What is the difference of pm2_5_cf_1 and pm2_5_cf_1_b
Hi @KevinChess
A majority of PurpleAir models contain two laser counters that take two individual PM measurements. More information is available here: What are Channel A and Channel B? The exact answer to your question depends on where you’re getting the data: through the API or from an SD card.
If you’re getting data from an SD card:
pm2_5_cf_1 is the data from the “A” channel, while pm2_5_cf_1_b is the data from the “B” channel.
If you’re getting data through the API
pm2_5_cf_1_b would be the data from the “B” channel. However, pm2_5_cf_1 would be the average of the “A” and “B” channels.