Delta-T Devices AP4, User Manual

Page: 41 / 64

HOW TO CALCULATE AVAILABLE MEMORY
Page 41
HOW TO CALCULATE AVAILABLE
MEMORY
1 reading uses 20 bytes
Each note uses 0 - 30 characters = 0 - 30 bytes.
Each group of readings uses an additional 44 bytes (independent of the length of the
group name).
Memory size = 32000 bytes
Number of readings
=
(
𝑎×3200
100
)−(𝑏 ×44)
20 + 𝑐
where a = % memory left
b = number of groups of data
= number of experimental plots, for instance
c = average length of annotation (to 30 characters)
Example (1)
Given: No notes, 1 group
Maximum number of readings =
(32000 – 44)
20
= 1597 readings
- == = 1 reading every 18 seconds for 8 hours
-
Example (2)
Given: 30 characters of notes per reading. 16 groups of readings
Maximum number of readings =
(32000 – (16 𝑥 44)
20 + 30
= 625 readings
= 1 reading every 46 seconds for 8 hours
In normal use the AP4 should be able to cope with 1 days' data with no problem.