®
M o d e l N o . T D - 8 5 1 3
S a m p le D a t a
15
C. Heat Waves
In this graph the far thermistor lags the near
thermistor by 11.1 s. The wave speed is
30 mm/11.1 s = 2.7 mm/s.
The wavelength is 140 mm, about twice the
length of the bar.
Experiment #2: Angstrom’s Method
A. Aluminum
B. Brass
Wide brass bar:
Period (s)
A
c
A
f
∆
t
k
(W/m·K)
Average
k
(W/m·K)
30
0.671
0.206
5.38
165
172
0.673
0.214
5.22
174
0.673
0.219
5.28
176
40
0.912
0.341
6.21
171
166
0.909
0.339
6.28
169
0.903
0.330
6.51
159
50
1.09
0.449
7.5
157
160
1.09
0.441
7.6
152
1.12
0.471
7.05
171
Average
165
Period (s)
A
c
A
f
∆
t
k
(W/m·K)
Average
k
(W/m·K)
50
0.430
0.110
10.2
106
107
0.452
0.121
9.7
115
0.426
0.108
11.1
97
0.429
0.118
11.1
103
0.440
0.123
10.3
112
