 mm (0.26 in) x

60 mm (2.36 in)

3 mm (¹⁄₈ in) 1.25 s 4 s - 7 s 20 s 7 s 20 s 7 s 23 s

3 mm (¹⁄₈ in) 2.5 s 12 s - 14 s 49 s 12 s 40 s 15 s 51 s

Straight 6 mm (¹⁄₄ in) 4 s 26 s 12 s 54 s 23 s 81 s 23 s 81 s 31 s 100 s

12.7 mm (¹⁄₂ in)

Reduced 5.3 mm (0.21 in) x

20 mm (0.79 in)

Reduced 8 mm (0.31 in) x

32 mm (1.26 in)

3 mm (¹⁄₈ in) 1.5 s 5.5 s - 9 s 27 s 9 s 27 s 6.5 s 21 s

6 mm (¹⁄₄ in) 6 s 36 s 11 s 44 s 22 s 69 s 22 s 69 s 26 s 90 s

1x Pt100
iTHERM

QuickSens,

TF

t

50t90

1x Pt100

iTHERM

StrongSens,

TF

t

50t90

1x Pt100

wire wound

WW

t

50t90t50

2x Pt100

wire wound

WW

t

90t50t90

1x Pt100
standard

thin-film TF

1) If using a thermowell.

Response time without heat transfer paste

1)

Thermowell Shape of tip Insert

without

thermowell

6 mm (¹⁄₄ in)

-

Reduced 4.3 mm (0.17 in) x

20 mm (0.79 in)

3 mm (¹⁄₈ in)

6 mm (¹⁄₄ in) 1.5 s 2.5 s 9.5 s 4 s 11.5 s 4.5 s 12 s 4.75 s 13 s

3 mm (¹⁄₈ in) 1 s 3 s - 9 s 27 s 7.5 s 24 s 8.5 s 28 s

Straight 6 mm (¹⁄₄ in) 2 s 9 s 8 s 29 s 19 s 62 s 19 s 62 s 13.5 s 42 s

9 mm (0.35 in)

Reduced 5.3 mm (0.21 in) x

20 mm (0.79 in)

Tapered 6.6 mm (0.26 in) x

60 mm (2.36 in)

3 mm (¹⁄₈ in) 1.5 s 5 s - 7 s 21 s 7 s 21 s 8 s 22 s

3 mm (¹⁄₈ in) 5 s 23 s - 13 s 45 s 13 s 45 s 15.5 s 60 s

Straight 6 mm (¹⁄₄ in) 5.5 s 41 s 12 s 54 s 23 s 82 s 23 s 82 s 32 s 105 s

12.7 mm (¹⁄₂ in)

Reduced 5.3 mm (0.21 in) x

20 mm (0.79 in)

Reduced 8 mm (0.31 in) x

32 mm (1.26 in)

3 mm (¹⁄₈ in) 2 s 6 s - 10 s 30 s 10 s 30 s 8 s 30 s

6 mm (¹⁄₄ in) 14.5 s 65 s 16 s 53 s 26 s 85 s 26 s 85 s 32 s 108 s

1x Pt100
iTHERM

QuickSens,

TF

t

50t90

1x Pt100

iTHERM

StrongSens,

TF

t

50t90

1x Pt100

wire wound

WW

t

50t90t50

2x Pt100

wire wound

WW

t

90t50t90

0.75 s - 1.75 s 5 s 2 s 6 s 2.5 s 5.5 s

0.5 s

1x Pt100
standard

thin-film TF

1) If using a thermowell.

Response time for directly wired insert without transmitter.

12 Endress+Hauser

iTHERM TM411

Calibration

Calibration of thermometers

Calibration involves comparing the measured values of a device under test (DUT) with those of a
more precise calibration standard using a defined and reproducible measurement method. The aim is
to determine the deviation of the DUT's measured values from the true value of the measured
variable. Two different methods are used for thermometers:

• Calibration at fixed-point temperatures, e.g. at the freezing point of water at 0 °C,

• Calibration compared against a precise reference thermometer.
The thermometer to be calibrated must display the fixed point temperature or the temperature of

the reference thermometer as accurately as possible. Temperature-controlled calibration baths with
very homogeneous thermal values, or special calibration furnaces are typically used for thermometer
calibrations. The measuring uncertainty may increase due to heat conduction errors and short
immersion lengths. The existing measuring uncertainty is recorded on the individual certificate of
calibration. For accredited calibrations in accordance with ISO17025, a measuring uncertainty that is
twice as high as the accredited measuring uncertainty is not permitted. If this limit is exceeded, only
a factory calibration is possible.

