How to Gauge the Relative Air Density

Take the relative air density meter out of its case and place it in a shaded area. Make sure air can flow freely flow through the vent holes in the sides of the air density meter. Ensure that there are no heating or cooling sources near the density meter which may cause inaccurate readings.

Establish a baseline setting for your engine by reading the air density meter on a specific day, then running your engine to determine the best settings for the engine's performance on that particular day. The air density reading taken is the baseline air density. Note the jet settings used to get the best acceleration for the day. This is the baseline jet setting for the baseline air density.

Measure the air density on the second day. Subtract the baseline air density reading from the new air density reading. Determine the change in relative air density by dividing the difference by the baseline reading then multiplying that result by 100 to get a percentage. The resulting number can be used to calculate the jet number changes that are required to get the best engine performance for that specific air density.