add an explicit reference to Poron open-cell foam in Appendix A

[fw/altos] / doc / micropeak.txt

diff --git a/doc/micropeak.txt b/doc/micropeak.txt
index 3621a2dcc17cffe23a7bb8a9999fafb1ea3c2d73..b6dd0ddb49c84003a6a51cc5e7b26971ae9abdca 100644 (file)
--- a/doc/micropeak.txt
+++ b/doc/micropeak.txt
@@ -327,10 +327,16 @@ Keith Packard <keithp@keithp.com>; Bdale Garbee <bdale@gag.com>
        sensor out of direct sunlight.
 
        The barometric sensor sampling ports must be able to
-       "breathe", both by not being covered by foam or tape or other
-       materials that might directly block the hole on the top of the
-       sensor, and also by having a suitable static vent to outside
-       air.
+       "breathe", both by not being covered by solid foam or tape or 
+       other materials that might directly block the hole on the top 
+       of the sensor, and also by having a suitable static vent to 
+       outside air.
+
+       One good solution is to use a small rectangle of Poron 
+       50-30031-12X12P or equivalent to cover the sensor.  This is an
+       open cell foam in 1/32" thickness with an adhesive backing.  It
+       seems to do a good job of blocking sun while still allowing
+       airflow to and from the sensor internals.
 
        As with all other rocketry electronics, Altus Metrum
        altimeters must be protected from exposure to corrosive motor