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DOCUMENTATION PAGE
REPORT NUMBER
TR-2010-11
NRC REPORT NUMBER DATE
May 2010
REPORT SECURITY CLASSIFICATION
Unclassified
DISTRIBUTION
Unlimited
TITLE
THERMAL MANIKIN CALIBRATION METHOD
AUTHOR (S)
Mak, L.1, Kuczora, A.1, Farnworth B.2, Hackett, P.1, DuCharme, M.B.3
CORPORATE AUTHOR (S)/PERFORMING AGENCY (S)
1
National Research Council Canada, Institute for Ocean Technology
2
Helly Hansen Canada
3
Defence R&D Canada
PUBLICATION
SPONSORING AGENCY(S)
Transport Canada
IOT PROJECT NUMBER
2296
NRC FILE NUMBER KEY WORDS
Manikin, calibration, calorimeter, standard, stirring system, NEMO PAGES v, 19, App. A-B FIGS. 14 TABLES 3 SUMMARY
In 2007 the International Organization for Standardization (ISO) established ISO/TC 188/WG 14 Thermal Manikin Working Group to study the suitability of using thermal manikins for approval testing and to propose updated wording to include manikins in ISO 15027-3 Immersion Suit Test Method. To systematically conduct research to investigate human and manikin equivalence, it is necessary to first establish a common, traceable calibration for thermal manikins, so there is confidence that thermal manikins accurately report temperatures, heat loss and power, and that differences in results among thermal manikins and manikin-human correlation are understood, quantified and accounted. The goal of this project is to develop a thermal manikin calibration method. It addresses the accuracy and repeatability of thermal manikins to accurately report heat loss, power and temperature. Without such a traceable standard, manufacturers and researchers will dispute differences in results from various thermal manikins. For this purpose, National Research Council Canada, Institute for Ocean Technology (NRC-IOT) constructed a calorimeter laboratory to house a full body water calorimeter transferred from Defence R&D Canada (DRDC).
The design specifications of the calorimeter laboratory and water calorimeter are presented in this report. A submersible thermal manikin calibration method is proposed. The results show that the laboratory and the calorimeter meet all design specifications, specifically
1. The calorimeter stirring system was able to establish an isothermal condition within 10 minutes. 2. The stirring system does not generate more than 100 W of power over a 2-hour period.
5. Under tracking control mode, the environmental chamber was able to maintain the air
temperature at a fixed offset with respect to the water temperature in the calorimeter, which is specified by the user.
6. Using a 500W known heat source, it was demonstrated that the calorimeter could measure power accurate to within 1%.
Using the calorimeter, the NEMO thermal manikin calibration was validated. The results show that the power reported by NEMO thermal manikin agrees with the calorimeter measured power to within 1% in both constant temperature and constant heat flux modes.
ADDRESS National Research Council
Institute for Ocean Technology Arctic Avenue, P. O. Box 12093 St. John's, NL A1B 3T5
National Research Council Conseil national de recherches Canada Canada Institute for Ocean Institut des technologies
Technology océaniques
THERMAL MANIKIN CALIBRATION METHOD
TR-2010-11Mak, L.1, Kuczora, A.1, Farnworth B.2, Hackett, P.1, DuCharme, M.B.3
Executive Summary
In 2007 the International Organization for Standardization (ISO) established ISO/TC 188/WG 14 Thermal Manikin Working Group to study the suitability of using thermal manikins for approval testing and to propose updated wording to include manikins in ISO 15027-3 Immersion Suit Test Method.
To systematically conduct research to investigate human and manikin
equivalence, it is necessary to first establish a common, traceable calibration for thermal manikins, so there is confidence that thermal manikins accurately report temperatures, heat loss and power, and that differences in results among thermal manikins and manikin-human correlation are understood, quantified and
accounted.
The goal of this project is to develop a thermal manikin calibration method. It addresses the accuracy and repeatability of thermal manikins to accurately report heat loss, power and temperature. Without such a traceable standard,
manufacturers and researchers will dispute differences in results from various thermal manikins. For this purpose, National Research Council Canada, Institute for Ocean Technology (NRC-IOT) constructed a calorimeter laboratory to house a full body water calorimeter transferred from Defence R&D Canada (DRDC). The design specifications of the calorimeter laboratory and water calorimeter are presented in this report. A submersible thermal manikin calibration method is proposed. The results show that the laboratory and the calorimeter meet all design specifications, specifically
1. The calorimeter stirring system was able to establish an isothermal condition within 10 minutes.
2. The stirring system does not generate more than 100 W of power over a 2-hour period.
3. Dye tests provided a visual means to assess and confirmed the stirring system performance.
4. Under regular control mode, the environmental chamber was able to maintain a user specified setpoint temperature to within ±0.1°C.
