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Models PH – Power Heads
5.2
PULSED RF OPERATION THERMOCOUPLE HEADS
Figure 5-2 shows the regions of valid duty cycle and pulse power that apply to the thermal heads. As the duty
cycle decreases, the average power decreases for a given pulse power and the noise becomes a limitation.
Also, there is a pulse power overload limitation. No matter how short the duty cycle is, this overload
limitation applies. Lastly, the average power cannot be exceeded (there is some headroom between the
measurement limitation and the burnout level of the head.
Since the detection process in thermal head is heat, thermal heads can handle pulse powers that are two orders
of a magnitude larger than their maximum average power. This makes them ideal for this application. The
minimum pulse repetition frequency for the thermal heads is approximately 100 Hz.
Figure 5-2. Pulsed Accuracy for Thermocouple Heads
16
Rev C
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