For the design of pans, evaporators, barometric condensers and in NPSH calculations for pumps it is neccessary to know the atmospheric pressure. While many cane sugar factories are close to the sea, there are those that are at higher altitudes where atmospheric pressure is below the well known 101325 Pa for sea level

There are tables of atmosphic pressure variation with altitude; the table below is the International Standard Atmosphere adapted from Thermodynamic and Transport Properties of Fluids arranged by GFC Rogers and YR Mayhew, 3rd edition

International Standard Atmosphere

Z [m]

p [Pa]

T [K]

ρ [kg/m^{3}]

-2500

135210

304.4

1.5473

-2000

127780

301.2

1.4782

-1500

120700

297.9

1.4114

-1000

113930

294.7

1.3470

-500

107480

291.4

1.2849

0

101325

288.15

1.2250

500

95460

284.9

1.1673

1000

89880

281.7

1.1117

1500

84560

278.4

1.0582

2000

79500

275.2

1.0066

2500

74690

271.9

0.9570

3000

70120

268.7

0.9093

3500

65780

265.4

0.8634

4000

61660

262.2

0.8194

4500

57750

258.9

0.7770

5000

54050

255.7

0.7365

5500

50540

252.4

0.6975

6000

47220

249.2

0.6602

6500

44080

245.9

0.6243

7000

41110

242.7

0.5901

7500

38300

239.5

0.5573

8000

35650

236.2

0.5258

8500

33150

233.0

0.4958

9000

30800

229.7

0.4671

9500

28580

226.5

0.4397

10000

26500

223.3

0.4136

10500

24540

220.0

0.3886

11000

22700

216.8

0.3648

Tables are not convenient for computer calculations: regression formulae have been prepared from the above data for temperature and density; pressure can then be calculated from the universal gas law.