5. Under tracking control mode, the environmental chamber was able to maintain the air temperature at a user specified offset with respect to the water temperature in the calorimeter.
6. Using a 500W known heat source, it was demonstrated that the calorimeter could measure power accurately to within 1%.
Using the calorimeter, the NEMO thermal manikin calibration was validated. The results show that the power reported by NEMO thermal manikin agrees with the calorimeter measured power to within 1% in both constant temperature and constant heat flux modes.
TABLE OF CONTENTS
Executive Summary ... iii
List of Tables ... v
List of Figures ... v
1.0 INTRODUCTION... 1
2.0 PROJECT OBJECTIVES ... 2
3.0 CALORIMETER LABORATORY AND EQUIPMENT DESIGN SPECIFICATIONS ... 2
4.0 CALORIMETER LABORATORY AND EQUIPMENT FUNCTIONALITY TESTS AND RESULTS... 6
4.1 Assess the Effectiveness of the Water Stirring System in Maintaining an Isothermal Environment with an Array of Temperature Probes...6
4.2 Assess the Effectiveness of the Water Stirring System using Dye for Visualization ...8
4.3 Verify the Proper Functioning of the Temperature Control in the Environmental Chamber ...9
4.4 Verify the Proper Functioning of the Calorimeter using a Known Heat Source...11
4.5 Verify the Calibration of a Thermal Manikin...12
4.5.1 Manikin ...12
4.5.2 Experiments to Verify the Calibration of the Thermal Manikin ...15
5.0 CONCLUSIONS...18
6.0 RECOMMENDATIONS ... 18
7.0 REFERENCES... 19
Appendix A: Proposed Thermal Manikin Calibration Procedure Appendix B: Specifics of the Known Heat Source
LIST OF TABLES
Table 1. Comparison of calorimeter measured and known heat source power ..11
Table 2. Comparison of calorimeter measured and reported manikin power in constant temperature mode ...15
Table 3. Comparison of calorimeter measured and reported manikin power in constant heat flux mode...16
LIST OF FIGURES Figure 1. Calorimeter laboratory environmental chamber ...2
Figure 2. Operator’s control room ...3
Figure 3. Preparation and storage area with air handling unit...3
Figure 4. Full body water calorimeter...4
Figure 5. Temperature profiling in the calorimeter using an array of thermal probes...6
Figure 6. Overnight stratification in water is eliminated once stirring system is turned on for 10 minutes. ...7
Figure 7. Experiment to assess the effectiveness of the stirring system by visualization ...8
Figure 8. Temperature time series of environmental chamber...9
Figure 9. Environmental chamber air temperature maintained at 2°C above the calorimeter water temperature ...10
Figure 10. NEMO 23-zone submersible thermal manikin...12
Figure 11. NEMO submersible thermal manikin zones ...13
Figure 12. NEMO Thermal Manikin Block Diagram ...14
Figure 13. Manikin test in constant temperature mode ...16
1.0 INTRODUCTION
There has been increased interest internationally to investigate the equivalency between thermal manikins and humans, with the objective to use thermal
manikins to assess the thermal properties of protective clothing. Currently,
Canadian Immersion Suit Systems standard (CGSB, 2005), Canadian Helicopter Passenger Transportation Suit Systems standard (CGSB, 1999), and
International Marine Organization standard (LSA, 2009) allow the use of thermal manikins for approval testing of immersion suits, anti-exposure suits and
helicopter passenger transportation suits.
However, there is still resistance in Europe to use thermal manikins for approval testing of immersion suits. In 2007 the International Organization for
Standardization (ISO) established ISO/TC 188/WG 14 Thermal Manikin Working Group to study the suitability of using thermal manikins for approval testing and to propose updated wording to include manikins in ISO 15027-3 Immersion Suit Test Method. Between 2007-2009, a round robin test involving six international laboratories was conducted. The differences in results observed were attributed to manikin calibration, environmental condition, test method and analysis
method. This project focuses on manikin calibration.
