Q: Do guarded hotplates and thermal manikins measure the same things?
A: While manikins and hotplates use similar basic principles to determine heat loss and insulation values, they typically have different end goals. A hotplate is designed to provide accurate one-dimensional heat and moisture flow through a fabric sample to determine thermal and water vapor resistance. The goal is to accurately evaluate the material properties. On the other hand, manikins are used to evaluate garment ensembles or environmental conditions and measure its contribution to human thermal comfort. The geometry, fit, and multi-fabric layer effects of finished garments make it necessary to use an anatomical form for testing.

Q: What test standards do hotplates and manikins satisfy?
A: Among others, our thermal measurement systems will test to ASTM D1518, ASTM F1868, and ISO 11092 (hotplates); ASTM F1291, ASTM F1720, ENV 342, EN 511, and EN 31092 (manikins). Please contact us if your requirements are not shown here - we can most likely accommodate your needs.

Q: You offer several different thermal manikins. What different purposes are they used for, and how do I know which is right for my needs?
A: Our manikins are normally user-application driven, and are a response to customer needs from a variety of industries - textile, automotive, fire protection, and government/military research. While different models may share a particular form, each tends to be unique due to variation in zones, joints, sensor placement, and materials. Let us know what your needs are, and we will customize a manikin to those specifications.

Q: What is the difference between metal and plastic skin manikins, and what are the advantages of each?
A: Metal-skinned manikins tend to produce a more uniform surface temperature due to conductivity of the metal, and use point sensors for data collection. Their accuracy makes them best suited as high-end research tools. Plastic-skinned manikins were developed as a lower cost industry tool, and use distributed wire sensors for data collection. Both styles can be fitted with fabric sweating skins.

Q: Do I need a sweating manikin, or can I get the data I need with a dry manikin?
A: For evaluating insulation properties and garment functionality in cold environments, a dry manikin is the best choice. To calculate evaporative resistance and garment performance in hot environments requires a sweating manikin, or in certain circumstances, a dry manikin plus a sweating hotplate.

Q: How do MTNW's sweating systems work, and can they be used with any manikin?
A: For both fabric and metal sweating systems, fluid metering in each zone is controlled using computerized pumps and valves. Fluid spread is achieved via the wicking capabilities of the fabric skin layer or the porous metal skin layer, (depending on the manikin).

Q: What values or results can we get out from manikin sweating tests?
A: There are several relevant measures you can get from sweating tests. The most basic measure is the operating heat flux required to maintain a constant skin temperature. In dry tests, it represents the conductive/convective/radiative heat transfer. In sweating tests, it also includes evaporative heat losses. To isolate the evaporative component, our ThermDAC software will automatically subtract off the "dry insulation" or Rct value from a previous test, and calculate permeability index or Ret in real time. This is the most common method of use.

For more specialized test programs, our ThermDAC software includes two additional modes of operation. This system can follow a user-programmed sequence of setpoints and sweat-rates, in either a temperature control or heat flux control mode. This allows simulation of work/activity cycles to predict real-life usage. A simpler mode is available to identify the evaporation limit of footwear. The surface is controlled to a constant temperature, and the sweat rate is increased in an operator set step-wise manner. With each fluid flowrate increase, the additional evaporative cooling results in a higher heat flux from the surface to maintain temperature. Once the evaporation limit is reached, the heat flux no longer increases with fluid steps and the evaporation limit is identified.

Q: Can we supply special function anatomical shapes?
A: One of MTNW's specialties is accommodating customer requests for specific body regions or measuring zone divisions. If you have a unique application, we will be happy to evaluate the feasibility and cost.

Q: Does MTNW provide start-up and training of these products?
A: Yes, our engineers travel worldwide supporting our products. We can also offer start-up support and training via e-mail for installations where an on-site presence would be difficult to manage.

Q: Do we offer equipment rentals or have demonstration systems available?
A: All of our equipment is built to order, and we maintain no completed inventory of demonstration or rental systems. We do offer technology demonstrations at our Seattle office that can be valuable for new users in understanding how to apply this sophisticated instrumentation. In addition, because our customers are distributed around the world, we can often arrange a site visit at a customer facility to demonstrate equipment in operation.

Q: What personnel commitment is required to operate MTNW equipment?
A: Our instruments are designed to accommodate a wide range of testing needs. For simple production tests, a single part-time technician is all that would be required to set up and start the tests. Automatic data collection and test sequencing allows the system to run unattended, generating a datafile and a test report at completion. With additional staffing, expert users operating the system can perform very complex test sequences and data analysis to observe transient response characteristics.

Q: What laboratory facilities would be necessary to operate and support the equipment?
A: MTNW builds systems to be self-contained and require a minimum of support commitment. All equipment is best operated in an environmental chamber for stable and controlled ambient conditions. Sweating systems will require a distilled or de-ionized water source. We manufacture equipment to operate on whatever power source is available at the customer's facilities. Manikin installations require a larger environmental chamber, walking stands (if desired), and a place to change manikin clothing between tests.

Q: Do we provide environmental chambers?
A: MTNW has alliances with several major international manufacturers to supply temperature and humidity controlled chambers or walk-in rooms. Please contact us with your application information and we can provide a quotation.

Q: Do manikins need to be tethered to the computer during testing or can they communicate via a wireless connection?
A: Both options are available. Wireless functionality can be provided for any manikin model, but heating power demands can quickly consume battery power and thus limit the total testing time available.

Q: Can we supply manikins for uses other than thermal testing?
A: We have supplied systems for other industries by applying our manufacturing concepts to produce body forms not available from standard sources. We cannot cost effectively supply manikins for fashion or display purposes.

Q: How can I be sure a foot model will work with a variety of footwear - for example, while testing boots with long uppers without zippers or cords?
A: We construct our feet in two or three parts for ease of insertion into semi-rigid footwear. We have been able to easily fit the model into hunting boots, ski boots, and even rigid shell in-line skates.