Specifications - Meteorological Balloons.pdf

U.S. ARMY

YUMA PROVING GROUND

SPECIFICATION FOR

METEOROLOGICAL BALLOONS

Specification for Meteorological Balloons

U.S. Army Yuma Proving Ground

1.0 REQUIREMENTS

1.1. General

Meteorological balloons supplied in accordance with this specification shall meet all requirements herein. Balloons shall be capable of being safely and successfully released by one person from outside the inflation building or from a launch shelter in the environmental conditions of 3.2.2.

1.2. Environmental Conditions

The meteorological balloons shall meet all specification requirements when subjected to all combinations of the encountered environmental conditions.

1.2.1. Storage Environment

Meteorological balloons, when stored in the Contractor-provided individual packaging, shall meet the requirements of this specification after exposure to all combinations of the following conditions, for a period of 18 months after delivery to USAYPG:

Condition Range

Air Temperature 0C to 35C (32F to 95F)

Air Relative Humidity 15% to 75%

Dust 1 million particles per cubic m, various sizes

Altitude -50.0 m to 3.0 km (164 ft to 9.85 kft)

Radiation Sunlight through office windows and ultraviolet light from office fluorescent lights

1.2.2. Flight Environment Conditions

Meteorological balloons, when configured for a flight, shall meet the requirements of this specification when exposed to all combinations of the following conditions during both day and night flights:

Condition Range

Air Pressure 3.0 hectopascals (hPa) to 1070.0 hPa where the minimum air pressure for a particular balloon designation is limited to the actual atmospheric pressure at the minimum specified bursting altitude

Air Temperature -70C to 50C (-94F to 122F)

Air Relative Humidity 0.0% to saturation

Dust 1 million particles per cubic m, various sizes

Wind speed in flight 0 m/s to 165 m/s (0 ft/s to 541 ft/s)

Hydrometeors (liquid and frozen precipitation)

0.0 mm to 150.0 mm per hr (0 to 5.9 in/hr)

Maximum Icing

Conditions

0.0254 cm (0.01 in) in 6 mins

Radiation and

Atmospheric Chemistry

Exposure during flight to all radiation and chemicals occurring in the atmosphere up to the minimum specified burst altitude over the USA, US Possessions, and adjoining ocean areas.

1.3. Flight Performance Requirements

1.3.1. Flight Preparation

Meteorological balloons shall meet the requirements of this specification after being inflated and tied off with string/twine. The meteorological balloon shall be adequately sealed when the string/twine is tied.

One person shall be able to successfully and routinely accomplish both preparation and launch of the balloon in the environment of 3.2.2. Preparation shall include, but not be limited to, removing the meteorological balloon from its individual packaging; inflating the meteorological balloon from empty; tying off the meteorological balloon to prevent inflation gas escape; and attaching the balloon to radiosonde with string/twine.

1.3.2. Inflation Gas

Performance requirements of this specification shall be met when hydrogen gas only, natural gas only, or helium gas only is used to inflate the balloon.

1.3.3. Payload

Flight performance requirements shall be met with no more than a 325gm (0.72lbs) payload

1.3.4. Performance Percentage Requirements

At least 95.0 percent of the balloons shall meet the minimum burst altitude and minimum average ascension rate in the table below when the sample size is at least as large as required by

3.3.5.

Type of meteorological balloon

Minimum Burst Altitude

(km)

Maximum Average Ascension

Rate (m/min)

150gm 16.0 360.0

350gm 24.0 360.0

1,000gm 33.0 360.0

1.3.5. Balloon Launch

One person shall be able to launch the balloon, radiosonde and parachute from outside a balloon launch shelter in the environment of 3.2.2.

1.3.6. Federal Aviation Administration Requirements

The balloon shall meet all requirements of Federal Aviation Requirement 101 (14 CFR 101.31 to

101.39).

1.3.7. Dispersal of Inflation Gas

The inflation gas of the extensible balloon shall be released to the atmosphere. Burst balloons shall not return to a low altitude with inflation gas in them.

