European manikin standards and models to calculate thermal insulation

• ISO 9920 defines three insulation calculation methods: global, parallel and serial. It considers global method a general one that works in any situation, and parallel and serial could be used in specific cases. EN ISO 15831 is the basic manikin testing standard. It gives only two possibilities: parallel and serial. The specific requirements for equations’ use are not set as in ISO 9920, e.g. uniform heat loss or surface temperature. The parallel method is defined similarly to the global in ISO 9920. Thus, the calculation methods’ definitions in the standards differ. EN 342, EN 14058 and EN 13537 for testing cold protective clothing or equipment refer to the methods in EN ISO 15831. Calculation of insulation by any method or using the average insulation of both methods is allowed depending on the test results with reference calibration ensembles. However, several issues need to be considered when using serial method. EN 511 Protective gloves against cold gives its own equation assuming that the whole hand is just one zone. In the case of one zone the serial and the parallel model give the same result. More zones increase the insulation difference between the methods. With uniform surface temperature (required by EN ISO 15831) the parallel method provides the same insulation value with any number of zones while the serial method provides higher value with more zones compared to one zone. EN 342 (cold) and EN 14058 (cool) use the same measuring principles and the same calibration garments. In the case of evenly distributed insulation, the differences in serial and parallel methods are relatively small, and proportional. However, with more insulation layers overlapping in heavy cold protective ensembles the differences increase, and don’t follow the linear relationship any more. The calibration ensembles are selected to represent proper cold protective garments. Thus, if a garment piece does not represent a proper cold protective ensemble (faulty design, manufacturing error) the calibration does not have to be valid. Lately a study on insulation measurements with electrically heated vest was presented. The vest provided an additional 10 W totally to torso region, and turned results from serial method to impossible 83 clo. It may be argued that manikin test is not meant to measure clothing with auxiliary heating. However, what happens if components of an ensemble do employ smart textile technology? A standard should avoid allowing any unrealistic results. EN 13537 Requirements for sleeping bags utilizes the physiological model that has been developed assuming serial values to be correct. It works with properly manufactured sleeping bags. It would be a considerable work to replace the method, although, equally good models are available. Such a major change requires good will and participation from several labs including the ones outside Europe, too.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Produktionsteknik, arbetsvetenskap och ergonomi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Production Engineering, Human Work Science and Ergonomics (hsv//eng)

Keyword

predicted heat strain (PHS

protective clothing

high visibility (HV)

military (MIL) and firefighting (FIRE) clothing

Publication and Content Type

kon (subject category)

ref (subject category)