nomad HB3289-01, Users Handbooks

Page: 51 / 68

The following equations let the user calculate the record capacity and
the store duration.
These equations should be used only as a guideline as the logging interval may
change during operation, especially if the “fast mode” option has been enabled
in the alarms.
Some example internal result capacities are shown in Table 1.
Table 1: Internal Store Capacity (512 kB)
Number of
Channels
Logging Interval
(mins)
Record Capacity Storage Capacity
1 1 47662 33 days
1 10 47662 33 days
1 60 47662 5.4 years
7 1 14979 10 days
7 10 14979 104 days
7 60 14979 1.7 years
7.3.2 External Capacity
When logging to external media such as CompactFlash™ cards, the store is
updated with data being added to the card until it becomes full. Logging will
then stop until the card has been replaced with an empty one.
The following equations let the user calculate the record capacity and
the store duration for external media.
Again, these equations should be used only as a guideline, for the same reasons
as given for the internal store and also because of the approximation that only
95% of the card’s capacity is available for actual data storage. Some example
CompactFlash result capacities are given in Table 2.
Table 2: External Store Capacity (16 MB)
Number of
Channels
Logging Interval
(mins)
Record Capacity Storage Capacity
1 1 1448941 2.7 years
1 10 1448941 27 years
1 60 1448941 165 years
7 1 455381 316 days
7 10 455381 8.6 years
7 60 455381 51 years
524288
7 4
+
=
( )
Re
Channels x
cord Capacity
Re cord Capacity x Logging Interval Store Duration
=
( . )
( )
Re
Capacity in MB x x
Channels x
cord Capacity
1048576 0 95
7 4
+
=
Re cord Capacity x Logging Interval Store Duration
=
Sensus Data Logger
Page 51 of 68
NOMAD Portable Weather Station
Users Handbook