In  and  of the above expressions, the argument for the ber and bei functions as defined in Example 14 is  The amplitude of the centre-line temperature is
This relationship in numerical form is given in Table 3.
| Table 3: Attenuation Factor for a Thermocouple as a Function of the Dimensionless Frequency |
|
0 |
1 |
5 |
10 |
50 |
100 |
|
1.0 |
0.984 |
0.744 |
0.47 |
0.044 |
0.033 |
For  the attenuation is nearly  . For a copper shield (  m2 /s) a diameter of 20 mm gives a corresponding frequency as 60 Hz. The temperature sensed by the thermocouple drops further at higher forcing frequencies applied at the surface of the shield.
|
