1? a 
Sr Jon?) _ Ig (ur) ame 1+ £ log $) Q Jour) pr ae 
Ee es = 
Da Jy (a,b) Jy (ud) i. 
pe IAD) Dog) 
n= 1 kK, (u? b? + — 1h» 2 fey S\N oe 
Ky eee [65] 
es Tee) 14+ flog & 
yi pi eons CEA ates [66] 
a My (B, 5) 1+ log & 
Oy D,=1 [67] 
n= 
For the bare wire G, = P and a, is defined by Equation [45]. Then De becomes 
[68] 
4a? Ti (P - Q)? 
i 2 2 
2 P 
Kip (a, - p?) (« De + =) (or De + = 
Bs] ESS) 
RESPONSE GF A CONSTANT- TEMPERATURE COATED HOT WIRE 
TO A STEP-LIKE CHANGE IN CONVECTIVE COOLING 
If a constant-temperature hot wire is subjected to a step-like change in the rate of con- 
vective cooling, the wire response is given by a current change in the circuit. The problem 
from which 6, (7, fg) po (tr, t), and A/(¢) may be evaluated is obtained from Equations [15] 
and [16]. 
Jy (ur) 
Jo (u 5) 
Ob, 2 2 1 99, 
So Oar) asd sto 7 8e 
1 2 ( So2) 2 fs 
Pr OF or / y 
[69] 
K,@ (2) +P, (a,t) =PAT#* -[T(a)-T,]AP*=S 
15 
