Thermal burden as an essential aspect of CBRN protective clothing Nowadays, many military missions are performed in areas with a neutral to warm climate. In such areas not only the protective efficacy of CBRN-protective clothing is important, but also the thermal burden to the user. A high thermal burden will reduce operational efficiency significantly. Using human volunteers to actually measure the thermal burden is a valid but expensive and time-consuming approach. A more cost-effective and rapid approach is to be preferred. Tool to predict thermal burden The numerical model THERMPro was developed for ProQares by TNO to predict the thermal burden of a CBRN clothing system of interest. For predetermined activities of average persons in the standard (NATO) climates the time course of the core temperature and the sweat production is calculated. From the data generated by the model ‘comparative safe working times’ can be calculated for the various environmental conditions, relative to a reference CBRN-protective clothing system. These simulations are not intended to determine the absolute safe working time of a certain system since this parameter is only used for comparison its thermal burden with other (reference) systems. The approach is depicted below. THERMPro: Predicting the thermal burden of CBRN protective clothing Awareness is growing that thermal burden is an essential aspect of CBRN-protective clothing. Traditionally, this aspect is studied in trials with volunteers, which is both time-consuming and expensive. ProQares offers a modeling tool, called THERMPro, to predict the thermal burden of a clothing system of interest in comparison to a reference system, which is a cost effective and rapid approach. Proof of reliability. Fixed conditions Activity Climate Person Comparative Safe- working-time Combining parameters CBRN clothing specific parameters SCOPE Light [numerical model] Fabric thickness Fabric weight Core temperature Sweat production Air permeability Heat resistance Evaporative resistance
Transcript
Thermal burden as an essential aspect of CBRN protective clothing Nowadays, many military missions are performed in areas with a neutral to warm climate. In such areas not only the protective efficacy of CBRN-protective clothing is important, but also the thermal burden to the user. A high thermal burden will reduce operational efficiency significantly. Using human volunteers to actually measure the thermal burden is a valid but expensive and time-consuming approach. A more cost-effective and rapid approach is to be preferred.
Tool to predict thermal burdenThe numerical model THERMPro was developed for ProQares by TNO to predict the thermal burden of a CBRN clothing system of interest. For predetermined activities of average
persons in the standard (NATO) climates the time course of the core temperature and the sweat production is calculated. From the data generated by the model ‘comparative safe working times’ can be calculated for the various environmental conditions, relative to a reference CBRN-protective clothing system.
These simulations are not intended to determine the absolute safe working time of a certain system since this parameter is only used for comparison its thermal burden with other (reference) systems.
The approach is depicted below.
THERMPro: Predicting the thermal burden of CBRN protective clothing
Awareness is growing that thermal burden is an essential aspect of CBRN-protective clothing. Traditionally, this aspect is studied in trials with volunteers, which is both time-consuming and expensive. ProQares offers a modeling tool, called THERMPro, to predict the thermal burden of a clothing system of interest in comparison to a reference system, which is a cost effective and rapid approach.
Air permeabilityHeat resistanceEvaporative resistance
Which input is needed?The model requires various CBRN-specific parameters, such as weight and thickness of the fabric, its air permeability, as well as its heat and evaporative resistance.
Which output is generated?The tool will generate graphs showing the thermal burden for all relevant combinations of environmental air temperature and relative humidity, see Figures below. These graphs visualize intuitively how suitable a clothing system is for the various climates discerned by NATO.
What are the benefits of this approach?This approach provides a rapid and cost-effective insight into the anticipated thermal burden of CBRN-protective clothing systems compared to a reference system. The predictions of the tool can be used to aid the design of volunteer trials and can be validated by comparison with results obtained in volunteer trials. This is a joint effort of TNO and ProQares for which TNO provides scientific support for the tool to ProQares, and maintains the tool.
Many professionals worldwide trust their lives to protective equipment against chemical and biological hazards. Proqares is an internationally leading provider of testing, evaluation and certification services targeted at such personal protective equipment. Proqares has an extensive track record in testing CBRN (Chemical, Biological, Radiological and Nuclear) protection devices for military personnel and first responders; commonly tested devices include respirators, CBRN protective clothing, boots and gloves. Also, Proqares provides a range of services targeted at personal protective equipment for the Chemical, Medical en Pharmaceutical industry. Within its High-Tox facility, Proqares is capable of working with the most toxic chemicals known to man, providing the fastest and most reliable results in the industry. Any test specified in all commonly cited standards is offered - national and international standards, military and civil. Integrity, flexibility, speed and reliability are core values of Proqares and its employees.
Proof of reliability.
From the graph, tables are derived specifying the safe comparative working times for the clothing system of interest in the various climate zones for the selected work load. An example is shown below.