To systematically conduct research to investigate human and manikin
equivalence, it is necessary to first establish a common, traceable calibration for thermal manikins, so there is confidence that thermal manikins accurately report temperatures, heat loss and power, and that differences in results among thermal manikins and manikin-human correlation are understood, quantified and
accounted. Once the manikins are validated, research can be conducted to assess and quantify differences between humans and manikins due to test methods, calculations, suit leakage, fit of the suit, human variability etc. Using this approach, a recent test concluded that within the scatter due to fit, folds and wrinkles of closed cell foam immersion suits, the heat loss from two thermal manikins was a good representation of the heat loss from humans (Mak et al., 2010, DuCharme et al. 2010). The results show differences between manikins and humans (+/- 12%), between humans (+/- 13%), and between manikins (+/- 6%).
Currently, manufacturers and regulatory agencies view thermal manikins as potential cost effective and repeatable means to assess thermal protection. Thermal manikins can also be used to develop new performance standards for protective clothing and equipment, and to assess the performance of lifesaving appliances. For example, when it is not suitable to use human subjects in severe cold environment studies, thermal manikins in association with mathematical models are likely the only ethically acceptable way to predict the performance of Arctic gear and survival equipment. Therefore, the development of thermal manikin calibration standard will also greatly contribute to the knowledge base of Arctic Research.
2.0 PROJECT OBJECTIVES
The goal of this project is to develop a thermal manikin calibration method. It addresses the accuracy and repeatability of thermal manikins to accurately report heat loss, power and temperature. Without such a traceable standard,
manufacturers and researchers will dispute differences in results from various thermal manikins. It may be impossible to fully understand and quantify these differences without knowing the accuracy of the manikins. There may be a lack of confidence in research results obtained using only one thermal manikin. These would hinder international acceptance of manikins as a reliable performance evaluation tool.
3.0 CALORIMETER LABORATORY AND EQUIPMENT DESIGN SPECIFICATIONS
For the purpose of this project, National Research Council Canada, Institute for Ocean Technology (NRC-IOT) constructed a calorimeter laboratory (Figure 1 to 3) to house a full body water calorimeter (Figure 4) transferred from Defence R&D Canada (DRDC).
Figure 2. Operator’s control room
The entire laboratory (15.25 m x 5 m) comprises of an environmental chamber (6 m x 5 m), an operator’s control room (2 m x 5 m) and a preparation and
storage area (7.25 m x 5 m). The test area houses the full body water calorimeter with a capacity of 1200 litres (Figure 4). The air-handling unit is located in the preparation and storage area while the condensing unit is located in the basement of the building, so warm air from the condensing unit does not re-circulate into the environmental chamber.
The proposed “Submersible Thermal Manikin Calibration Procedure” is
presented in Appendix A. The design specifications of the water calorimeter and the environmental chamber are detailed in Appendix A, Section 3. The water calorimeter and the environmental chamber were designed and built to these specifications.
Figure 4. Full body water calorimeter
The key features of the water calorimeter and the environmental chamber are as follows:
1. The environmental chamber is well insulated and has an operational range of 5°C to 35°C.
2. The air temperature of the environmental chamber does not deviate more than ±0.1°C from setpoint temperature.
3. The environmental chamber has two modes of temperature control. a. Regular mode maintains a user specified setpoint temperature.
b. Tracking mode keeps the air temperature of environmental chamber at a fixed offset with respect to the water temperature in the calorimeter, which is specified by the user. With this mode, it prevents
condensation on the lid of the calorimeter and maintains a constant heat exchange between the calorimeter and the environmental chamber.
4. The environmental chamber is equipped with two air temperature sensors and two humidity sensors at the two ends of the calorimeter. The temperature sensors have an accuracy of ±0.1°C. The humidity sensors have an accuracy of ±3% between 0 and 90% relative humidity.
5. The environmental chamber has an air lock, so the air temperature does not change significantly when people enter or leave the chamber.
6. The water calorimeter is capable of assessing power to within 1 percent accuracy.
7. The water calorimeter has a capacity of 1200 litres and a full size thermal manikin can submerge fully in it.
8. The water calorimeter is well insulated to minimize the heat exchange between the water inside the calorimeter and the air in the environmental chamber.
9. The water calorimeter is equipped with a system to stir water, so there is no temperature stratification and the temperature of the water is uniform in the calorimeter throughout the experiment. It is also used to reduce the boundary layer around the thermal manikin. The stirring system does not generate more than 100 Watt of heat over 2-hours.
10. The water calorimeter is equipped with 10 thermal probes at different
locations to measure the water temperature. The probes have an accuracy of ±0.1°C.
4.0 CALORIMETER LABORATORY AND EQUIPMENT FUNCTIONALITY TESTS AND RESULTS
This section shows results of these tests used to verify the proper functioning of the calorimeter laboratory and equipment.
4.1 Assess the Effectiveness of the Water Stirring System in Maintaining an Isothermal Environment with an Array of Temperature Probes
In this experiment, temperature probes arranged in an array of 5 lengthwise by 3 crosswise by 4 (60 in total) were used to assess the effectiveness of the stirring system in establishing an isothermal environment in the calorimeter (see Figure 5).
Figure 5. Temperature profiling in the calorimeter using an array of thermal probes
Each probe has an accuracy of ±0.1°C. After the temperature probes were installed, the calorimeter was filled with water and left overnight to create stratification. In the morning, the stirring system was turned on. Figure 6 shows the stratification and within 10 minutes after the stirring system was turned on, the stratification disappeared and the calorimeter established an isothermal environment. The deviation between 9.3 and 9.5 °C was attributed to the fact that the temperature sensors were not individually calibrated. The experiment was then repeated with the manikin in the calorimeter and it was again able to establish an isothermal environment within 10 minutes after the stirring system was turned on.
Figure 6. Overnight stratification in water is eliminated once stirring system is turned on for 10 minutes.
4.2 Assess the Effectiveness of the Water Stirring System using Dye for Visualization
In this experiment, dark blue water-soluble clothing dye was released through a syringe at different locations in the calorimeter to visually examine the
effectiveness of the stirring system. At all locations, it was observed that the dye diluted quickly and disappeared within 1 or 2 seconds. The experiment was then repeated with the manikin in the calorimeter (see Figure 7). The visual
assessment confirmed that the stirring system was effective.
Figure 7. Experiment to assess the effectiveness of the stirring system by visualization
4.3 Verify the Proper Functioning of the Temperature Control in the Environmental Chamber
The purpose of this experiment was to assess the ability of the control system in a. maintaining a user specified setpoint temperature under regular control
mode; and
b. keeping the air temperature of environmental chamber at a fixed degree Celsius higher than the water temperature in the calorimeter, which is specified by the user, under tracking control mode.
The temperature time series recorded by one of the sensors is shown in Figure 8. It shows the achieved temperature over 22 hours was 11.43 ± 0.03 °C,
compared to setpoint temperature of 11.5 °C. The results demonstrated that the environmental chamber was able to maintain temperature better than the design specification of ±0.5°C.
Figure 8. Temperature time series of environmental chamber
Figure 9 shows the environmental chamber air temperature maintained at 2°C above the calorimeter water temperature during an experiment to verify the proper functioning of the calorimeter using a known heat source. The water temperature sensor for the environmental control system data is strapped to the mount for calorimeter tank thermistor #3. Thus, the data for thermistor #3 shown here should represent the actual control system temperature.
Figure 9. Environmental chamber air temperature maintained at 2°C above the calorimeter water temperature
4.4 Verify the Proper Functioning of the Calorimeter using a Known Heat Source
The purpose of this experiment is to verify that the calorimeter can measure power accurately. Prior to and after the experiment, only the stirring system was turned on, so the calorimeter can determine the power it generated, Wstirrer. The water calorimeter has a built-in heating element that acts as a heat source. Known power of 500 W was supplied to the heating element by applying a measured voltage to a measured resistance. Specifics of the known heat source are shown in Appendix B.
ce sis
Voltage Measured
Wknownheatsource
tan Re
)
( 2
=
During the experiment (Figure 9), the stirring system and the heat source were turned on. Wstirrer + heat source denotes the power measured by the calorimeter during the experiment. The heat source power measured by the calorimeter, Wheat source, can be obtained using the following formula
stirrer source heat stirrer source heat W W W = + − where time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W source heat source heat steel steel water water stirrer / ) ( × × + × × + × × = time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W source heat source heat steel steel water water source heat stirrer / ) ( × × + × × + × × = +
Wknown heat source was then compared to Wheat source. The results are shown in Table 1. It shows that the calorimeter was able to measure power to within 1% accuracy. It also shows that the stirring system does not generate more than 100 W of power over a 2-hours period.
Table 1. Comparison of calorimeter measured and known heat source power Pre Experiment Post Experiment Calorimeter Experiment Known
Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wheat source [W] Wheat source [W] Diff [%] 3519 10305 91.37 21301 30286 87.74 11436 19614 503.95 499.22 0.9 14813 16980 87.36 25589 31431 85.17 17823 24686 504.29 499.22 1.0
4.5 Verify the Calibration of a Thermal Manikin
4.5.1 Manikin
A Measurement Technology Northwest (Seattle, Washington, USA) NEMO 23-zone submersible thermal manikin was used in this study (Figure 10). Its stature represents a 50th percentile adult North American male, weighing 71 kg. The manikin shell is made of aluminum.
Figure 10. NEMO 23-zone submersible thermal manikin
The 23 independently heated thermal zones are shown in Figure 11. Each thermal zone is equipped with heaters to generate uniform heating of the aluminum shell and two precision thermistors to measure skin temperature.
Figure 11. NEMO submersible thermal manikin zones
The main components of the thermal manikin are shown in Figure 12 and include:
• Heaters, sensors and internal controllers for regulation and monitoring • Power supply enclosure which includes the heater power supply, ground
isolation meter, serial data converter module, master zone controller, and an air pressure regulator.
• Ambient sensors (2 temperature, 1 relative humidity and 1 wind speed) • Interconnect cabling and air pressure supply hose
Figure 12. NEMO Thermal Manikin Block Diagram
The NEMO thermal manikin operates on 60Hz AC electrical power, 200-250 VAC with a maximum current of 20 Amps.
The ThermDAC control software is a 32-bit Windows based program that controls, records and displays real-time zone information numerically and graphically. Each thermal zone is individually controlled using either a temperature control, constant heat flux or comfort equation output.
ThermDAC is a fully automated data acquisition and control program. It has two independent methods of data logging. Full Data logging provides a complete data set of the entire run, at user selectable intervals. Steady State logging will write steady state average values to the file once the system has stabilized. These logging methods can be used individually or together. ThermDAC also includes an automatic steady state detection, which can initiate data logging.
Tests generate comma delimited (*.CSV) data files suitable for direct importing into Excel or any other compatible spreadsheet program. The data file contains a header with the data file name, test date, comments entered at test start,
setpoint, and logging interval. The data consists of a time stamp, followed by, in order, all zone temperatures, all zone heat fluxes, area weighted average
temperature, area weighted heat flux, area weighted thermal resistance, ambient temperature, and relative humidity.
4.5.2 Experiments to Verify the Calibration of the Thermal Manikin
In these experiments, the objective is to validate the proper functioning of the thermal manikin in constant temperature and constant heat flux modes. Prior to and after each experiment, only the stirring system was turned on, so the calorimeter can determine the power it generated, Wstirrer.
During the experiment, the stirring system and the manikin were turned on. Wstirrer + manikin denotes the power measured by the calorimeter during the experiment. The manikin power measured by the calorimeter, Wmanikin, can be obtained using the following formula
stirrer manikin stirrer manikin W W W = + − where time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W manikin manikin steel steel water water stirrer / ) ( × × + × × + × × = time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W manikin manikin steel steel water water manikin stirrer / ) ( × × + × × + × × = +
The reported power from the manikin, Wmanikin mfg, was then compared to the power measured using the calorimeter, Wmanikin.
The constant temperature mode results are shown in Table 2. It shows that the manikin agrees with the calorimeter to within 1%. The data reported by the thermal manikin were also examined to ensure that all manikin zones reached and maintained the specified setpoint temperature.
Figure 13 shows a typical constant temperature experiment. When analyzing the manikin data in constant temperature mode, it is important to ensure that all the energy generated by the manikin was transferred to the water, by ensuring that the manikin skin temperature is the same as the water temperature after an experiment.
Table 2. Comparison of calorimeter measured and reported manikin power in constant temperature mode
Pre Experiment Post Experiment Calorimeter Experiment Known Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wmanikin [W] Wmanikin mfg [W] Diff [%] 42259 45096 79.78 59923 63649 77.66 45244 58215 1439.72 1426.35 0.9 35720 38365 86.86 53194 55839 84.89 38550 51604 1520.31 1508.23 0.8 33654 36024 84.15 52089 54174 75.63 36613 51804 1342.42 1337.93 0.3
Figure 13. Manikin test in constant temperature mode
The constant heat flux mode results are shown in Table 3. It shows that the manikin agrees with the calorimeter to within 1%. The data reported by the thermal manikin were also examined to ensure that all manikin zones reached and maintained the specified heat flux. Figure 14 shows a typical constant heat flux experiment.
