SIST EN 61152:1998

Overview

EN 61152:1994 (identical to IEC 61152:1992, adopted nationally as SIST EN 61152:1998) defines the dimensional requirements for metal-sheathed thermometer elements used in industrial temperature measurement. The standard specifies the nominal diameters for metal-sheathed elements and establishes tolerances on those diameters, plus straightness/shape classes and a straightness gauge to ensure fit into thermometer pockets or wells.

Key SEO keywords: metal-sheathed thermometer elements, EN 61152, IEC 61152, thermometer sheath dimensions, thermometer element diameters, diameter tolerances, straightness gauge.

Key Topics

• Nominal diameters: The standard lists a set of nominal sheath diameters (D). Typical available sizes given include 1.0, 1.5, 2.0, 3.0, 4.5, 6.0, 8.0, 9.5, 12, 14, 15, 17.5, 22.2 and 24 mm.
• Diameter tolerances: EN 61152 specifies tolerances (d) on the sheath diameters to ensure interchangeability and fit with pockets or wells. (Exact tolerance values are provided in the standard’s Table 1.)
• Straightness and shape classes: Elements and pockets are categorized into internal/external shape classes (illustrated as types A, B and C). The standard defines how straightness is verified using a straightness gauge for each nominal diameter.
• Length/fit requirements:
  • Type A elements must meet diameter tolerances over a length of 10 × D from the tip and must pass the straightness gauge over the length that will be inserted into the well.
  • Type B elements require tolerance compliance over the tip section or 10 × D (whichever is less) and must pass the gauge over that same length.
  • Type C elements must meet tolerances and pass the gauge over the entire larger-diameter portion.
• Performance note: For faster thermal response, closer diameter tolerances than those listed may be required and should be agreed between manufacturer and user.

Applications

• Ensures interchangeability of sensor elements and compatibility with standardized thermometer pockets, wells and mounts.
• Used by thermocouple/RTD manufacturers, instrument designers, process engineers, procurement/specification writers, quality control and calibration laboratories.
• Common in industrial process measurement, HVAC, petrochemical, power generation and laboratory environments where reliable fit and thermal response are important.

Related Standards

• IEC 61152:1992 - original international text on which EN 61152:1994 is based.
• SIST EN 61152:1998 - national (Slovenian) adoption of EN 61152.

For precise tolerance numbers, figures for shapes and the straightness gauge dimensions consult the full EN/IEC standard document (Table 1 and accompanying figures).