1. yes good point to do it after the test also.
3. signal conditioners
5. can you please go in o more detail onthis, im not so sure i fully understand this. i think i do but before i respond further please elaborate for me!
7 i thought good and hard about cooling and heating at the same time. however when you have them you have to account for them. heating is much easier to account for. cooling requires a bunch of extra precise flow and delta calculations. and for this system i was not willing to play the cooling game. however i did decide to use the "above ambient" method. this is actialy a " second version" of my setup after i did some testing and decided to go this rough of heating. the next step is to put the entire system is a double walled vacuum chamber of some kind...
#1. The reason you need before & after calibrations is because the outer environmental chamber may incur a temperature drift. To compensate for this, you will have before and after temperature measurements and can plot a linear drift slope that you will want to subtract out of the actual test data. This gets a little tricky, but you will want to incorporate it in your LOI and make sure any gurus that will review your process are good with how you mathematically compensate for environment drift. The purpose is pretty straightforward--you want to account for any heating/cooling within the test chamber by outside forces. The resulting "crunched" data should show a perfectly level plot depicting only heat added by way of the actual test. The control chamber should be a flat line from start to finish.
#3. Have a look at the four wire RTD signal conditioners here:http://www.dataq.com/data-acquisition/amplifiers/8b/
They are good to 3Hz, so sampling at 1Hz will be perfect. If you poke around I think you'll find DataQ makes a back-plane board with pluggable modules which makes things a bit tidier.
#5. What this boils down to is the method in which you go from raw data to final report data. For example, if you apply the leveling routine in step #1, you have effectively altered the test data. So you must show the algorithm applied, the time stamps and each data point before and after the application of the leveling routine. The leveling routine will use your before and after calibration points, so these too must be time stamped and accounted for.
#7. Above ambient should be fine especially if you apply a drift removal routine. For outdoor testing this is what I always did. For indoor laboratory testing I used overlapped heat/cool control. What you are shooting for is accountability. You will not be able to fully keep environmental thermal transients out of your test chamber, but you should be able to calculate exactly how much thermal energy is entering or exiting the internal test chamber. If you had absolutely perfect thermal insulation, then this would be a moot point. That's not the world we live in, so the next best thing we can do is to remove what we want to be a very linear drift. We don't want bumps and spikes from the environment entering into the test data. Instead we want a smooth predictable ramp of temperature change that can be easily calculated out of the final test data.
It's good to review the intent of the LOI. This document will state what you will are attempting to accomplish, how you will accomplish it and all the details needed for an exact replication. If you incur any deviations in your test procedure or test setup, you will need to add appendixes detailing why a change was made and exactly what the change was. When everything is said-and-done, your LOI will translate very smoothly into your final report. If done with precision, your LOI can simply be referenced in the final report. The final report will then become a summary stating your objectives and test results. In the end, all your hard work and planning should speak for itself.
Now that being said, I would highly recommend you find some certified PhDs fluent in this form of testing review and approve your LOI before you begin testing. Do expect to make changes. These guys live in this world and know what it takes to be successful. The testing I did went through Oregon Graduate Institute, Radian Corporation, Lockheed and a couple other academic institutions interested in our work. The final say was approved by the USEPA. You will encounter a lot of thrashing and head banging among these intellectual types so be prepared to have Klee draw the line when enough is enough. After all, Klee is funding this testing, so it's his call when he feels it's up to the caliber needed for publishing.