JUMO 901210 Mineral-Insulated Thermocouple with Flexible Sheath Cable, Bare Wires

A flexible mineral-insulated thermocouple for hard-to-reach points

The JUMO 901210 is a mineral-insulated thermocouple with bare connection wires, the basic member of a family described in data sheet 901250 to DIN 43710 and DIN EN 60584. It measures temperatures in liquids and gases and, thanks to a flexible sheath cable with a vibration-resistant measuring insert, suits hard-to-reach places in machines and systems. JUMO names the chemical industry, power plants, mechanical and plant engineering, engine manufacturing, testing and laboratory technology, and container and pipeline construction. Response is quick, and SIL and PL qualification is available through extra code 658.

The sheath diameters run from 0.5 to 6 mm, which sets both the response time and the temperature limit. In water at 0.4 m/s a 0.5 mm sheath reaches t0.9 in about 0.30 s and a 6 mm sheath in about 9 s; in air at 2 m/s the figures are roughly 8 s and 170 s. Insert types are Fe-CuNi J and L (to +800 degC), NiCr-Ni K and NiCrSi-NiSi N (to +1200 degC), as single or, on most sizes, double thermocouples.

Technical specifications

Specifying the 901210 thermocouple: type, sheath and length

The order code is basic type – measuring insert – sheath diameter – insertion length / extra codes. The example is 901210/10 – 1042 – 3 – 200 / 000, a single type L element in a 3 mm sheath of 200 mm. The wider data sheet also defines screw-in and push-in versions with form B or form J heads (901220/40, /41 and 901230/40, /41), a version with a thermal-voltage-free tab connector (901240/20) and a version with connecting cable (901250). Type N is limited to sheath sizes of 1.5, 3 and 6 mm in single form and 3 and 6 mm in double form.

Extra codes for DAkkS or 3.1 certificates and for AMS 2750, CQI-9 and ISO 20431 accuracy are listed with the conditions printed in the datasheet. Terminal heads and bases are described in data sheet 909715 and general thermocouple background in data sheet 901000.

Using flexible mineral-insulated sensors in plant

The metal sheath can be bent to a minimum radius, which allows routing into engine blocks, exhaust paths, heat exchangers and test rigs where a rigid probe would not fit. Mineral insulation (compacted oxide) keeps the thermocouple wires dry and aligned and gives a thermally fast, vibration-tolerant element. The bend radius should not be smaller than the data sheet allows (general guidance is several sheath diameters). The thinnest sheaths respond very fast but carry high loop resistance, so keep the run to the instrument short or use a transmitter.

Fit the sheath through a compression fitting (data sheet 909750) or weld sleeve, and keep the adapter end closure within its temperature limit of 120 degC, or 300 degC with the high-temperature closure. Connect with the correct compensating cable and polarity for the element type. Typical uses in the region include gas turbine and engine exhaust monitoring, process furnaces, heat-treatment test thermocouples, boiler tubes and laboratory calibration baths.

As general guidance, record the order code printed on the nameplate before requesting a quotation, and keep the data sheet revision with the project documents so that later replacements match the installed device. Tell us the quantity, the delivery location in Oman and any wiring or mounting accessories you also need, and we will confirm availability and lead time for the exact variant.

Documents and quotation

The JUMO data sheet 901250 (covering 901210 to 901250) is attached. Seven Star LLC supplies JUMO thermocouples from Muscat; state the element type, sheath diameter, insertion length and extra codes and we will quote. See https://omansevenstar.com/product-category/sensors-transmitters/temperature/ for other temperature probes.