A typical system with 10 sensors reading every 5 minutes generates about 50 MB/month. You can use these rough number to scale to your system. For example if you have 50 sensors reading once per hour:
(50 sensors/10 sensors) * (5 minutes/60 minutes) * 50 MB/month = 21 MB/month
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scaled number of sensors scaled reading interval
(50 sensors/10 sensors) * (5 minutes/60 minutes) * 50 MB/month = 21 MB/month
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scaled number of sensors scaled reading interval
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