Part I Calculation of Pressure Conversion Factor
The pressure conversion factor is the number given by the following formula, namely—
where—
-
M =the number of millibars in the pressure of the gas at the meter;
-
A =the number of millibars of pressure to be deducted from M on account of the height of the meter above mean sea level measured at Ordnance Survey datum given by the table below.
TABLE
| Height above sea level in metres | Pressure in millibars to be deducted | Height above sea level in metres | Pressure in millibars to be deducted | Height above sea level in metres | Pressure in millibars to be deducted |
|---|---|---|---|---|---|
| ≤0.0 | 0.00 | >97.5≤100.0 | 12.021 | >197.5≤200.0 | 24.041 |
| >0.0≤2.5 | 0.301 | >100.0≤102.5 | 12.321 | >200.0≤202.5 | 24.342 |
| >2.5≤5.0 | 0.601 | >102.5≤105.0 | 12.622 | >202.5≤205.0 | 24.643 |
| >5.0≤7.5 | 0.902 | >105.0≤107.5 | 12.922 | >205.0≤207.5 | 24.943 |
| >7.5≤10.0 | 1.202 | >107.5≤110.0 | 13.223 | >207.5≤210.0 | 25.244 |
| >10.0≤12.5 | 1.503 | >110.0≤112.5 | 13.523 | >210.0≤212.5 | 25.544 |
| >12.5≤15.0 | 1.803 | >112.5≤115.0 | 13.824 | >212.5≤215.0 | 25.845 |
| >15.0≤17.5 | 2.104 | >115.0≤117.5 | 14.124 | >215.0≤217.5 | 26.145 |
| >17.5≤20.0 | 2.404 | >117.5≤120.0 | 14.425 | >217.5≤220.0 | 26.446 |
| >20.0≤22.5 | 2.705 | >120.0≤122.5 | 14.725 | >220.0≤222.5 | 26.746 |
| >22.5≤25.0 | 3.005 | >122.5≤125.0 | 15.026 | >222.5≤225.0 | 27.047 |
| >25.0≤27.5 | 3.306 | >125.0≤127.5 | 15.326 | >225.0≤227.5 | 27.347 |
| >27.5≤30.0 | 3.606 | >127.5≤130.0 | 15.627 | >227.5≤230.0 | 27.648 |
| >30.0≤32.5 | 3.907 | >130.0≤132.5 | 15.927 | >230.0≤232.5 | 27.948 |
| >32.5≤35.0 | 4.207 | >132.5≤135.0 | 16.228 | >232.5≤235.0 | 28.249 |
| >35.0≤37.5 | 4.508 | >135.0≤137.5 | 16.529 | >235.0≤237.5 | 28.549 |
| >37.5≤40.0 | 4.808 | >137.5≤140.0 | 16.829 | >237.5≤240.0 | 28.850 |
| >40.0≤42.5 | 5.109 | >140.0≤142.5 | 17.130 | >240.0≤242.5 | 29.150 |
| >42.5≤45.0 | 5.409 | >142.5≤145.0 | 17.430 | >242.5≤245.0 | 29.451 |
| >45.0≤47.5 | 5.710 | >145.0≤147.5 | 17.731 | >245.0≤247.5 | 29.751 |
| >47.5≤50.0 | 6.010 | >147.5≤150.0 | 18.031 | >247.5≤250.0 | 30.052 |
| >50.0≤52.5 | 6.311 | >150.0≤152.5 | 18.332 | >250.0≤252.5 | 30.352 |
| >52.5≤55.0 | 6.611 | >152.5≤155.0 | 18.632 | >252.5≤255.0 | 30.653 |
| >55.0≤57.5 | 6.912 | >155.0≤157.5 | 18.933 | >255.0≤257.5 | 30.953 |
| >57.5≤60.0 | 7.212 | >157.5≤160.0 | 19.233 | >257.5≤260.0 | 31.254 |
| >60.0≤62.5 | 7.513 | >160.0≤162.5 | 19.534 | >260.0≤262.5 | 31.554 |
| >62.5≤65.0 | 7.813 | >162.5≤165.0 | 19.834 | >262.5≤265.0 | 31.855 |
| >65.0≤67.5 | 8.114 | >165.0≤167.5 | 20.135 | >265.0≤267.5 | 32.155 |
| >67.5≤70.0 | 8.415 | >167.5≤170.0 | 20.435 | >267.5≤270.0 | 32.456 |
| >70.0≤72.5 | 8.715 | >170.0≤172.5 | 20.736 | >270.0≤272.5 | 32.757 |
| >72.5≤75.0 | 9.016 | >172.5≤175.0 | 21.036 | >272.5≤275.0 | 33.057 |
| >75.0≤77.5 | 9.316 | >175.0≤177.5 | 21.337 | >275.0≤277.5 | 33.358 |
| >77.5≤80.0 | 9.617 | >177.5≤180.0 | 21.637 | >277.5≤280.0 | 33.658 |
| >80.0≤82.5 | 9.917 | >180.0≤182.5 | 21.938 | >280.0≤282.5 | 33.959 |
| >82.5≤85.0 | 10.218 | >182.5≤185.0 | 22.238 | >282.5≤285.0 | 34.259 |
| >85.0≤87.5 | 10.518 | >185.0≤187.5 | 22.539 | >285.0≤287.5 | 34.560 |
| >87.5≤90.0 | 10.819 | >187.5≤190.0 | 22.839 | >287.5≤290.0 | 34.860 |
| >90.0≤92.5 | 11.119 | >190.0≤192.5 | 23.140 | >290.0≤292.5 | 35.161 |
| >92.5≤95.0 | 11.420 | >192.5≤195.0 | 23.440 | >292.5≤295.0 | 35.461 |
| >95.0≤97.5 | 11.720 | >195.0≤197.5 | 23.741 | >295.0 | 35.762 |