Hey @fourfathom, thanks, that helps a lot. I'm just starting to get some temperature ramp up data from mine, so it will be nice to have something to compare against.
I did a test run just now, where I had the micro turn the oven on, and ramp it all the way up to 250° C, then turn it off, all while spitting out the elapsed time and temperature every two seconds. I have the raw data, but haven't had time to graph it or do any math on it yet, to see how close to linear (or another shape) the curve is. I'll probably work on that this weekend, along with more testing.
This is with no additional insulation added, and with the outer cover off the case. Putting the cover back on and adding insulation would almost certainly give it a faster ramp up, but not sure if the extra insulation will prove necessary or not. Note: times are elapsed time since the oven was turned on, in milliseconds. So it takes about 112 seconds to reach 150° C, and about 290 seconds to reach 250° C.
Unfortunately I forgot the logging code in the branch after the oven is turned off, so I didn't get any data on the cool-down period. That will have to wait for this weekend.
MAX31856 thermocouple test
Thermocouple type: K Type
Turning OVEN on
6094,38.70
8095,38.74
10096,38.92
12097,39.48
14098,40.01
16099,40.76
18100,41.38
20101,42.32
22102,43.68
24103,44.92
26104,46.48
28105,48.45
30105,50.43
32107,52.88
34108,55.23
36109,56.72
38110,58.66
40110,60.77
42111,62.39
44113,64.33
46114,66.89
48115,69.15
50116,71.81
52117,74.73
54118,77.52
56119,80.40
58120,83.06
60121,85.89
62122,88.76
64122,91.73
66123,94.66
68124,97.58
70125,99.91
72126,102.75
74127,105.54
76128,108.15
78129,110.71
80130,113.55
82131,115.97
84132,118.54
86134,120.90
88135,123.23
90136,125.71
92137,128.09
94138,130.46
96139,133.08
98140,135.23
100141,137.30
102142,139.69
104143,142.20
106144,144.77
108145,147.09
110146,149.40
112147,151.77
114148,153.75
116149,155.80
118150,157.81
120151,160.20
122152,162.41
124153,164.43
126154,165.95
128155,167.55
130156,169.28
132157,171.14
134158,172.90
136159,174.64
138160,176.48
140161,178.12
142162,179.54
144163,180.73
146164,182.05
148166,183.74
150167,185.57
152168,187.45
154169,189.18
156170,190.81
158171,192.52
160172,194.12
162173,195.80
164174,196.96
166175,198.50
168176,199.80
170177,200.97
172178,201.88
174179,203.13
176180,204.23
178181,205.58
180182,206.45
182183,208.28
184184,209.75
186185,210.84
188186,212.09
190187,212.93
192188,214.21
194189,215.20
196190,215.73
198191,216.87
200192,218.16
202193,219.02
204194,220.09
206195,220.93
208196,221.87
210197,222.83
212199,223.62
214200,224.29
216201,224.83
218202,225.88
220203,226.89
222204,227.71
224205,229.41
226206,230.29
228207,230.56
230208,231.59
232209,232.15
234210,233.00
236211,233.88
238212,234.80
240213,235.68
242214,235.87
244215,236.47
246216,237.03
248217,237.43
250218,237.94
252219,238.37
254220,238.89
256221,239.70
258222,240.63
260223,241.34
262224,241.95
264225,242.40
266226,243.06
268227,243.29
270228,243.59
272229,244.30
274230,244.66
276231,244.95
278232,246.23
280233,247.23
282235,247.55
284236,247.79
286237,248.37
288238,249.31
290239,250.00
Turning OVEN off