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Balloon Data
Totex balloon Data
| Balloon Weight (gr) | 200 | 300 | 350 | 450 | 500 | 600 | 700 | 800 | 1000 | 1200 | 1500 | 2000 | 3000 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diameter at Release (cm) | 117 | 123 | 125 | 130 | 133 | 142 | 146 | 150 | 157 | 179 | 185 | 195 | 212 |
| Volume at Release (cu.m) | 0.83 | 0.97 | 1.03 | 1.1 | 1.22 | 1.5 | 1.63 | 1.76 | 2.01 | 2.99 | 3.33 | 3.89 | 4.97 |
| Gross Lift (gr) | 960 | 1110 | 1185 | 1335 | 1405 | 1720 | 1870 | 2020 | 2310 | 3440 | 3830 | 4470 | 5720 |
| Nozzle Lift (gr) | 760 | 810 | 835 | 885 | 905 | 1120 | 1170 | 1220 | 1310 | 2240 | 2330 | 2470 | 2720 |
| Payload (gr) | 250 | 250 | 250 | 250 | 250 | 250 | 250 | 250 | 250 | 1050 | 1050 | 1050 | 1050 |
| Recommended Free Lift (gr) | 510 | 560 | 585 | 635 | 655 | 870 | 920 | 970 | 1060 | 1190 | 1280 | 1420 | 1670 |
| Rate of Ascent (m/min) | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 | 320 |
| Diameter at Burst (cm) | 300 | 378 | 412 | 472 | 499 | 602 | 653 | 700 | 786 | 863 | 944 | 1054 | 1300 |
| Volume at Burst (cu m) | 14.1 | 28.3 | 36.6 | 55.1 | 65.1 | 114.2 | 145.8 | 179.6 | 254.3 | 336.5 | 440.5 | 613.1 | 1150.3 |
| Bursting Altitude (km) | 21.2 | 24.7 | 25.9 | 27.7 | 28.4 | 30.8 | 31.8 | 32.6 | 33.9 | 33.2 | 34.2 | 35.4 | 37.9 |
Its worth noting that the data above is based on the use of Hydrogen rather than Helium.
The Balloon Gross Lift is the lift generated by the volume of Gas. Hydrogen has a density of about 0.09 kg/cu m and air about 1.2 kg/cu m at normal atmospheric pressure - generating a lift of a bit over 1.1kg/cu m. Helium has a density of about 0.17Kg/cu m - generating a lift of a bit over 1.0Kg/cu m. Subtract the Balloon Weight plus the Payload weight form the Gross Lift to give the free lift. The Recommended Free Lift gives a Rate of Ascent of 320m/min (a bit over 1000ft per minute).
Heavier payloads can be carried than the values above - this will either reduce ascent rate, burst altitude (if the balloon is further inflated to compensate) or both. The following spreadsheet allows you to calculate the affect on burst altitude and ascent rates of various levels of fill and payload. To use: choose the balloon size and fill in the payload weight - then adjust the launch diameter until you get the desired ascent rate (normally about 320m/min) - the volume at launch will tell you how much gas you will need.
:guides:burst1a.xls by Steve Randall
| Balloon size | Payload weight | Helium needed | Free lift | aprox. Burst | |
|---|---|---|---|---|---|
| 300g | 150g | 0.84 cu m | 410g | 84,000ft | 18“ |
| 500g | 250g | 1.29 cu m | 570g | 93,000ft | 18” |
| 800g | 400g | 1.84 cu m | 690g | 108,000ft | 24“ |
| 1000g | 500g | 2.23 cu m | 780g | 112,000 ft | 24” |
| 1200g | 600g | 2.62 cu m | 890g | 115,000 ft | 24“ |
| 1500g | 750g | 3.21 cu m | 1040g | 117,000 ft | 30” |
Helium Cylinder Data
| Size | Volume (cu m) | Approx Price | Price /cu m |
|---|---|---|---|
| Small | 0.25 | £20 BOC (Disposable Cannister) | £80 |
| Large | 0.4 | £30 BOC (Disposable Cannister) | £75 |
| L 10 | 1.81 | £65 LBG | £36 |
| PT 10 | 1.81 | £80 BOC Inc Delivery and Collection | £44 |
| V | 1.81 | £70 BOC You collect and return | £38 |
| N 10 | 2.62 | £95 BOC Inc Delivery and Collection / £50 Lets Party Ipswich | £37 / £19 |
| L 20 | 3.62 | £97 LBG Inc Delivery & Collection | £27 |
| T | 3.62 | £95 BOC You collect and return / £65 Party Days Cambridge | £26 / £18 |
| N 20 | 5.2 | £115 BOC Inc Delivery and Collection / £85 Lets Party Ipswich | £22 / £16 |
| N 30 | 7.82 | £130 BOC Inc Delivery and Collection / £125 Lets Party Ipswich | £17 / £16 |
| L | 9.0 | £150 BOC You Collect and return | £17 |
| L 47 | 9.05 | £168 LBG Inc Delivery & Collection | £19 |
These are 2008 prices - since then some Helium prices have risen - treat the above as a relative guide only.