Table 3. Comparison of calorimeter measured and reported manikin power in constant heat flux mode
Pre Experiment Post Experiment Calorimeter Experiment Known Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wstirrer [W] Tstart [s] Tend [s] Wmanikin [W] Wmanikin [W] Diff [%] 34288 36218 81.87 42107 44132 82.01 36881 42056 218.59 216.23 1.1 47333 49073 85.19 56383 58762 88.24 49506 56052 380.88 381.57 -0.2 31621 33961 84.34 39564 41038 87.66 34561 39106 234.50 235.71 -0.5 44994 46618 90.43 52761 54235 81.47 47004 52108 513.97 509.60 0.8
5.0 CONCLUSIONS
A calorimeter laboratory and a full body water calorimeter were designed to validate the calibration of thermal manikins. The results show that the laboratory and the calorimeter meet all design specifications, specifically
1. The calorimeter stirring system was able to establish an isothermal condition within 10 minutes.
2. The stirring system generates less than 100 W of power.
3. Dye tests provided a visual means to assess and confirmed the stirring system performance.
4. Under regular control mode, the environmental chamber was able to maintain a user specified setpoint temperature to within ±0.1°C. 5. Under tracking control mode, the environmental chamber was able to
maintain the air temperature at a fixed offset with respect to the water temperature in the calorimeter, which is specified by the user.
6. Using a 500W known heat source, it was demonstrated that the calorimeter could measure power accurately to within 1%.
Using the calorimeter, the NEMO thermal manikin calibration was validated. The results show that the power reported by NEMO thermal manikin agrees with the calorimeter measured power to within 1% in both constant temperature and constant heat flux modes.
6.0 RECOMMENDATIONS
It is recommended that:
1. A thermal manikin calibration standard be developed by International Organization of Standardization (ISO), so that all thermal manikins can be calibrated to that traceable standard. This will enable cross-comparison of thermal manikin results with confidence. A proposed submersible thermal manikin calibration method is in Appendix A.
2. An air calorimeter be developed to validate the calibration of thermal manikins that are not submersible.
3. Further research be conducted to facilitate the cross-comparison of manikin, identifying, accounting for and quantifying the various sources of errors due to calibration, experimental conditions, and test and analysis methods.
7.0 REFERENCES
CGSB (1999), “Helicopter Passenger Transportation Suit Systems”, Canadian General Standards Board, CAN/CGSB-65.17-1999, Ottawa, Canada.
CGSB (2005), “Immersion Suit Systems”, Canadian General Standards Board, CAN/CGSB-65.16-2005, Ottawa, Canada.
DuCharme, M.B. et al. (2010), “A Comparison of Heat Loss Measurements on Manikins and Humans Wearing Dry Immersion Suits”, Abstract submitted to 8th International Meeting for Manikins and Modeling, August 22-26, 2010, Victoria, BC, Canada.
LSA (2009), “International Life-Saving Appliance Code”, 1997 edition and 2009 edition.
ISO (2002), “Immersion Suits – Part 3: Test Methods”, International Organization for Standardization, 2002
Mak, L et al. (2010), “Thermal Protection Measurement of Immersion Suit Comparison of Two Manikins with Humans Pilot Study Report”, National
Research Council Canada, Institute for Ocean Technology, Report TR-2010-06, St. John’s, Canada.
Appendix A
SUBMERSIBLE THERMAL MANIKIN CALIBRATION PROCEDURE
1.0 Scope
This procedure covers the calibration of submersible thermal manikins using a full body water calorimeter. The manikin can operate in either constant
temperature or constant heat flux operating modes.
It is used to independently verify that (1) the power output of a submersible thermal manikin is accurate; and (2) the manikin control software reports the output power accurately. It can also be used to monitor that all zones are able to maintain the set point temperature or heat flux.
2.0 Definitions
2.1 Submersible thermal manikin
A submersible thermal manikin is one that can be fully submerged in water.
2.2 Constant temperature control mode
User specifies the set point skin temperature for each zone in this mode. 2.3 Constant heat flux control mode
User specifies the set point heat flux for each zone in this mode. 3.0 Design of Equipment and Specification
1. The water calorimeter should be able to assess power accurately to within 1 percent.
2. The water calorimeter should be large enough to allow full submergence of the thermal manikin. This water calorimeter should have a capacity of about 1200 liters of water.
3. The water calorimeter should be well insulated so as to minimize the heat exchange between the water inside the calorimeter and the air in the environmental chamber housing the calorimeter. The environmental chamber should be able to maintain air temperature close to the temperature of water inside the calorimeter.
