iTherm Moduline TM151

Summary

Product Identification

The iTHERM ModuLine TM151 is a highly modular and robust RTD or TC thermometer designed for a wide range of industrial applications.

Application

• Universal use
• Measuring range: –200 to +1 100 °C (–328 to +2 012 °F)
• Pressure range up to 500 bar (7 252 psi)
• Vibration-resistant sensor elements up to 60g
• Features improved ease of maintenance, allowing sensor replacement without process shutdown and simplifying recalibration.

Measuring Principle

The device can utilize either Resistance Thermometers (RTD) or Thermocouples (TC).

Resistance Thermometers (RTD)

• Utilizes Pt100 temperature sensors according to IEC 60751.
• Resistance is 100 Ω at 0 °C (32 °F) with a temperature coefficient α = 0.003851 °C⁻¹.
• Available sensor types:
  • Wire-wound (WW): Suitable for temperatures up to 600 °C (1 112 °F), but sensitive to vibrations.
  • Thin-film (TF): Smaller size and better vibration resistance, but may deviate from IEC 60751 at higher temperatures.

Thermocouples (TC)

• Based on the Seebeck effect, measuring temperature differences.
• Standardized types include K, J, and N according to IEC 60584 and ASTM E230/ANSI MC96.1.

Modular Design

The thermometer features a modular design allowing for various configurations:

• Terminal Head: Available in aluminum, polyamide, or stainless steel with options for a local display.
• Wiring/Electrical Connection/Output Signal: Supports ceramic terminal blocks or flying leads. Head transmitters offer analog output (4-20 mA, HART®), PROFIBUS® PA, FOUNDATION™ Fieldbus™, PROFINET over Ethernet-APL, and IO-Link®.
• Plug or Cable Gland: Options include polyamide or brass cable glands, M12 plugs (4-pin/8-pin), and 7/8" plugs.
• Extension Neck: Options include standard DIN 43772, iTHERM QuickNeck for tool-free removal, and extensions with a second process seal.
• Lagging: Provides space between the thermometer connection and process connection.
• Process Connection: Various options including threads, flanges (EN or ASME), and socket weld.
• Thermowell: Available with or without thermowells, with options for different diameters, materials, and tip shapes.
• Insert: Options include:
  • iTHERM QuickSens: For fast response times (1.5 s).
  • iTHERM StrongSens: For high vibration resistance (≤ 60g).
  • Central-spring-loaded insert.
  • Sensor types: RTD (wire wound or thin-film) or thermocouples (K, J, N).

Input

Measured Variable

• Temperature (temperature linear transmission behavior)

Measuring Range

The measuring range depends on the specific sensor type used:

• Pt100 thin-film (TF), basic: –50 to +200 °C (–58 to +392 °F)
• Pt100 thin film (TF), standard: –50 to +400 °C (–58 to +752 °F)
• Pt100 thin film (TF), iTHERM StrongSens: –50 to +500 °C (–58 to +932 °F)
• Pt100 wire wound (WW), extended: –200 to +600 °C (–328 to +1 112 °F)
• Thermocouple TC, type J: –40 to +750 °C (–40 to +1 382 °F)
• Thermocouple TC, type K: –40 to +1 100 °C (–40 to +2 012 °F)
• Thermocouple TC, type N: (Measuring range not specified in extract)

Output

The measured value can be transmitted directly-wired or via an Endress+Hauser iTEMP transmitter.

Output Signal

• Analog output: 4 to 20 mA, HART® (optional SIL transmitter available)
• Digital communication protocols: PROFIBUS® PA, FOUNDATION™ Fieldbus™, PROFINET over Ethernet-APL, IO-Link®.

Family of Temperature Transmitters

iTEMP transmitters offer enhanced accuracy and reliability. They can be configured using PC software.

• HART® head transmitters: 2-wire device with optional Bluetooth® interface.
• PROFIBUS® PA head transmitters: Universally programmable for digital output signals.
• FOUNDATION Fieldbus™ head transmitters: Universally programmable for digital output signals.
• PROFINET® and Ethernet-APL head transmitter: 2-wire device, usable in Zone 1 hazardous areas.
• IO-Link® head transmitter: Digital communication via IO-Link®.

