JUMO 902090 Screw-In Melt RTD Temperature Probe for Plastics Processing

A Pt100 melt probe with flat or blade tip for extruders and moulding machines

The JUMO 902090 is a screw-in melt RTD temperature probe used to record melt temperature in the plastics processing industry. It covers -50 to +400 degC, with connection lines chosen for the ambient temperature along the cable. The probe tip is stainless steel with a thermowell and process thread made of stainless steel 1.4571, and a ceramic-insulated tip is also offered. Blade-shaped or flat tips are available so the measurement can be matched to the requirement, whether a deeper reach into the melt stream or a flush position is needed.

The measuring insert carries a Pt100 to DIN EN 60751, class B, in 2-wire circuit as standard, and 3-wire or 4-wire connection is optional. Four basic types exist: 902090/10 with connection cable, 902090/20 with a plug connector (LEMO device outlet ERA-2S), 902090/50 with cable and ceramic insulated tip and 902090/60 with LEMO plug and ceramic tip. Two process threads are offered: M18 x 1.5 and 1/2 inch x 20 UNF.

Technical specifications

Decoding the 902090 order code

The order code has twelve fields: basic type – temperature and cable – measuring insert – tolerance class – fitting length EL – tip shape – tip length L – tip material – process connection – cable end – cable length AL / extra codes. The datasheet example is 902090/10 – 402 – 1003 – 1 – 152 – 4 – 15 – 26 – 153 – 11 – 3000 / 000. Flat tips use tip length 0, whereas blade tips are specified at 5 to 25 mm. Cable end and length are omitted (00 and 0000) on the plug types.

The stocked configuration is a 902090/10 with metal-braided cable for 400 degC, one Pt100 in 3-wire circuit, 152 mm fitting length, blade tip of 10 mm, 1/2 inch x 20 UNF thread, ferrules and a 3 m cable. The LEMO plug types need a matching mating connector (data sheet 90.9726).

Installation in extruders and what to check

The 1/2 inch x 20 UNF and M18 x 1.5 threads correspond to standard melt-sensor ports found on extruder barrels, adaptor flanges and dies, so confirm the port thread and depth before ordering (general practice, not a datasheet statement). The probe should be torqued and sealed as specified by the machine builder, and the protruding tip length should suit the melt channel so that it senses the stream without disturbing flow excessively. Blade tips reach further into the melt, flat tips sit flush.

Choose the cable by ambient temperature next to the machine: metal braiding for up to 400 degC, PTFE for up to 260 degC. Fit an anti-kink spring or metal protection hose where the cable may be bent or abraded. Use a 3-wire or 4-wire connection when cable runs are long so lead resistance does not appear as a temperature error. Typical uses are injection moulding, extrusion lines, blow moulding and film plants, usually wired to a process controller with a Pt100 input.

Fitting lengths other than 152 mm are specified in plain text. Plug-type versions use a LEMO ERA-2S outlet at the end of the probe, so the cable is replaceable without removing the sensor from the barrel. Mating 2/4-pin connectors are listed in data sheet 90.9726. Ordering a coated tip (material code 39) requires an agreement with JUMO, since the coating is not a standard catalogue item.

Documents and quotation

The JUMO data sheet 90.2090 (dated 2009-08-24) can be downloaded below. Seven Star LLC supplies JUMO probes from Muscat; provide the thread, fitting length, tip shape, cable and connection so we can quote correctly. See https://omansevenstar.com/product-category/sensors-transmitters/temperature/ for other temperature sensors.