Heath Consultants Odorator - Manual (Page 24)

Appendix C
Therefore the actual value will be 30% of the difference in the chart higher
actual from the chart lower actual. Again, the lower value will be the base
or reference.
30% of (.22 - .15) = .3 x .07 = .021 which is rounded off to .02
Since the actual value base is .15, the actual value will be .15 + .02 = .17% gas.
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