Power Supply

Sensor connection wires are equipped with terminal lugs (nominal diameter 1.3 mm / 0.05 in).

Terminal Assignment

Detailed terminal assignment diagrams are provided for RTD and thermocouple connections, supporting various wiring configurations (2-, 3-, and 4-wire for RTDs) and different head-mounted transmitters (TMT7x, TMT31, TMT36, TMT8x, TMT162, TMT142B).

Performance Characteristics

Reference Conditions

Data relevant for determining transmitter accuracy; details are in the relevant Technical Information.

Maximum Measurement Error

Tolerances for RTD resistance thermometers as per IEC 60751:

• Class A: ± (0.15 + 0.002 · |t| °C)
• Class AA (1/3 Cl. B): ± (0.1 + 0.0017 · |t| °C)
• Class B: ± (0.3 + 0.005 · |t| °C)

Operating temperature ranges for different classes and sensor types are provided.

Influence of Ambient Temperature

Depends on the head transmitter used.

Self-Heating

Negligible when using an Endress+Hauser iTEMP transmitter due to a very small measurement current.

Calibration

• Involves comparing the Unit Under Test (UUT) against a calibration standard.
• Methods include fixed-point temperatures and comparison with a reference thermometer.
• Evaluation service is available if a correct calibration is not technically feasible.
• Sensor-transmitter matching is offered to reduce conversion errors, using Callendar-van Dusen (CvD) coefficients.
• Standard calibrations are based on ITS90.

Insulation Resistance

• RTD: > 100 MΩ at 25 °C between terminals and sheath material (min. 100 V DC).
• TC: > 1 GΩ at 20 °C and > 5 MΩ at 500 °C between terminals and sheath material (500 V DC).

Installation

Orientation

No restrictions, but self-draining should be considered.

Installation Instructions

The immersion length of the thermometer influences measurement accuracy. Recommendations are provided for installation in pipes and angled orientations.

Ambient Conditions

Ambient Temperature Range

• Terminal head (without transmitter): Depends on head and cable gland/connector.
• Terminal head (with transmitter): –40 to +85 °C (–40 to +185 °F).
• Terminal head (with transmitter and display): –20 to +70 °C (–4 to +158 °F).

Humidity

• Condensation permitted as per IEC 60 068-2-33.
• Max. relative humidity: 95% as per IEC 60068-2-30 (when using iTEMP transmitters).

Climate Class

As per EN 60654-1, Class C.

Degree of Protection

• Max. IP 66 (NEMA Type 4x encl.).
• Partly IP 68.

Shock and Vibration Resistance

• Inserts exceed IEC 60751 requirements (3g, 10-500 Hz).
• Specific resistance levels vary by sensor type:
  • Pt100 (WW), Thermocouple inserts: ≤ 30 m/s² (3g)
  • Pt100 (TF), basic/standard: ≤ 40 m/s² (4g)
  • iTHERM StrongSens Pt100 (TF): ≤ 600 m/s² (60g)
  • iTHERM QuickSens Pt100 (TF) (⌀6 mm): ≤ 600 m/s² (60g)
  • iTHERM QuickSens Pt100 (TF) (⌀3 mm): ≤ 30 m/s² (3g)

Electromagnetic Compatibility (EMC)

Depends on the head transmitter used.

Process

Process Temperature Range

• Max. –200 to +1 100 °C (–328 to +2 012 °F).
• For fast-response thermowell: max. –200 to +400 °C (–328 to +752 °F).

Process Pressure Range

The maximum pressure depends on design, connection, and temperature. Specific values for individual process connections are detailed in the "Process connection" section. Flow velocity tolerance diminishes with increasing immersion length.

Process Connection

• Weld-in/Socket weld: ≤ 500 bar (7 252 psi).
• Flange (EN/ASME/JIS): Pressure rating varies by standard and class.
• Thread (ISO/ANSI/DIN/JIS):
  • 140 bar (2 031 psi) at +40 °C (+140 °F).
  • 85 bar (1 233 psi) at +400 °C (+752 °F).

Mechanical Construction

Design, Dimensions

Dimensions are variable depending on the configuration (e.g., immersion length U, lagging length T, extension neck length E). Various connection types are available based on ASME, DIN, and NAMUR standards.

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Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror