This repository contains the data used for the analysis of the paper "Laboratory Comparison of Low-Cost Particulate Matter Sensors to Measure Transient Events of Pollution - Part B - Particle Number Concentrations (PNC)" which is under submission. The experimental conditions and the instruments used are detailed in Bulot, F.M.J.; Russell, H.S.; Rezaei, M.; Johnson, M.S.; Ossont, S.J.J.; Morris, A.K.R.; Basford, P.J.; Easton, N.H.C.; Foster, G.L.; Loxham, M.; Cox, S.J. Laboratory Comparison of Low-Cost Particulate Matter Sensors to Measure Transient Events of Pollution. Sensors 2020, 20, 2219. https://doi.org/10.3390/s20082219 The files are available in .csv and in .rds (for R) formats. For details about the measurement equipment used during this study, please refer to the methods section of the paper. sensors_raw.csv contains the following headers: Bin0 to Bin15: Alphasense OPC-R1 particle number concentrations for different size bins Bin[1-3-5-7]MToF: mean time of flight of particles within the corresponding size bins of the Alphasense OPC-R1 Checksum: checksum of the Alphasense OPC-R1 SFR: sample flow rate of the Alphasense OPC-R1 Humidity: relative humidity measured by the Alphasense OPC-R1 Temperature: temperature measured by the Alphasense OPC-R1 SamplingPeriod: sampling period of the Alphasense OPC-R1 gr03um, gr05um, gr10um, gr25um, gr50um, gr100um: PNC measured by the Plantower PMS5003 n05, n1, n25, n4, n10: PNC measured by the Sensirion SPS30 humidity: relative humidity measured by a Sensirion SHT-3x temperature: temperature measured by a Sensirion SHT-3x sensor: id of the sensors site: name of the air quality monitor hosting the sensors exp: name of the experiment conducted source: source used to generate PM (incense or candle) variation: whether the sensors were exposed to stable or peak concentrations of PM pollution date: date in format yyyy-mm-dd HH:MM:SS For more explanations about the fields of individual sensors, please refer to their manual (Alphasense OPC-R1: https://kolegite.com/EE_library/datasheets_and_manuals/sensors/OPC/072-0500_OPC-R1_manual_issue_1_250219.pdf ; Plantower PMS5003: https://www.aqmd.gov/docs/default-source/aq-spec/resources-page/plantower-pms5003-manual_v2-3.pdf ; Sensirion SPS30: https://sensirion.com/products/catalog/SPS30/) ops.csv and ops.rds contains the readings from the OPS with the following cut sizes for the bins: Bin 1 Cut Point (um),0.300 Bin 2 Cut Point (um),0.374 Bin 3 Cut Point (um),0.465 Bin 4 Cut Point (um),0.579 Bin 5 Cut Point (um),0.721 Bin 6 Cut Point (um),0.897 Bin 7 Cut Point (um),1.117 Bin 8 Cut Point (um),1.391 Bin 9 Cut Point (um),1.732 Bin 10 Cut Point (um),2.156 Bin 11 Cut Point (um),2.685 Bin 12 Cut Point (um),3.343 Bin 13 Cut Point (um),4.162 Bin 14 Cut Point (um),5.182 Bin 15 Cut Point (um),6.451 Bin 16 Cut Point (um),8.031 Bin 17 Cut Point (um),10.000 nanotracer.csv and nanotracer.rds contain the measurements from the Nanotracer: N.1.: particles/cm3 dp_avg.1.: mean diameter of the particles (nm) P.1.: S_al.1.: Lung Deposited Surface Area in um2/cm3 experimental_conditions.csv and experimental_conditions.rds contain the end dates and start dates of each of the experiment conducted. "pm100_cf1","pm10_cf1","pm25_cf1"