4. The water calorimeter should keep the mass of water constant over the period of the test. To minimize evaporation, a lid should cover the water calorimeter and to avoid condensation the air temperature of the
environmental chamber should be set 2°C above the water temperature. 5. The water calorimeter should be equipped with a system to circulate or stir
the water, so there is no temperature stratification and the temperature of the water is uniform in the calorimeter throughout the experiment. It is also used to reduce the boundary layer around the thermal manikin. The
6. The water calorimeter should be equipped with multiple thermal probes (minimum 10) at different locations to measure the water temperature. The probes can also be used as a measure of temperature uniformity in the calorimeter. The probes should be able to measure temperature
accurately to within ±0.1°C.
7. It is important to know precisely the mass of materials and the mass of water inside the calorimeter. The mass of water in the calorimeter can be determined manually by measuring each bucket of water poured into it or automatically by using a high precision load balance under the
calorimeter. If a high precision load balance is used, it could also be used to assess the mass of evaporated water. The amount of water put into the calorimeter should be measured accurately to within 1 to 2 kg.
8. The environmental chamber should be equipped with diffusers, so as to minimize the localized effect of the draft.
9. The environmental chamber should be well insulated and be able to maintain set point temperature to within ± 0.5°C. Temperature and
humidity probes should be installed in the environmental chamber to verify the performance of the control system.
10. The environmental chamber should have an air lock, so the room
temperature would not be significantly affected when people enter or leave the chamber. During an experiment, people should avoid entering or leaving the chamber.
11. Temperature, humidity and load sensors should to be calibrated annually using a reference standard.
4.0 Test Procedures
4.1 Assess the Effectiveness of the Water Stirring System in Maintaining an Isothermal Environment with an Array of Temperature Probes
1. Insert an array of temperature probes in a grid (5 along the length; 3 across the width; 4 along the depth) inside the calorimeter.
2. Fill the calorimeter with water and let it sit overnight so water temperature stratifies.
3. In the next day, monitor the temperature probes to confirm water temperature stratification.
4. Start the data acquisition system.
5. Start the stirring system. Run for 40 minutes. 6. Stop the data acquisition system.
7. Examine the data collected. If the water is properly stirred, the water temperature stratification should be eliminated within 10-15 minutes. 8. Repeat the procedure with the manikin in the calorimeter to make sure
that the stirring system is as effective in maintaining an isothermal environment.
4.2 Assess the Effectiveness of the Water Stirring System using Dye for Visualization
1. Install a syringe at one end of an extended tube and the needle at the other end. Support the extended tube with a metal rod so the needle can be easily moved to different locations in the calorimeter.
2. Put dark blue water-soluble clothing dye into the syringe. 3. Turn on the stirring system.
4. Move the needle to 60 locations in the calorimeter, in a three-dimensional grid, with 5 points along the length, 3 points along the width and 4 points along the depth of the calorimeter.
5. At each location, use the syringe to inject a small volume of dye into the water.
6. The dye should mix quickly and disappear if the stirring system is operating effectively. The turbulence on the water surface may make it
difficult to observe the mixing below the surface. A goggles can be place on the water surface and the experimenter can see the mixing through the goggle.
7. Repeat the procedure with the manikin in the calorimeter to make sure that the stirring system is as effective.
4.3 Verify the Proper Functioning of the Temperature Control in the Environmental Chamber
1. Choose a set point air temperature for the environmental chamber that is close to the actual test condition.
2. Turn on the data acquisition system to acquire the chamber temperature. 3. Set the environmental chamber control to the set point temperature. 4. Run the chamber for at least 10 hours once the set point temperature is
reached.
5. Turn off the data acquisition system.
6. Analyze the temperature data to verify that the control system was able to maintain set point temperature to within ±0.5°C.
4.4 Verify the Proper Functioning of the Calorimeter using a Known Heat Source
1. Measure the mass of steel inside the water calorimeter (msteel). 2. Measure the mass of water inside the water calorimeter (mwater). 3. Record the heat capacity of steel (csteel)
4. Record the heat capacity of water (cwater). 5. Set up a known heat source, such that
Power = Measured Voltage2 / Measured Resistance
6. Immerse the known heat source into the water and close the lid of the water calorimeter
7. Monitor the water temperature and set the environmental chamber temperature 2°C above the water temperature to prevent condensation.
8. Start the data acquisition system to acquire the temperatures of at least 10 distributed locations in the calorimeter.
