How to calculate application-specific data storage on X2 data loggers?

All X2 data loggers include a 256 MB internal SD card. Internal processes account for ~56 MB, leaving roughly 200 MB for data storage. Most applications will have years of available storage; however, this primarily depends on the logging frequency and the number of collected parameters. Below is an example calculation to estimate the number of days/years that the X2 will have available storage for a specific project.

Available SD Card Storage (with estimated overhead)

• 256 MB – 56 MB = 200 MB (200,000,000 bytes for data storage)

 

Application-Specific Criteria

• Sensor Configuration
  • Number of parameters = 16
  • Log Interval (minutes) = 10

• Number of logs per day
  • 1440 minutes per day ÷ 10 minutes = 144 logs per day

• Bytes per log
  • 8 bytes per parameter per log * 16 parameters  = 128 bytes per log

 

Overall Data Usage

• Bytes per day
  • 128 bytes per log * 144 logs per day = 18,432 bytes per day

• Days of storage
  • 200,000,000 bytes ÷ 18,432 bytes per day = 10,850.69 days of storage

• Years of storage
  • 10850.69 days ÷ 365 days per year = 29.73 years of storage

 

Data Calculation Table

The table below displays the years of data storage based on extremely frequent log intervals and the number of parameters in the sensor configuration.

Years of Data Storage
	# of Parameters
Log Interval (minutes)		1	2	3	4	5	6	7	8	9	10
	20	2.38	4.76	7.13	9.51	11.89	14.27	16.65	19.03	21.40	23.78
	40	1.19	2.38	3.57	4.76	5.95	7.13	8.32	9.51	10.70	11.89
	60	0.79	1.59	2.38	3.17	3.96	4.76	5.55	6.34	7.13	7.93
	80	0.59	1.19	1.78	2.38	2.97	3.57	4.16	4.76	5.35	5.95
	100	0.48	0.95	1.43	1.90	2.38	2.85	3.33	3.81	4.28	4.76
	120	0.40	0.79	1.19	1.59	1.98	2.38	2.77	3.17	3.57	3.96
	140	0.34	0.68	1.02	1.36	1.70	2.04	2.38	2.72	3.06	3.40
	160	0.30	0.59	0.89	1.19	1.49	1.78	2.08	2.38	2.68	2.97
	180	0.26	0.53	0.79	1.06	1.32	1.59	1.85	2.11	2.38	2.64
	200	0.24	0.48	0.71	0.95	1.19	1.43	1.66	1.90	2.14	2.38