Endress+Hauser TMS21 iTHERM MultiSens Slim Multipoint

Endress+Hauser TMS21 iTHERM MultiSens Slim thermocouple multipoint probe

The TMS21 is the iTHERM MultiSens Slim, a minimally invasive thermocouple multipoint thermometer for petrochemical and chemical process units. A small-diameter thermowell holds many fine metal-sheathed thermocouples, so a vessel or tank gets a detailed profile through a small nozzle. The manufacturer quotes as many as 59 measuring points in one probe. Because the sensing elements are thin and the thermowell is slim, the response is fast and the probe disturbs the process little.

It is also the easiest of the multipoint roots to fit: the process connection is normally a compression fitting, with an ASME or EN flange on request, and the signal cables leave through a flexible conduit. Seven Star LLC, an independent supplier in Muscat, quotes the TMS21 across Oman and the GCC for light chemical duties, tank temperature profiling and furnace-adjacent monitoring where a rigid heavy assembly is not wanted.

TMS21 technical specifications

The inserts of a TMS21 are not replaceable, so sensor choice and redundancy are decided at the ordering stage.

How many sensors fit: the TMS21 thermowell and insert matrix

The number of measuring points is limited by geometry. The datasheet table shows the maximum inserts for each pairing of thermowell and insert diameter.

The 46- and 59-point combinations need a specially engineered main bushing. For redundancy, duplicate measuring-point sensors can be ordered for sensor backup, and a dual-channel TMT8x transmitter improves monitoring.

Linear and flexible TMS21 configurations

Two layouts are offered. The linear configuration uses a straight thermowell for a profile along one axis. The flexible configuration adds a corrugated, bendable section in the thermowell, which is the answer when the nozzle and the desired measuring path do not line up. A reinforcing sleeve slides in the compression fitting or flange to set the immersion length, while the main bushing seals the junctions between the thermocouples and the extension cables.

The thermowell is made of annealed tube in 316/316L, with 321 or 347 also in the materials list. Where the process medium is aggressive, ask for the right alloy and flange plating, since the datasheet notes special-alloy plating on flanges is available.

Compatible parts and neighbouring Endress+Hauser roots

Next to the TMS21 sit the TMS01 and TMS02 flexible multipoints, the TMS11 with primary thermowell, and the single-point roots used for spares. Junction boxes and transmitters are accessories that can be ordered separately to fit equipment already installed on site. The TMT8x dual-input head transmitter, HART or fieldbus options and the iTEMP family appear in the wiring section of the datasheet, and HAW surge arresters protect signal lines in hazardous areas.

Selection and ordering checklist for the TMS21

• Thermocouple type: N or K for high temperature, J or E for lower ranges with higher output.
• Insert diameter and tolerance class, keeping in mind the temperature limit falls with smaller diameters.
• Number of points and their spacing along the probe, checked against the thermowell and insert matrix.
• Thermowell diameter, material and whether the flexible version is needed.
• Immersion length (up to 13 m on request) and the nozzle that the probe passes through.
• Process connection: compression fitting or flange, with standard, size and rating.
• Extension conduit and cable type, plus junction box and transmitters if needed.
• Hazardous-area classification, since the Ex version is limited to 20 sensors.

Installing and caring for the TMS21

The probe is installed through a compression fitting, so avoid over-tightening it. Deformation of threads, nuts, glands or fittings is the common failure mode named in the installation notes. Route the flexible conduit away from heat sources and sharp edges; its polyamide or metal sheath is there to resist abrasion, moisture and salt. Keep the bend radius generous on the flexible thermowell so that the sensors are not strained. Checks at commissioning include comparing each point at a stable temperature, which the manufacturer lists as a functional test, and a thermal-excitation test when response of each point is critical.

TMS21 applications in the Gulf

The TMS21 suits batch reactors, storage tanks that need stratification monitoring, dryers, silos and furnace walls in chemical and petrochemical sites across Oman and the GCC. In regions with high ambient temperatures the compact format helps because the conduit can be routed to a shaded junction box. For tank-farm monitoring in desalination and fuel storage, the many-point format spots hot layers and cold spots that single-point readings miss.

Information to send with a TMS21 RFQ

• Vessel type, tag and nozzle size, plus the maximum immersion length needed.
• Number and position of measuring points, and thermocouple type.
• Operating and design temperature and pressure, and the process fluid.
• Linear or flexible layout, thermowell diameter and material.
• Process connection style and any flange standard.
• Junction box, transmitter or terminal-block requirements and hazardous-area rating.
• Quantity and delivery point in Oman or the GCC.

Documents and quotation

The official Endress+Hauser technical information for the TMS21 is attached on this page as a PDF. It includes the sensor-count table and the temperature limits for each thermocouple. It is the reference for ranges, dimensions, materials and process-connection limits, so check your own configuration against it before you commit to a purchase.

Seven Star LLC is an independent supplier based in Muscat and supplies industrial instrumentation in Oman and the GCC. Send us the TMS21 configuration you need, the tag or datasheet line it must match and the delivery location, and we will reply with availability and a quotation.