September 4, 1998
To Whom It May Concern
Re: Attached Questionnaire
Dear Colleague:
Integrity Testing Laboratory Inc. of Toronto, Canada and LUMINOS
Computerized System Ltd. of Haifa, Israel are considering to design and
develop a number of instruments for measurements of thermal conductivity
and diffusivity of semitransparent materials, i.e. Thermal Conductivity
and Thermal Diffusivity Analyzers. These materials include glasses,
oxide ceramics, semiconductors, fluorides, chlorides, bromides,
tellurides, germanium, silicon, organic materials, highly porous heat
insulators, liquids, etc..
Presently, most of thermophysical properties' testing methods and
commercial instruments which are available on the market are based on
Fourier's equations which do not take into account the fact that
materials could be transparent for heat radiation.
The essential expansion of measurement possibilities is based on
another, radiative-conductive heat transfer theory (RCHT). The solution
of the inverse problem for these equations allows to calculate both the
radiative and the conductive components of effective (apparent) thermal
conductivity. The conductive component of the total thermal conductivity
is a property of the material at high temperatures and doesn't depend on
boundary conditions as the radiative component. The theory, design,
software and metrological analysis of the proposed equipment will have a
number of unique features allowing a comprehensive analysis of thermal
physical properties of semitransparent materials.
The methods to be used in the proposed instruments will be based on
accepted ASTM standard test method.
The final result of the measurements will be an effective (apparent)
thermal conductivity/diffusivity, which will be divided into the sum of
conductive and radiative components. For opaque materials or thick
specimens (optical thickness>>1) the measurement technique will give
the same results as standard methods conducted on presently available
commercial instruments that are based on Fourier's equations. Additional
information will be also available that will include the refractive
index and other characteristics of radiation attenuation. The conductive
component of thermal properties together with optical properties that
will be readily available from the suggested methodology will constitute
the basic information required to calculate the heat transfer in
semitransparent materials with any geometry and for any structures .
In order to assess the usefulness and marketability of such instruments,
we would greatly appreciate if you could take a few minutes to answer
the enclosed questionnaire. Feel free to add any additional comments
you think are useful. We would be glad to discuss any aspect of this
matter with you, should you be interested.
You can return the filled out questionnaire by e-mail, mail, or fax.
Your cooperation in this matter is mostly appreciated.
Very truly yours
Jacob Kleiman, Adj. Professor/UTIAS, President
_____________________________________________________________________________
QUESTIONNAIRE
1. What is your main area of expertise:
_____________________________________________________________________
2. What kind of semitransparent materials you apply or produce (delete
non-applicable items, please)?
glasses
crystalline oxides
semiconductors
thin coatings and films
highly porous materials
fluorides, chlorides, bromides
germanium, silicon
organic materials
other (please detail)
______________________________________________________________
2. What is your specific application of semitransparent materials
(delete non-applicable items, please)?
glass industry
electronics
air/space
glass fiber technology
highly porous materials
laser technology
metallurgy
other (specify, please)
_____________________________________________________________
3. What is usually the temperature range for your applications (delete
non-applicable items, please)?
300K
600K
1500K
2000K
over 2000K
4. Are you using thermal conductivity/diffusivity data (delete
non-applicable items, please)?
yes
no
5. What are your sources for thermal conductivity/diffusivity data
(delete non-applicable items, please)?
measurements
reference data
6. Do you need thermal properties data for semitransparent materials
(delete non-applicable items, please)?
yes
no
7. What error of thermal conductivity/diffusivity data is acceptable to
you (delete non-applicable, please)?
<10%
<30%
<100%
8. How do you characterize presently the thermal physical properties of
semitransparent materials (delete non-applicable items, please)?
Evaluate only the apparent, effective properties
Evaluate separate the conductive and the radiative thermal properties
other (specify, please)
_____________________________________________________________
9. How would you prefer to obtain the required data on effective thermal
conductivity/diffusivity of semitransparent materials (delete
non-applicable items, please)?
By purchasing an instrument and conducting the measurements yourself or
in your company
By measuring the required thermal properties in specialized test centers
or laboratories
Other __________________________________________________________________
10. Where do you use thermal physical properties data (delete
non-applicable items, please)?
Heat transfer calculation, design and optimization of apparatus
Choice and comparison of materials
Creation of data banks, preparing of reference data
Scientific research
Development of materials with predominant properties
Quality control,
Advertisement of materials for market
Other (specify, please)
_________________________________________________________
11. Where do you get additional information on optical properties of
semitransparent materials (delete non-applicable items, please).
measurement in your laboratory
measurment in specialized test centres
other (please, specify)
________________________________________________________
12. Do you believe that the proposed devices could or should be used for
modern application?
Yes (specify, please)
___________________________________________________________
________________________________________________________________________________
____
No (specify,
please)____________________________________________________________
________________________________________________________________________________
____
13. (optional) Name: _________________________________________
Profession: __________________________________________
Address: __________________________________________
________________________________________________________
Phone: __________________________________________________
Fax: ____________________________________________________
e-mail:________________________________________________