Evaluation of thermometers

If a calibration with an acceptable uncertainty of measurement and transferable measurement
results is not possible, Endress+Hauser offers customers a thermometer evaluation measurement
service, if technically feasible. This is the case when:

• The process connections/flanges are too big or the immersion length (IL) is too short to allow the
DUT to be immersed sufficiently in the calibration bath or furnace (see the following table), or

• Due to heat conduction along the thermometer tube, the resulting sensor temperature generally
deviates significantly from the actual bath/furnace temperature.

The measured value of the DUT is determined using the maximum possible immersion depth and the
specific measuring conditions and measurement results are documented on an evaluation certificate.

Sensor transmitter matching

The resistance/temperature curve of platinum resistance thermometers is standardized but in
practice it is rarely possible to keep to the values precisely over the entire operating temperature
range. For this reason, platinum resistance sensors are divided into tolerance classes, such as Class
A, AA or B as per IEC 60751. These tolerance classes describe the maximum permissible deviation of
the specific sensor characteristic curve from the standard curve, i.e. the maximum temperature­dependent characteristic error that is permitted. The conversion of measured sensor resistance
values to temperatures in temperature transmitters or other meter electronics is often susceptible to
considerable errors as the conversion is generally based on the standard characteristic curve.

When using E+H temperature transmitters, this conversion error can be reduced significantly by
sensor-transmitter matching:

• Calibration at three temperatures at least and determination of the actual temperature sensor
characteristic curve,

• Adjustment of the sensor-specific polynomial function using Calendar-van Dusen (CvD)
coefficients,

• Configuration of the temperature transmitter with the sensor-specific CvD coefficients for
resistance/temperature conversion, and

• another calibration of the reconfigured temperature transmitter with connected resistance
thermometer.

Endress+Hauser offers its customers this kind of sensor-transmitter matching as a separate service.
Furthermore, the sensor-specific polynomial coefficients of platinum resistance thermometers are
always provided on every Endress+Hauser calibration certificate where possible, e.g. at least three
calibration points, so that users themselves can also appropriately configure suitable temperature
transmitters.

For the device, Endress+Hauser offers standard calibrations at a reference temperature of
–80 to +600 °C (–112 to +1 112 °F) based on the ITS90 (International Temperature Scale).
Calibrations in other temperature ranges are available from your Endress+Hauser sales center on
request. Calibrations are traceable to national and international standards. The calibration certificate
is referenced to the serial number of the device. Only the insert is calibrated.

Minimum insertion length (IL) for inserts required to perform a correct calibration

Due to the limitations of furnace geometries, the minimum insertion lengths must be observed
at high temperatures to enable a calibration to be performed with an acceptable degree of
measuring uncertainty. The same applies when using a head transmitter. Due to heat
conduction, minimum lengths must be observed in order to guarantee the functionality of the
transmitter –40 to +85 °C (–40 to 185 °F)

Endress+Hauser 13

iTHERM TM411

IL

IL*

ΔL

Calibration temperature Minimum insertion length IL in mm without head transmitter

–196 °C (–320.8 °F) 120 mm (4.72 in)

–80 to 250 °C (–112 to 482 °F) No minimum insertion length required

251 to 550 °C (483.8 to 1 022 °F) 300 mm (11.81 in)

551 to 600 °C (1 023.8 to 1 112 °F) 400 mm (15.75 in)

1) Min. 150 mm (5.91 in) required with TMT

2) At a temperature of +80 to +250 °C (+176 to +482 °F) and with TMT, min. 50 mm (1.97 in) is required

1)

2)

A0018625

 2 Insertion lengths for sensor calibration

IL Insertion length for factory calibration or recalibration onsite without the iTHERM QuickNeck extension neck
IL* Insertion length for recalibration onsite with the iTHERM QuickNeck extension neck
ΔL Additional length, depending on the calibration unit, if the insert cannot be fully immersed

• To check the actual accuracy rating of the thermometers installed, a cyclic calibration of the
installed sensor is frequently performed. The insert is normally removed for comparison with a
precise reference thermometer in the calibration bath (see graphic, left part).

• The iTHERM QuickNeck enables quick, tool-free removal of the insert for calibration purposes. The
entire upper part of the thermometer is released by turning the terminal head. The insert is
removed from the thermowell and directly immersed into the calibration bath (see graphic, right
part). Make sure that the cable is long enough to be able to reach the mobile calibration bath with
the cable connected. If this is not possible for the calibration, it is advisable to use a connector.
→  34

Advantages of iTHERM QuickNeck:

• Considerable time savings when recalibrating the device (up to 20 minutes per measuring point)

• Wiring mistakes avoided when re-installing

• Minimum plant downtime, thereby saving costs

Formulas for calculating the IL* when recalibrating onsite with iTHERM QuickNeck

Version, with M24x1.5 or NPT ½" thread to terminal head Formula

Thermowell diameter 6 mm (¹⁄₄ in) IL* = U + T + 5 mm (0.2 in)

Thermowell diameter 9 mm (0.35 in) IL* = U + T - 25 mm (0.98 in)

Thermowell diameter 12.7 mm (¹⁄₂ in) IL* = U + T + 5 mm (0.2 in)

Insulation resistance

Insulation resistance ≥ 100 MΩ at ambient temperature.

Insulation resistance between the terminals and the outer jacket is measured with a minimum
voltage of 100 V DC.

14 Endress+Hauser

iTHERM TM411

U

≥ 3°

≥ 3°

1

2

3

4

Installation

Orientation

Installation instructions

No restrictions. However, self-draining in the process must be guaranteed. If there is an opening to
detect leaks at the process connection, this opening must be at the lowest possible point.

The immersion length of the thermometer can influence the accuracy. If the immersion length is too
small then errors in the measurement are caused by heat conduction via the process connection and
the container wall. If installing into a pipe then the immersion length should ideally be half of the
pipe diameter.

• Installation possibilities: Pipes, tanks or other plant components

• To minimize the error caused by heat conduction, a minimum immersion length is recommended
depending on the type of sensor used and the design of the insert. This immersion depth
corresponds to the minimum insertion length for the calibration.

• ATEX certification: Observe the installation instructions in the Ex documentation! →  51

A0008946

 3 Installation examples

1, 2 Perpendicular to flow direction, installed at a min. angle of 3° to ensure self-draining
3 On elbows
4 Inclined installation in pipes with a small nominal diameter
U Immersion length

In the case of pipes with a small nominal diameter, it is advisable for the tip of the thermometer
to project well into the process so that it extends past the pipe axis. Installation at an angle (4)
could be another solution. When determining the immersion length or installation depth all the
parameters of the thermometer and of the medium to be measured must be taken into account
(e.g. flow velocity, process pressure).

For immersion lengths U < 70 mm (27.5 in), the use of iTHERM QuickSens inserts is
recommended..

Endress+Hauser 15

iTHERM TM411

1 2

1 2

3

4

R0.4

R0.4

Pressure ring

Sensor with
milk pipe
connection

Sensor with Varivent
connection

Shaped
gasket

Companion
connection

O-ring

Groove
slip-on nut

Centering ring

Sealing

Companion
connection

Companion
connection

O-ring

Welding boss

Vessel wall

 4 Process connections for thermometer installation in pipes with small nominal diameters

1

Varivent® process connection type N for DN40

2 Corner-piece or T-piece (illustrated) for weld-in as per DIN 11865 / ASME BPE

A0008947

 5 Detailed installation instructions for hygiene-compliant installation

1 Sanitary connection according to DIN 11851, only in conjunction with self-centering sealing ring as per

EHEDG position paper

2

Varivent® process connection for VARINLINE® housing
3 Clamp as per ISO 2852, only in conjunction with seal as per EHEDG position paper
4 Process connection Liquiphant-M G1", horizontal installation

The counterpieces for the process connections and the seals or sealing rings are not included in
the scope of supply for the thermometer. Liquiphant M weld-in adapters with associated seal
kits are available as accessories. →  47.

The following action must be taken if a sealing ring (O-ring) or seal fails:

• Remove the thermometer, clean the thread and the O-ring joint/sealing surface

• Replace the sealing ring or seal

• Perform CIP after installation
In the case of weld-in connections, exercise the necessary degree of care when performing the

welding work on the process side:

• Suitable welding material

• Flush-welded or with welding radius >= 3.2 mm (0.13 in)

• No recesses, folds or gaps

• Honed and polished surface, Ra ≤ 0.76 µm (30 µin)
As a general rule, the thermometers should be installed in such a way that does not impact

their ability to be cleaned (the requirements of the 3-A® Standard must be observed). The
Varivent®, Liquiphant M weld-in adapter and Ingold (+ weld-in adapter) connections enable

16 Endress+Hauser

flush-mounted installation.

A0011758-EN