What needs to be clarified
Identify the readings and check whether differences recur for one parameter, separating display switching, measurement conditions and a possible deviation in the appliance’s measuring channel.
Materials to prepare
- Purifier and photographs showing screen and mode symbols
- Model manual and record of screen-switching sequence
- Comparison meter with method, position and observation times
What to compare
Check symbols, units and the manual’s index description. Record the same parameter simultaneously after the required preparation, considering placement and airflow. Check switching and repeatability. Assess method comparability separately; differences between household displays do not establish sensor failure without a controlled investigation.
Possible outcome of the analysis
A screen-to-quantity table and comparable-observation record may identify supported discrepancies and propose additional measuring-channel checks where the initial data are insufficient.
Limits of the conclusions
A proprietary index cannot be converted to concentration with a simple multiplier. Agreement between displays does not prove accuracy; this examination does not assess medical consequences of indoor air quality.