Endress+Hauser TM411 iTHERM Hygienic RTD Thermometer

Endress+Hauser TM411 iTHERM ModuLine hygienic RTD thermometer

The Endress+Hauser TM411 is the metric hygienic member of the iTHERM ModuLine thermometer family. It is an RTD thermometer built for hygienic and aseptic process lines, mainly in food and beverage and life-science plants, and it can be ordered with or without a thermowell. The datasheet gives a measuring range of –200 to +600 °C, a pressure range up to 50 bar and ingress protection up to IP69K, the level that survives high-pressure wash-down.

Seven Star LLC supplies the TM411 in Oman and the GCC as an independent supplier in Muscat. Because the TM411 is a configurable model rather than a single catalogue item, the sensor, thermowell tip, process connection, neck and head are agreed at quotation stage.

In the manufacturer naming scheme, TM4 marks the hygienic line. The last digit tells you the technology level: TM41x uses a replaceable insert, the quick-release iTHERM QuickNeck, the fast and vibration-resistant sensor options and hazardous-area approval, while TM40x is the basic version with a fixed insert for non-hazardous areas. The final digit separates units: TM411 is metric (mm), TM412 is the imperial (inch) equivalent. So the TM411 is the full-featured metric variant.

TM411 technical specifications

How the TM411 measures and what sets it apart

The sensing element is a Pt100 platinum resistor: 100 Ω at 0 °C with a temperature coefficient of 0.003851 per °C. Two element constructions are available. Wire-wound elements are very reproducible and stable up to 600 °C but larger and more sensitive to shock. Thin-film elements are smaller and tougher. The datasheet notes that thin-film sensors drift slightly from the standard curve at higher temperature, so tolerance class A is only held up to about 300 °C with them.

Two insert technologies matter for hygienic lines. iTHERM QuickSens is a small-diameter thin-film insert, 3 or 6 mm, designed for the shortest response; in the smallest reduced-tip thermowell with heat-transfer paste the datasheet lists a t90 of about 2.5 s, and the 1.5 s figure is the best case. iTHERM StrongSens is built to keep reading under vibration above 60g, which suits pumps, mixers and filling machines. The inserts are replaceable, and the QuickNeck fastener lets a technician pull the insert for recalibration without tools, which the manufacturer states cuts recalibration time by up to 75 percent.

Hygienic design, cleaning and approvals of the TM411

Hygiene is the reason to choose this model over an industrial thermometer. The datasheet lists process connections that carry 3-A marking and EHEDG certification, ASME BPE compliance on indicated options, and food-contact material conformity with the relevant EU regulations. It also states FDA compliance and that product-contact surfaces contain no animal-derived ingredients. Housings are specified as resistant to a list of common Ecolab cleaning and disinfection agents plus demineralised water.

• EHEDG type EL class I for certified connections; 3-A authorization no. 1144 for listed connections
• Surface options: mechanically polished, buffed, or buffed plus electropolished (the buffed-only option is not ASME BPE compliant)
• Optional oil- and grease-free cleaning and PWIS-free finish; CRN only on certain thermowell versions

Only claim an approval for a purchase once it is shown on the quoted configuration; the datasheet states that approvals are available per product code.

Process connections and thermowell options for TM411

More than 50 connection versions are available, so confirm the standard used on your skids. The datasheet groups them as follows.

• Aseptic pipe unions to DIN 11864-1 Form A, DN25 and DN40, rated 40 bar, 3-A and EHEDG listed
• Weld-in adapters in five shapes: cylindrical 12.7 mm, cylindrical 12 by 40 mm or 30 by 40 mm, spherical-cylindrical 30 by 40 mm, and spherical 25 mm
• Releasable metal-sealing and compression-fitting versions for pipework with small nominal diameters
• Thermowell diameters 6, 9 and 12.7 mm, with straight, reduced or tapered tips; the reduced tip is the fast one and the straight tip is the stiffer one

Thermowell choice drives response time. A 6 mm straight tip with a QuickSens 6 mm insert is listed at roughly 2 s to t50 and 9 s to t90, while a heavier 12.7 mm straight tip is slower. Specify the tip shape together with the immersion length so the response matches your control loop.

Selection and ordering checklist for the TM411

The TM411 reaches the control system as a raw Pt100 or through an iTEMP head transmitter. Related models: TM412 is the inch twin, TM401 and TM402 are the basic fixed-insert versions, and TM131, TM151, TM152, TM111 and TM121 are the industrial models.

• Process media, maximum CIP/SIP temperature and steam-out conditions
• Pipe size and the hygienic connection standard (DIN 11864, clamp, weld-in)
• With or without thermowell; thermowell diameter, tip shape and immersion length U
• Sensor type: standard thin-film, QuickSens, StrongSens or wire-wound; single or dual element
• Accuracy class A or AA and whether a calibration certificate is needed
• Extension neck: welded or QuickNeck; neck length
• Head material (316L, aluminium, polypropylene, polyamide), display window, cable gland or M12 plug
• Transmitter or direct wiring, output protocol and hazardous-area approval
• Surface finish, material certificates, oxygen-clean or PWIS-free requirement

Installation, commissioning and maintenance of the TM411

Install the thermowell in a position with good flow and, if possible, at an elbow facing the flow so that the sensor tip sees the process temperature rather than the pipe wall. Keep the thermowell free of dead legs; that is the whole point of the hygienic connection. The datasheet recommends checking the mechanical load of the thermowell at your flow velocity with the sizing tool in the manufacturer applicator software.

Spares are ordered by instrument serial number, because the insertion length is derived from it. Calibrate inserts against a reference at fixed points or in a bath and record the deviation so drift can be trended. The QuickNeck rates to +140 °C, and a head with transmitter must stay within –40 to +85 °C ambient.

TM411 applications in Oman and the GCC

Hygienic RTDs are used wherever temperature is a quality parameter. In Oman and the GCC the typical homes are dairy and juice plants, bottled water and beverage filling, bakery and food processing, pharmaceutical and cosmetics production, and the hygienic utilities of large hospitals and hotels. Pasteurisers, heat exchangers, CIP return lines and sterilisers are the classic measuring points.

Hot, dusty and humid conditions argue for the stainless head, the IP69K sealing and a reduced thermal path through the neck. Where equipment sits outdoors on a sun-exposed skid, keep the transmitter inside its rated ambient limit by choosing a shaded head position or a longer neck.

Information to send with a TM411 request for quotation

• Tag number, service and the P&ID or loop sketch
• Process medium, normal and maximum temperature, pressure and CIP/SIP cycle
• Connection type and size, thermowell diameter, tip shape and immersion length
• Insert type, accuracy class, calibration needs
• Head, transmitter and output protocol; hazardous-area zone if any
• Required certificates: material, surface, hygienic approvals
• Quantity and delivery location in Oman or the GCC

Documents and quotation

The manufacturer technical information for the TM411 is attached to this page. Read it together with your project specification, because the thermowell, sensor, head and transmitter options that apply to your tag are fixed by the order configuration, not by the model name alone. Approvals and ratings should always be checked against the exact configuration that is quoted.

Seven Star LLC quotes against your data sheet or loop drawing and confirms lead time, stock position and the documents that ship with the instrument. Send us the details listed above and we will respond with a priced offer for delivery in Oman and the wider GCC.