Product picture of Thermometer with RTD or TC insert TM121

iTHERM ModuLine TM121
Industrial modular thermometer

Fundamental metric RTD/TC thermometer with protection tube for a wide range of industrial applications

TM121

Compare

Specs at a glance

Accuracy

Class A acc. to IEC 60751
Class B acc. to IEC 60751
Class standard acc. to ASTM E230
Class 2 acc. to IEC 60584-2
Response time

t90 around 100 s
depending on configuration
Max. process pressure (static)

depending on the configuration
Operating temperature range

Basic PT100 TF:
-50 °C …200 °C
(-58 °F …392 °F)
Typ K:
max. 1.100 °C
(max. 2.012 °F)
Max. immersion length on request

up to 1.000,0 mm (39'')

See all specifications

Field of application

iTHERM ModuLine TM121 is a modular metric RTD or TC thermometer with protection tube or to be used with onsite thermowell. With best price-performance ratio it is suitable for basic measurement tasks in non-hazardous areas across all industries.

For universal use across all industries: Ideal for standard applications and use in non-hazardous areas.
iTEMP temperature transmitter with widely used communication protocols (4–20 mA, HART, IO-Link).

Benefits

Modular configuration for all applications: A wide selection of components, all combined under a single order code.
Excellent price-performance ratio: Purpose-built, reliable temperature measurement with basic features.

Loading alternative products

Predecessor

Success stories

Saving energy with smart e-boiler monitoring

Boosting sustainability with real-time energy insights
Read the full story
Using methanol safely and efficiently

Using methanol safely and efficiently - Everllence relies on smart measurement technology from Endress+Hauser
Read the full story
Non-invasive thermometer streamlines calibration

Fast, non‑invasive temperature measurement without removing insulation for calibration: iTHERM SurfaceLine TM611 cuts downtime, improves safety and delivers accurate results even in hazardous areas.
Read the full story
High-quality instrumentation for cooling water systems

Torishima designs and builds large cooling water systems for customers in the Middle East, relying on Endress+Hauser instrumentation for the quality and performance of the products.
Read the full story
Maximize yield, minimize downtime

Maximize yield, minimize downtime - Smart temperature monitoring in High-Pressure Acid (HPAL) Leaching processes
Read the full story

Simple products
Easy to select, install and operate

Technical excellence

Simplicity

What is FLEX?

Standard products
Reliable, robust and low-maintenance

Technical excellence

Simplicity

What is FLEX?

High-end products
Highly functional and convenient

Technical excellence

Simplicity

What is FLEX?

Specialized products
Designed for demanding applications

Technical excellence

Simplicity

Variable

What is FLEX?

FLEX selections	Technical excellence	Simplicity
F L E X Fundamental selection Meet your basic measurement needs	Technical excellence	Simplicity
F L E X Lean selection Handle your core processes easily	Technical excellence	Simplicity
F L E X Extended selection Optimize your processes with innovative technologies	Technical excellence	Simplicity
F L E X Xpert selection Master your most challenging applications	Technical excellence	Simplicity Variable

Learn more about the FLEX selections

Could also interest you

Media
eBrochure iTHERM ModuLine

Explore iTHERM ModuLine industrial thermometers and thermowells. Learn more about the technical differences between the different models and discover included Endress+Hauser innovations.
More information
Products
iTHERM ModuLine.
Modular by design. Tailored to your needs.

iTHERM ModuLine offers full flexibility for industrial temperature measurement. The modular industrial thermometers can be configured individually to meet your process requirements.
More information

Quick selection

Choose from our suggested options

Sales price

<%label%>
-- selected coding

-- selected label

99.999,00
<%label%>
Looking for more options? Please use the individual configurator to continue
<%feature%>
-- selected coding

-- selected label

99.999,00
<%feature%>
<%coding%>

<%label%>

99.999,00

Looking for more options? Please use the individual configurator to continue
Process Connection
<%coding%>

<%label%>

99.999,00

<%coding%>

<%label%>

99.999,00

<%message%>

TM121

Show details Hide details

Show details

Back

<%feature%>

<%coding%>

<%label%>

CAD drawings CAD drawings

Available once configuration is complete

Service not available

CAD drawings

CAD drawings are only available on our desktop experience

Optional add-ons

Please use the individual configurator to continue

Individual configuration

Continue your selection from all possible options

Often bought together

Accessories

Fixing kit cpl. TMT8x/7x (european)

Thermo-conductive paste FDA-conform 30g

See more accessories

Language:	Russian
Version:	03/02/2023
File size:	567.7 KB
File name:	1942 TM1x1.pdf

Language:	Russian
Version:	12/08/2022
File size:	3 MB
File name:	02-2.0170 12.07.2027.pdf

	EN
12/05/2025
31/03/2024
15/06/2022
31/03/2021
15/04/2019

Language:	English
Version:	12/05/2025
File size:	2 MB
File name:	TI01455TEN_0525-00.pdf

Language:	English
Version:	04/08/2025
File size:	809.1 KB
File name:	BA01915TEN_0325-00.pdf

	EN
04/08/2025
30/11/2024

	EN
01/04/2025

	EN
17/11/2025

	EN
01/01/2024

iTHERM ModuLine TM121Industrial modular thermometer

Fundamental metric RTD/TC thermometer with protection tube for a wide range of industrial applications

Specs at a glance

Accuracy

Response time

Max. process pressure (static)

Operating temperature range

Max. immersion length on request

Field of application

Benefits

Predecessor

Success stories

Saving energy with smart e-boiler monitoring

Using methanol safely and efficiently

Non-invasive thermometer streamlines calibration

High-quality instrumentation for cooling water systems

Maximize yield, minimize downtime

Could also interest you

eBrochure iTHERM ModuLine

iTHERM ModuLine. Modular by design. Tailored to your needs.

Measuring principle

Characteristic / Application

Thermowell / protection tube

Insert / probe

Outer diameter protection tube / Insert

Max. immersion length on request

Material protection tube/ thermowell

Process connection

Tip shape

Operating temperature range

Max. process pressure (static)

Accuracy

Response time

Integration head transmitter

Back

Product family: Process RTD general purpose

Product family: DIN rail transmitter, Field transmitter, Head transmitters, Process RTD general purpose, Process TC direct in contac t

TI iTHERM ModuLine TM121

BA iTHERM ModuLine thermometer

KA iTHERM ModuLine thermometer

iTEMP TMT72 Transmitter HART

EA Austausch Anschlussblock

iTEMP TMT36, Transmitter IO-Link

Feldgehäuse TA30A

Feldgehäuse TA20AB

iTEMP TMT71, Transmitter 4-20mA

Information Typenschild DIENST-T

Back

Terminal Head TA30A

Spare parts kit sealing TA30A/TA30D

Terminal Head TA30EB

Spare parts kit o-ring (silicon) 71x3

Terminal Head TA20AB

Plug for Thermometer + Transmitter

Cable gland NPT1/2, D4.5-8.5 IP68

Cable entry M20x1.5

Adapter M20x1.5 exter./M24x1.5 intern.VA

iTEMP TMT31, Transmitter 4-20mA

iTEMP TMT36, Transmitter IO-Link

iTEMP TMT71, Transmitter 4-20mA

iTEMP TMT72, Transmitter HART

Display Unit Head Transmitter

TID10 Service cable

Configuration Kit TXU10

Commubox FXA291 (Hardware)

FieldPort SFP20

M12 cable for FieldPort SFP20

iTHERM Insert TS111

Term.block DIN B (42mm) 2 term. Spc 5 pc

Term.block DIN B (42mm) 3 term. 5 pc

Term.block DIN B (42mm) 4 term. 5 pc

Term.block DIN B (42mm) 6 term. 5 pc

Compression Fitting TK40

Spare Parts Kit Seal Insert TK40

Spring-loaded compr. fitting G1/2 compl.

Spring-loaded compr. fitt. NPT1/2 compl.

iTHERM ModuLine TT131

Spare parts kit ring D21/di 10xgreen

Spare parts kit gasket ring D21/d6 Viton

Spare parts kit gasket ring D21/d6 Neop.

iTHERM ModuLine TM121
Industrial modular thermometer

iTHERM ModuLine.
Modular by design. Tailored to your needs.