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

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
        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
 
        As with all other rocketry electronics, Altus Metrum
        altimeters must be protected from exposure to corrosive motor