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HIGH POWER MEASUREMENT
By Calorimetric method
About the method..
• Measured by calorimeter
• Microwave Heat energy
• Heat absorbed by fluid then measuring the
temperature rise
Types
• Direct method:
Heat can be observed by rise in the
dissipating medium
• Indirect method:
Heat transferred to other medium then
measured.
Type of measuring meter
»Static calorimeter
»Circulating calorimeter
• Static calorimeter:
• it consist of 50𝞨co-axial cable, filled
with dielectric load whose hysteresis loss is
high.
• Average power input is:
• P= watts
• m = mass of the thermometric medium in gms
• = its specific heat in cal/gms
• T= temperature rise in degree celsius
• T= time in sec.
**
Circulating calorimeters
P= 4.187 v d Cp T watts
Limitation
• Thermal inertia caused by lag between
application of microwave and parameter
readings.
• Thermal inertia- the degree of slowness with which the temperature of a body approaches that of its surroundings