Instructables
The following is my analysis of cooking a turkey. I will be measuring temperature and time for a 20 pound turkey cooked in a Rival brand roaster.
 
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Step 1: Instruments

TEMPRITE Digital Cooking Thermometer with Alarm
Resolution: .1 degrees
Temperature range of -40 to 450 degrees F
6 inch metal probe with silicone coated wire
"Slow" response time and low temperature range suggests this uses a thermistor

Rival Top Browning Roaster Oven
Capacity: 18qt
Possibly broken temperature knob. It feels as if no internal component is moving.

Step 2: Calibration

Whenever you take measurements, your instruments should be calibrated (if applicable). The probe of the TEMPRITE thermometer was submerged in ice water. Phase change (freezing/melting point) for water occurs at 32 degrees F. Therefore, the ice water should be approximately 32 degrees F.

5 Measurements were taken. Crushed ice was poured into a cup and then filled with water. Between each measurement, the water was poured off, the ice was topped off and the water refilled.

1: 32.4
2: 33.6
3: 31.5
4: 32.0
5: 32.2

Mean: 32.4 degrees F
Standard Deviation: 0.777
r squared: .13

For the purposes of the analysis, it is assumed that the instrument is accurate. Deviation from 32 degrees F can be attributed to minerals and other "imperfections" in the water in addition to human error etc. Horrible r squared value can be attributed to very low sample size (an ideal r square value is 1 or very very close to 1).


Normally, I would have also tested on boiling water. Unfortunately, my stove and oven at home is out of commission (and on thanksgiving too :( ). For some reason it won't hold oven temperature and will be replaced the Saturday after thanksgiving...


Below is a graph with the calibration data - if the r squared value was close to 1, the pink regression line would be very close to horizontal (zero slope).
Predictor1 year ago
Regarding your calibration in ice water, I don't know why you're calculating the r-squared of temperature measurements versus trial number. The standard deviation is the summary which shows how much your measurements "wander" from 32 F. Regardless, your freezing measurement wanders only a few degrees at most from the anticipated value, which I think is fine for this work.
dataphool7 years ago
Have you repeated this effort, possibly with a different size bird (hence different dimensions.) I find it curious, you have an obvious scientific bent, but your measurements are in fahrenheit rather than Celsius, or even Kelvin. Oddly enough, cooks and bakers in Canada and presumably in the UK still use fahrenheit; even tho' magazines with recipes talk about 300C (450F) pretending their readers are up-to-date and the minority have to use the conversion. Friends of mine tell me that German carpenters still measure nails in inches, and housewives still by a pound of butter; and Napoleon convert Germany 200 years ago.
trebuchet03 (author)  dataphool7 years ago
Nope, there hasn't been an occasion for turkey (or whole bird for that matter) :/ It's a pity though :P


I displayed the measurements in Fahrenheit because I figured most of the target audience (Instructables readers -- mostly from USA) would feel more comfortable with it. I however, have no problems with either scale (that is, you tell me it's 17 degrees outside and I'll know to wear a sweater) :P


As for scientific purposes... the scale you choose is of no consequence -- conversions can be made quite easily and quickly.... Hell, if I wanted to use Rankine (absolute scale of Fahrenheit -- like Kelvin) it would still have the same heat content :P As long as you stay consistent, the mars lander will be fine :D


As for your citations of usage of the imperial system -- it just goes to show that tradition is deeply rooted in every society. It doesn't make it wrong or anything either :D That's also very interesting; I had no idea.


Last bit.... To be honest, I prefer Meters-Kilograms-Seconds over Feet-Slugs-Seconds ;) It's just so easy to convert between minor units and when I calculate my mass, I'm happier saying 58Kg over 4slug :P
Automate the data logging, you could set a webcam to capture the temp every x minutes, convert with ocr and paste into a spreadsheet. BTW Considering the average quality of your instructables, I was expecting the calibration to be done with a homebuilt triple point cell.
trebuchet03 (author)  Tool Using Animal8 years ago
I never even thought of making (or using) a tpc. Considering I have only heard of and never physically seen one, that should be an interesting project. Although, I think you're supposed to use some sort of special water. I love how these projects breed my next project with these suggestions :P Next year, I'll look to capture and OCR :)
canida8 years ago
You probably put your probe too close to a bone. They get much warmer and can really throw off your measurements.
0.775volts8 years ago
regarding your theromocouple:
neverimd, i'll post this in your thermocouple instructable
http://www.instructables.com/id/ENVQPD6YV1EUR4U2XC/