Prueba

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<iframe width="450" height="260" style="border: 1px solid #cccccc;" src="https://thingspeak.com/channels/365537/charts/2?bgcolor=%23ffffff&color=%23d62020&dynamic=true&results=60&type=line&update=15"></iframe>

<iframe width="450" height="260" style="border: 1px solid #cccccc;" src="https://thingspeak.com/channels/365537/charts/3?bgcolor=%23ffffff&color=%23d62020&dynamic=true&results=60&type=line&update=15"></iframe>