Helium Release Valve

The National Oceanic and Atmospheric Administration (NOAA) developed this release valve to enable a more controlled descent of a balloon rather than the typical burst and parachute method. Mike Manes describes it:


These photographs are of a valvedown device for latex balloons that was developed at NOAA to produce a controlled near-constant descent rate, sans parachute, for their vaporsondes. This prevents adiabatic cooling of the airstream around the balloon from screwing up the PPM-scale water vapor measurements in the stratosphere. NOAA uses a 4" diameter valve on a 3000 gm balloon with a 5 or 6 lb payload, and regularly gets a 1000 fpm constant and very smooth descent. There's still He in the balloon on landing, making visual tracking a piece of cake. They also use a GPS-equipped cutter driver mounted right at the valve to fire it at a predetermined MSL altitude.

We "cloned" a version for a 1200(?) gm bag, using 3" PVC pipe and an acrylic valve plate. The plate is held in place with 15# monofilament fishing line which is cut by a burner on ground command. During our test flight, the cord running up the lift line got twisted like a double-knotted model airplane rubber band, thus developing a bad case of air-gap-osis before we were able to fire the cutter.

Mike Manes


Click on the pictures to view full resolution version

 

 

 

 

 

 

Additional uncaught exception thrown while handling exception.

Original

PDOException: SQLSTATE[HY000]: General error: 1114 The table 'accesslog' is full: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => Helium Release Valve [:db_insert_placeholder_1] => node/131 [:db_insert_placeholder_2] => [:db_insert_placeholder_3] => 54.87.112.36 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => B1tADa0TB0--ayAwhrWRVVBbuBuFWvX-hDRg2qIgJKg [:db_insert_placeholder_6] => 65 [:db_insert_placeholder_7] => 1429616103 ) in statistics_exit() (line 93 of /usr/share/drupal7/modules/statistics/statistics.module).

Additional

PDOException: SQLSTATE[HY000]: General error: 1114 The table 'watchdog' is full: INSERT INTO {watchdog} (uid, type, message, variables, severity, link, location, referer, hostname, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9); Array ( [:db_insert_placeholder_0] => 0 [:db_insert_placeholder_1] => php [:db_insert_placeholder_2] => %type: !message in %function (line %line of %file). [:db_insert_placeholder_3] => a:6:{s:5:"%type";s:12:"PDOException";s:8:"!message";s:786:"SQLSTATE[HY000]: General error: 1114 The table 'accesslog' is full: INSERT INTO {accesslog} (title, path, url, hostname, uid, sid, timer, timestamp) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => Helium Release Valve [:db_insert_placeholder_1] => node/131 [:db_insert_placeholder_2] => [:db_insert_placeholder_3] => 54.87.112.36 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => B1tADa0TB0--ayAwhrWRVVBbuBuFWvX-hDRg2qIgJKg [:db_insert_placeholder_6] => 65 [:db_insert_placeholder_7] => 1429616103 ) ";s:9:"%function";s:17:"statistics_exit()";s:5:"%file";s:55:"/usr/share/drupal7/modules/statistics/statistics.module";s:5:"%line";i:93;s:14:"severity_level";i:3;} [:db_insert_placeholder_4] => 3 [:db_insert_placeholder_5] => [:db_insert_placeholder_6] => http://www.eoss.org/hardware/balloon_tech/he_release_valve/helium_release_valve.htm [:db_insert_placeholder_7] => [:db_insert_placeholder_8] => 54.87.112.36 [:db_insert_placeholder_9] => 1429616103 ) in dblog_watchdog() (line 160 of /usr/share/drupal7/modules/dblog/dblog.module).