Judging by the 4 other planes I have and they were all slightly different. I assume they're good for checking something quickly, but don't rely on them for ultimate accuracy.
π Dioxide Controller for Digital Gas Monitoring
5 Review
π Enhanced Precision with Backlit Professional Manometer for Differential Ventilation
6 Review
π¬οΈ Advanced 3-in-1 Indoor Air Quality Monitor with CO2/RH/Temp Data Logging and Audible Alarm - NDIR Sensor Technology
8 Review
π§ UEi Test Instruments DAFM3B Digital Multimeter
6 Review