Project no. : 25307
Title : Test of toy balloons performed for Federal Department of Aviation
Rekvirent : Statens Lufthavensvaesen
Box 744
Ellebjergvej 50
2450 Copenhagen SV, Denmark
Phone 011 45 36 44 48 48
Reference : Hr. Kofoed-Hansen
Test Specimen : 10 pcs. latex balloons (11 inch Qualatex)
10 pcs. mylar balloons (18 inch Anagram)
Test Period : 1992.April.23 - 1992.April.24
Testing done by : Tom Hjerting Nielsen
Susanne Otto
Signature : Original Signed by Susanne Otto
The Federal Department of Aviation has until now had the understanding that toy balloons attain a maximum height of a couple of hundred meters, but have now received information that indicates that they can go much higher and with that become a larger danger for air traffic than previously considered.
Therefore, testing is performed with the purpose of determining the height at which balloons explode. The height is determined with the help of a vacuum chamber.
At Electronic Central, tests were performed on toy balloons for the Federal Department of Aviation. The purpose of the tests was to determine the height at which balloons explode.
The tests were performed in a vacuum chamber, where the pressure was slowly reduced and the temperature was reduced simultaneously. Notes were made at which pressure the balloons exploded. The pressure can be converted to an equivalent height.
The tests were performed on two types of toy balloons: 18" mylar and 11" latex.
As received from CHA CHA balloon company, Allerod, 1992.April.23:
10 pcs. latex balloons, 11" diameter (Qualatex)
10 pcs. mylar balloons, 18" diameter (Anagram)
The balloons were delivered, filled with 14 liters of helium.
Thermal vacuum chamber, EC type TVK-2K
EC no. U2401
Date of last calibration: not relevant
U-tube manometer (absolute pressure gage?)
EC no. 23996
Date of last calibration: not relevant
Normal pressure was checked several times during testing according to
EC no. 23742 (Aneroid Barometer)
This chapter describes the tests performed with consideration of the procedure and results.
The tests were performed according to the following procedures.
5 balloons at a time were installed in the vacuum chamber. The pressure in the chamber was gradually reduced. The temperature in the chamber was reduced to -20*C. The pressure at which each balloon explodes is noted together with eventual comments. When all balloons have exploded the temperature and pressure in the chamber are increased to standard laboratory conditions.
First the 10 latex balloons were tested and then the 10 mylar balloons were tested.
The test was carried out as described. Fig 1 and 2 show the test specimens in the vacuum chamber.
(The actual figures have been eliminated due to the poor quality of my copy.)
FIG. 1 Latex balloons in vacuum chamber. (on page 6 of original)
FIG. 2 Mylar balloons in vacuum chamber. (on page 7 of original)
The Table on the next page shows the pressure and the equivalent height at which each balloon exploded. The height was found with linear interpolation of values from IEC 68-2-13 and with that ISO standard 2533 (see appendix 1).
Balloon Type Temperature Pressure Height Notes Latex -20.9xC 228 mmHg 9200 m Latex -20.9xC 220 mmHg 9450 m Latex -20.9xC 220 mmHg 9450 m Latex -20.9xC 216 mmHg 9600 m Latex -20.9xC 204 mmHg 9900 m Latex -20.6xC 203 mmHg 9900 m Latex -19.4xC 193 mmHg 10250 m Latex -19.7xC 189 mmHg 10400 m Latex -21.9xC 180 mmHg 10650 m Latex -20.9xC 179 mmHg 10650 m Mylar 13.8xC 677 mmHg 400 m Mylar -6.0xC 644 mmHg 1000 m Note 1 Mylar -6.0xC 644 mmHg 1000 m Note 1 Mylar -20.6xC 582 mmHg 2000 m Note 1 Mylar -20.3xC 549 mmHg 2600 m Note 1 Mylar -21.7xC 559 mmHg 2400 m Note 2 Mylar -20.5xC 549 mmHg 2600 m Note 1 Mylar -20.5xC 499 mmHg 3450 m Mylar -21.1xC 426 mmHg 4650 m
Note 1: 1 balloon sank down to the bottom of the vacuum chamber.
Note 2: 3 balloons sank down to the bottom of the vacuum chamber.
The results of the finished tests can conclude the following:
Latex balloons explode with in the area of 9200 - 10650 meters altitude with a middle value of 9945 meters altitude. In general, the balloons used in the second test exploded at a higher altitude that the balloons used in the first test. This can be attributed to helium loss during the waiting time having resulted in a reduced internal pressure.
The mylar balloons do not go higher than 1000 - 2400 meters before they either explode or lose their "lift". It is noted that there was a wide range in results for the mylar balloons.
Curve for converting pressure and height
Altitude vs PressureIEC 68-213 (ISO 2533)Pressure (mbar)Altitude (meter)20100200300400500600700 0 5000 10000 15000 20000 25000 30000 3500