The ornamental design for air quality measuring apparatus, as shown and described.
1. Air quality measuring apparatus
1.1: Perspective
1.2: Front
1.3: Back
1.4: Top
1.5: Bottom
1.6: Left
1.7: Right
An air quality measuring apparatus installed indoor or outdoor is used to measure the concentration of air pollutants and particulate matters; the lower part of the apparatus made of a transparent or translucent material changes its color depending on the status of air quality.