Measure fine particles using gravimetric or sensor inputs. See categories, statistics, and uncertainty checks instantly. Download results, share tables, and improve air decisions safely.
| Scenario | Inputs | Output |
|---|---|---|
| Filter gravimetric | mbefore=100.0000 mg, mafter=100.5000 mg, blank=0.0100 mg, volume=240 L, T=25°C, P=101.325 kPa | C ≈ 2,041.67 µg/m³ (illustrative) |
| Sensor time-weighted | 12 µg/m³ for 60 min, 25 µg/m³ for 30 min, 18 µg/m³ for 30 min | TWA = 16.75 µg/m³ |
Net particulate mass is the filter mass gain, corrected by an optional blank: mnet(mg) = (mafter − mbefore) − mblank.
Convert to micrograms and divide by air volume in cubic meters: C(µg/m³) = (mnet × 1000) / V.
If standard correction is enabled, volume is adjusted using ideal gas scaling: Vstd = Vmeas × (Pmeas/Pstd) × (Tstd/Tmeas), with temperatures in Kelvin.
For readings with durations, the time-weighted average is: TWA = Σ(Ci·ti) / Σ(ti). This page also reports min, max, and weighted standard deviation.
Fine particulate matter below 2.5 micrometers can carry acids, metals, soot, and reactive organics. In laboratories and process areas, these particles penetrate deep into lungs and also contaminate sensitive reactions, filters, and analytical balances. A consistent concentration estimate helps compare ventilation performance, evaluate housekeeping controls, and document background conditions during emissions studies or solvent handling.
The gravimetric method treats the sampling filter as a micro-balance experiment. You weigh the conditioned filter before and after sampling, then subtract an optional blank mass change to remove handling artifacts such as moisture uptake. Converting the net mass to micrograms creates a traceable numerator for concentration, suitable for chain-of-custody records and method validation summaries.
Air volume reported by a sampler is influenced by ambient temperature and barometric pressure. For reporting consistency, many protocols normalize measured volume to standard conditions using ideal gas scaling. Applying this correction reduces bias when comparing winter and summer campaigns, indoor and outdoor locations, or sites at different elevations. The calculator shows both measured and corrected volumes to support auditing.
Direct-reading instruments provide rapid concentration estimates but often vary with humidity, aerosol composition, and calibration drift. When readings are logged over uneven time blocks, a time-weighted average captures the overall exposure level: each reading is multiplied by its duration and divided by total minutes. The calculator also reports range and weighted variability to highlight spikes that may drive short-term risk.
Professional reporting benefits from quick sanity checks. Negative net mass typically signals an overcorrected blank, static charge effects, or inconsistent conditioning. Extremely high concentrations can indicate filter overloading, flow faults, or nearby combustion sources. Exporting a structured CSV supports peer review and trend plotting, while a PDF summary attaches easily to inspections, incident notes, or project deliverables. Always pair calculations with documented flow verification, balance calibration, and field notes on humidity, maintenance, and co-pollutants for defensible interpretation. Include sampler flow logs and conditioning times to strengthen traceability during reviews.
Results are reported as micrograms per cubic meter (µg/m³). Gravimetric inputs in milligrams are converted to micrograms, and air volume is converted to cubic meters for consistency.
Enable it when your method requires normalization to standard temperature and pressure. This improves comparability across days, seasons, and elevations, especially when conditions change during sampling.
A negative net mass usually means the blank correction is too large, the filter lost moisture during conditioning, or the weighings were inconsistent. Recheck conditioning time, static control, and balance repeatability.
You can enter between 2 and 12 rows. Blank rows are ignored, and the tool computes a time-weighted average using only valid concentration and duration pairs.
No. The weighted standard deviation highlights fluctuations in logged readings, but it does not include instrument bias, calibration error, or sampling artifacts. Use your protocol’s uncertainty budget for formal reporting.
The CSV stores a snapshot of inputs plus a result summary text. The PDF includes a formatted results section and all submitted inputs, ready to attach to field notes or audit packages.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.