xxsteven69xx Posted January 13, 2016 Author Report Share Posted January 13, 2016 I have run the case analyzer 4 times on the VT200 and have gotten drastically different numbers each time. The only time my room temp is accurate is when first powered on from stand-by, when the board is room temp. My question would be what are the correct conditions for running case analyzer, and what is a tolerable variance for calculated room temp and actual temp? First, I would assume stable room temperature and no air flow. What are the tolerances for this test? Short of putting my mod in an insulated box with a thermocouple. Or is this just having different thermal properties in a given environment at any given time? I'm starting to see why manufactures are not filling in their default settings for at least the case. Is 5°F to 10°f ± acceptable? Is estimated room temperature just there to get a ball park number for temp control or is something like 1ºf needed. obviously the more accurate is better. Am i just overestimating the needed accuracy and this is just splitting hairs? I understand this might be the best Evolv can do with one temperature sensor on the board and that the VT200 thermal properties might fluctuate very widely in different conditions and mod to mod. I would imagine maybe a plastic or wooden case might have more stable, more predictable, variables. Or maybe the other way around, would heat sinking the board to the case help or hurt this?Sorry, I know this post is long and not the best format. I just want to understand the best I can, and have the best device I can.PS What is F/A? Fahrenheit per area,amp charge, or something else? Link to comment Share on other sites More sharing options...
Bayk1ll Posted January 16, 2016 Report Share Posted January 16, 2016 the "room" temperature should actually be the temp of the area inside the case as it doesnt have any way of detecting temperture outside the case unless it is open or really well ventilated also test the reader by having the case open and blowing on the chip should lower the "room" temp by a degree or 2... hope this helps Link to comment Share on other sites More sharing options...
xxsteven69xx Posted January 17, 2016 Author Report Share Posted January 17, 2016 While I initially thought the same thing, after some experiments and reading the escribe manual about the case analyzer. The statics in the thermal section in escribe describe how the board temp is effected by the thermal properties of the case. Yes, blowing on the board would result in the board computing that as room temp going down, because it thinks that if the board temp is being cooled faster than whats expected for the estimated room temp, ergo the room temp must be lower. This is why getting an accurate measurement on the case analyzer is important for the board to calculate an accurate estimate. Link to comment Share on other sites More sharing options...
retird Posted January 17, 2016 Report Share Posted January 17, 2016 Process I use:Set device in the room in the location of where you will be while running mod analyzer and leave overnight. Do not touch or use. Have the usb cable attached to the device but not the computer.Set a digital thermometer next to the device and leave overnight also. Leaving overnight should allow the internal temperature of the device to be the same as the room temperature.Next day:Have EScribe up and running and then plug in the usb cable to the computer. No need to touch the device.Run the mod analyzer immediately and enter the room temperature as seen on the digital thermometer. Analyzer will run until finished... Link to comment Share on other sites More sharing options...
VapingBad Posted January 17, 2016 Report Share Posted January 17, 2016 IIRC the first two values the time constants are not as important as the delta A and degree F/A. I asked John why my results were different and he just commented on those to being close. Link to comment Share on other sites More sharing options...
xxsteven69xx Posted January 17, 2016 Author Report Share Posted January 17, 2016 Thank you for the info guys. Link to comment Share on other sites More sharing options...
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