The “Error from @ Pressure” tab shows the range of errors that could occur when testing to a lower pressure when you desire a result at a higher pressure. An example would be if you wanted to test a building at 50 Pa but could achieve only 15 Pa; the spreadsheet shows that the error added could be +13 to -17%.

The other tab gives a calculation for EqLA and EfLA which can be taken at different pressures. NRCan is thinking of doing this for EqLA10 which is in the Canadian CGSB Standard but because it’s at 10 Pa, the result is unstable; it would be more stable if referenced to 50 Pa. If n=0.5 then value at any pressure is the same. Only when n is greater than 0.5 does the result at a higher pressure become greater.