What products are involved?All Rheonics sensors, transmitters and cables that have an IP rating. What is the purpose of this article?To explain the meaning of IP ratings, its digits and the protection levels Rheonics products have. |
1. IP Ratings Overview
IP (Ingress Protection or International Protection Mark) from IEC 60529 [1], rates the protection against intrusion of solids, accidental contact, dust, water and steam into mechanical housings and electrical enclosures.
The "K" in IP69K comes from ISO 20653 [2] (formerly DIN 40050-9), which adds a test with high-pressure, high-temperature water jets.
Categories are based on the use of two digits, which have specific meanings each, as follows.
Figure 1. IP rating digits meaning.
2. What Does Rheonics Offer?
Rheonics SRV and SRD probes are rated IP69K, SME-TR and SME-TRD transmitters IP66 / IP68 (1 m), and SME-DRM DIN-rail electronics IP20; standard cables are IP68, so the installed sensor reaches IP69K only with an IP69K cable.
Rheonics sensors are divided in three main parts, the sensor electronics, cable and probe. Each has a specific IP rating, as shown in Figure 2.
Figure 2. Rheonics sensor electronics, cable and probe IP protection rating.
Rheonics SR-sensor probes have an IP69K rating. Table 1 describes in more detail the protection ratings and Rheonics products.
Figure 3. SRV IP69K inline viscometer - other process connection variants available.
Figure 4. SRD IP69K inline density and viscosity probe - other process connection variants available.
Review all Rheonics sensor process connection variants here.
| Rheonics Devices | IP Rating | Protection level description | Notes / Considerations |
|---|---|---|---|
| SME-DRM sensor electronics for mounting on DIN rail, used in cabinets | IP20 [3], [4] | Protection against solid objects greater than 12.5 mm. No protection against water. | For indoor installations or to be installed in cabinets. |
| SME-TR, sensor electronics in transmitter housing SME-TRD, sensor electronics in transmitter enclosure with display | IP66 IP68 (1 m) | Total protection against intrusion of dust and solids. Protection against temporary flooding. | For indoors and outdoors installations. |
| SRV, inline viscometer (all variants) | IP69K | Sensor probe body is hermetically sealed and offers complete protection against intrusion of dust, solids and high pressure water or steam into the internal components. | Sensor cable and M12 connector with IP69K rating are needed for complete protection. |
| SRD, inline density and viscosity probe | IP69K | ||
| DVP, HPHT density and viscosity meter | IP69K | ||
| DVM, HPHT density and viscosity module | IP69K |
Table 1. Rheonics devices and IP ratings
Sensor cables with an M12 connector are connected to the probe back end. The IP protection of the cable varies between variants (standard, Ex, High-Temperature, etc.) and will influence the protection rating of the sensor once it is installed. Standard cables have an IP rating of IP68, but IP69K cables are also offered.
The connector IP ratings are IP68 for the standard (STD) and 90° cables, IP65 for the high-temperature (HT) cable, IP67 for the Ex cable and IP69K for the IP69K cable.
To have an IP69K sensor, both the probe and cable should be rated with such protection. |
Review all cable variants in this article: Rheonics sensor cable and connection variants.
3. References
- IEC, Degrees of Protection Provided by Enclosures (IP Code), IEC 60529:1989+AMD1:1999+AMD2:2013, 2013. [Online]. Available: https://webstore.iec.ch/publication/2452. [Accessed: Sep. 23, 2026].
- ISO, Road Vehicles: Degrees of Protection (IP Code): Protection of Electrical Equipment Against Foreign Objects, Water and Access, ISO 20653:2023, Aug. 2023. [Online]. Available: https://www.iso.org/standard/76116.html.
- Rheonics GmbH, Rheonics SRV Inline Viscometer Manual, DocID SRV-G1-OP-2606, Jun. 2026.
- Rheonics GmbH, Rheonics SRD Inline Density and Viscosity Meter Manual, DocID SRD-G1-OP-2606, Jun. 2026.