1.4. Physical Specifications

1.4.1. Material

Balloons must be produced using natural latex. They should burst into small pieces, being environmentally friendly and biodegradable.

1.4.1.1. Electrostatic Control

Meteorological balloon material shall not contribute to, or permit the buildup of, electrostatic charges on the meteorological balloon surface. An antistatic agent, if required, applied to the balloon meeting 3.0 Requirements is not prohibited.

1.4.1.2. Uniformity

Balloons shall have a uniform texture and have a consistent aerodynamic cross-section during flight. Balloons should not have a teardrop shape during flight.

1.4.1.3. Dusting

Balloons must be produced with a non-toxic, dry, powdered material which effectively prevents adhesion of the balloon. The powder shall not react with helium or hydrogen. The powered material shall not contribute to the formation of an electrostatic charge during preparation, release, or flight of the balloon.

1.4.1.4. Inflation Gas

Balloons shall not react with hydrogen, natural gas, or helium inflation gas. Sounding balloon material shall not expel or emit any chemical that will react with hydrogen, natural gas, or helium gas.

1.4.2. Maximum Meteorological Balloon Size

Balloon

Type

(grams)

Neck

Diameter

(cm)

Neck

Length

(cm)

Flaccid

Body

Length (cm)

Free

Lift

Nozzle

Lift

(grams)

Gross

Lift

(grams)

Bursting

Altitude

(km)

150 3.0 12.0 75 480 760 880 16.0

350 3.0 12.0 118 585 835 1185 24.0

1,000 3.0 12.0 206 1050 1310 2310 33.0

1.4.3. Neck

The neck shall not rip, shred, perforate, or separate from the balloon body when filled or removed from the inflation nozzle. The edge (free end) of the neck shall be free of nicks or folds.

1.4.3.1. Construction

Balloons must be of one piece construction. The balloon neck must be capable of being launched in very high winds and with extremes gust without separating at the attachment point where the neck and balloon meet. Therefore the neck shall be manufactured with the balloon and not attached to the balloon later.

1.4.3.2. Neck functional requirements

a. The neck shall provide a means to inject the inflation gas during preparation and prevent the loss of the inflation gas.

b. The neck shall provide an ergonomic handle for the person to hold the balloon during its release.

c. The neck shall transmit the restraining forces encountered from the operator during the release in very high winds and with extreme gusts to the rest of the balloon, so the balloon is not overstressed.

d. The neck shall provide a means to attach the tie string connecting the balloon and the radiosonde.

1.5. Manufacturing Requirements

1.5.1. Environmental Impact

Meteorological balloons required by this specification and factory equipment used to produce meteorological balloons required by this specification shall not cause exposure to hazardous substances exceeding the recommended limits provided in United States Center for Disease

Control (CDC), Agency for Toxic Substance and Disease Registry, Minimal Risk Levels for

Hazardous Substances in all of the following circumstances:

a. Meteorological balloon preparation.

b. Flight of the meteorological balloons.

c. Contamination of ground water and streams after flight due to leaching of chemicals from the meteorological balloon.

d. Ingestion of meteorological balloon remains in the ground water and in water bodies.

e. Disposal of meteorological balloons.

f. Exposure of Government employees visiting the factory(s) in preparation for, during, and after manufacture and test of meteorological balloons.

All other environment exposure limits imposed by other Government or Government agencies having jurisdiction are also required as though textually incorporated herein. This includes, but is not limited to, those requirements to protect the factory employees and the community(s) where the factory(s) is (are) located. The Contractor shall supply Material Safety Data Sheets

(MSDS) to the Contracting Officer (KO) with the samples for the balloons and dusting material.

1.5.2. Configuration Control

No change shall be made in design, material chemistry, or production process after submission of

Samples without prior written approval by the KO.

1.5.3. Physical Percentage

A least 99.0 percent of the meteorological balloons of each lot shall meet the size requirements of 3.4.2. The mean arithmetic deviation of the actual weights of individual balloons in a lot shall not differ by more than 10.0 percent.