Changes for page ANU Seismic Data Loggers

Summary

• Page properties (1 modified, 0 added, 0 removed)

Details

Page properties

Content

...	...	@@ -12,16 +12,12 @@
12	12
13	13	= Power Considerations =
14	14
15		-Both the LPR-200 (or "Low Power Recorder" 200) and TerraSAWR are designed to use as little power as possible.
	15	+Both the LPR-200 (or "Low Power Recorder" 200) and TerraSAWR are designed to use as little power as possible, and more or less use the same amount of power.
16	16
17	17	At 100 Hz and with a GPS cable connected these loggers draw about 220 mW of power once the screen is off (higher sample rates draw more power but only marginally, < 5 mW). Adding a sensor (e.g. a Trillium Compact 120) increases this to approximately 400 mW, or 0.4 volt-amps. So, in theory 7 Ah battery should last about 10 days without a solar panel, but in practice it seems to be a bit closer to 8 which may be due to variability in power drain while in getting GPS locks.
18	18
19		-For very sunny environments (latitudes < 30) a 20 Volt, 10 Watt solar panel should have no issue keeping these loggers alive over the summer months, and assuming unobstructed skies, should also be fine over winter. **However** when possible a 20 Watt panel works best, especially as they usually cost only $10-20 more these days.
	19	+For very sunny environments (latitudes < 30) a 20 Volt, 10 Watt solar panel should have no issue keeping these loggers alive over the summer months, and assuming unobstructed skies should also be fine over winter. **However** when possible a 20 Watt pane works best, especially as they usually cost only $10-20 more these days.
20	20
21		-Measurements of a 20 Watt panel in the Canberra (Aus) area show that in full sun, roughly 0.75 amps are put out. As the LPR-200 and TSAWR loggers step down the solar voltage to 12v, a 20 Watt solar panel realistically provides 9 Watts to a seismic station. Theoretically, 1 hour and 9 minutes of sun per day should keep the battery charge stable. However, in practice, 1 hour and 30 minutes of full sunlight for a 20 Watt solar panel is required to keep these stations at a stable charge (this was tested over a 5 day period under Canberra sun in spring)
22		-
23		-**Note**: It is important to understand 2 main limitations of the solar component of these seismic stations. First, the voltage output of most solar panels will drop significantly if even a small portion of the panel is shaded. This is why 'full' sun is a requirement. Second, 1 hour and 30 minutes of full sun per day will not always be achieved. The sunniest possible location for a seismic station is always ideal.
24		-
25	25	40 Watt panels can also be used, and may be needed for extreme climates, or areas without a full sky view. 60 Watt panels have also been known to work, but this is now reaching the the limit of what the loggers can reasonably handle for extended periods and are not recommended for long term deploys.
26	26
27	27	(% class="box infomessage" %)
...	...	@@ -302,7 +302,6 @@
302	302
303	303
304	304
305		-
306	306	(% class="box" %)
307	307	(((
308	308	= TerraSAWR Specs =
...	...	@@ -369,6 +369,5 @@
369	369
370	370
371	371
372		-
373	373
374	374	)))