9. Collect baseline condition for half hour 10. Start stirring system
11. Collect data for 2 hours with stirring system turned on only
12. Turn on the known heat source and the stirring system for 2 hours 13. Turn off known heat source
14. Collect data for another 2 hours with stirring system turned on only 15. Turn off stirring system
16. Turn off data acquisition system
4.5 Verify the Calibration of a Thermal Manikin
1. Measure the mass of steel inside the water calorimeter (msteel). 2. Measure the mass of water inside the water calorimeter (mwater). 3. Measure the mass of the thermal Manikin (mmanikin).
4. Record the heat capacity of steel (csteel) 5. Record the heat capacity of water (cwater).
6. Record the heat capacity of the Manikin (cmanikin).
7. Immerse the manikin into the water and close the lid of the water calorimeter
8. Set up the thermal manikin to run in constant temperature or constant heat flux mode. If the manikin is setup to run in constant temperature mode, the skin temperature should be set to a minimum of 5°C above water
temperature. If the manikin is setup to run in constant heat flux mode, the manikin power should be set to 300 W for low power, 700 W for
intermediate power and 1000 W for high power.
9. Monitor the water temperature and set the environmental chamber temperature 2°C above the water temperature to prevent condensation. 10. Start the data acquisition system to acquire the temperatures of at least 10
distributed locations in the calorimeter. 11. Collect baseline condition for half hour. 12. Start stirring system.
13. Collect data for 2 hours with stirring system turned on only. 14. Turn on the manikin and the stirring system for 2 hours. 15. Turn off the manikin
16. Collect data with only stirring system turned on at least until the manikin temperature is the same as the water temperature.
17. Data collection should be made for some time with stirring system turned on for the post-tare.
18. Turn off stirring system.
5.0 Data Analysis
5.1 Verify the Proper Functioning of the Calorimeter using a Known Heat Source
1. Average the temperature of water from thermal probes in the calorimeter. 2. Plot temperature of water versus time.
3. For the two sections with only the stirring system turned on, pre and post the experiment, compute the power input by the stirring system over a period of time, using the following formulae.
time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W source heat source heat steel steel water water stirrer / ) ( × × + × × + × × =
Average the pre- and post- stirrer power input.
4. For the section with heat source and stirring system turned on, compute the power of the heat source + stirring system by
time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W source heat source heat steel steel water water source heat stirrer / ) ( × × + × × + × × = +
5. Compute the power of heat source as
stirrer source heat stirrer source heat W W W = + −
6. Measure the power of heat source by
ce sis Voltage
Wknownheatsource /Re tan
2
=
7. Compare Wheat source with Wknown heat source 5.2 Verify the Calibration of a Thermal Manikin
1. Average the temperature of water from thermal probes in the calorimeter. 2. Plot temperature of water versus time.
3. For the two sections with only the stirring system turned on, pre and post the experiment, compute the power input by the stirring system over a period of time, using the following formulae.
time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W manikin manikin steel steel water water stirrer / ) ( × × + × × + × × =
4. For the section with manikin and stirring system turned on, compute the power of the manikin + stirring system by
time elapsed change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass change e temperatur capacity heat specific mass W manikin manikin steel steel water water manikin stirrer / ) ( × × + × × + × × = +
5. Compute the power of manikin as
stirrer manikin
stirrer
manikin W W
W = + −
6. Compare Wmanikin with the power reported by the manikin control software, Wmanikin mfg
7.0 Reporting
7.1 Assess the Effectiveness of the Water Stirring System in Maintaining an Isothermal Environment with an Array of Temperature Probes
Report on a graph with time on the x-axis and temperature on the y-axis,
responses of all temperature probes, showing the disappearance of temperature stratification within 15 minutes.
7.2 Assess the Effectiveness of the Water Stirring System using Dye for Visualization
Report whether that at each location the dye disappeared within 3 seconds. 7.3 Verify the Proper Functioning of the Temperature Control in the Environmental Chamber
Report the set point temperature, the temperature achieved and the standard deviation.
7.4 Verify the Proper Functioning of the Calorimeter using a Known Heat Source
Report the power computed using the calorimeter W heat source and the power measured W known heat source.
7.5 Verify the Calibration of a Thermal Manikin
Report the power computed using the calorimeter W manikin and the power report by the manikin W manikin mfg.
If the manikin operates in constant temperature mode, report the set point skin temperature and the steady state skin temperature of the manikin zones.
If the manikin operates in constant heat flux mode, report the set point heat flux and the steady state heat flux of the manikin zones.
Appendix B
