JUMO 902190 Push-In RTD Temperature Probe with Bayonet Lock and Spring Pressure

A spring-loaded bayonet probe for measuring in drilled holes

The JUMO 902190 is a push-in RTD temperature probe with a bayonet lock, intended for measuring temperature in solids, on bearings and on moulding tools, for example in the plastics industry. The special shape of the measuring tip suits flat-bottom and cone-shaped bores. A pressure spring made of rust and acid resistant stainless steel (material reference 1.4310) acts as cable protector and holds the tip against the bottom of the hole with uniform pressure, which gives good heat transfer; JUMO notes the spring pressure is adjustable.

The probe is inserted and removed without tools. Rotating the bayonet lock alters the fitting length, and locks are available with 12, 15 and 16 mm diameters. The probe is made as a single or twin RTD, normally a Pt100 to EN 60751 class B in 2-wire circuit, with Pt500 or Pt1000 and 3-wire or 4-wire connection as alternatives. Three basic types differ in tip material and shape: stainless steel flat-bottom, ceramic 120 degree tip, and a further flat-bottom stainless version.

Technical specifications

Specifying a 902190: tip, cable, lock and stocked items

Order code: basic version – operating temperature and cable – measuring insert – tolerance class – sheath diameter – fitting length – cable end – cable length / extra codes. The example is 902190/10 – 397 – 1003 – 1 – 8 – 175 – 11 – 2500 / 000. Extra codes are 000 (none), 302 (bayonet lock 15 mm), 303 (bayonet lock 16 mm), 317 (shielded cable) and 880 (DNV approval, limited to a maximum fitting length of 400 mm and cable length of 10,000 mm). Code 880 is listed for two of the three basic types only.

The mating bayonet sockets are separate items described in data sheet 909750; the lock diameter chosen here must match the socket to be fitted.

Fitting into bores, tools and bearings

Drill a bore with a flat or conical bottom to match the tip, fit the bayonet socket, then push the probe in and turn the lock a quarter turn. The compression spring keeps contact pressure steady while the machine part expands and contracts, which keeps the reading from drifting when a clamp loosens. Because the fitting length can be changed by turning the bayonet lock, a single probe covers a range of bore depths within the printed limits (for example 20 to 175 mm on the long type).

The ceramic 120 degree tip of the /20 type suits conical bores. Choose the cable for the ambient temperature along its route, since PTFE and metal braiding withstand much higher temperatures than silicone, and select the shielded cable option in electrically noisy plants. Typical uses are injection moulds, extruder barrels, motor and gearbox bearings, press platens and heater blocks, where a solid body temperature, not a fluid temperature, is needed. For hot-runner or melt measurement a different JUMO probe type would normally be chosen.

Cable choice sets how far the probe can be installed from the controller and how hot the machine surface may be. Silicone cable handles -50 to +180 degC ambient, PTFE reaches -190 to +260 degC and metal braiding -50 to +350 degC. Cable ends can be bare, fitted with ferrules to DIN 46228, a 6.3 mm receptacle to DIN 46247 or a multipole connector, and a shielded cable is optional. Bayonet sockets in data sheet 909750 are welded or screwed into the machine body, so plan them before the probe is delivered and match the 12, 15 or 16 mm lock diameter to them.

Documents and quotation

The JUMO data sheet 902190 (2026-09-03) is attached for download. Seven Star LLC supplies JUMO probes from Muscat; please provide the fitting length, sheath diameter, cable material and length, and bayonet diameter so we can quote. See https://omansevenstar.com/product-category/sensors-transmitters/temperature/ for more temperature sensors.