---
title: "Environmental Monitoring Parameters & Glossary | Aethair"
description: "Glossary of 90 environmental monitoring parameters (particulate matter, gases and VOCs, water quality, noise, weather, and more) with definitions, units,…"
url: https://aethair.io/parameters/
---

Resources · Measurements

# Environmental Monitoring Parameters

What each one is, what it is called, and what measures it

Every parameter the platform measures, with its unit, the other names it goes by, and the standards that set limits on it. Each page shows the Aethair monitors, cartridges, and third-party instruments that measure it.

[Schedule a call](https://calendly.com/d/ctdd-mkr-v9v/aethair-demo-website) [Build a Configuration](https://aethair.io/build/)

In the catalog

- [**90** parameters, defined](#group-particulate-matter)
- [**9** groups](#parameter-groups)
- [**40** standards with limits](https://aethair.io/standards/)
- [**224** device models measure them](https://aethair.io/sensors/)

[Particulate Matter 9](#group-particulate-matter) [Gases & VOCs 19](#group-gases-vocs) [Meteorology 15](#group-meteorology) [Water Quality 21](#group-water-quality) [Fluid / Level / Flow 7](#group-fluid-level-flow) [Noise 9](#group-noise) [Radiation & Light 5](#group-radiation-light) [Agriculture 4](#group-agriculture) [Analog / I/O 1](#group-analog-i-o)

## Particulate Matter

### [Total PM / Mass Conc.](https://aethair.io/parameters/pm_total/)

[µg/m³ · 6 devices & options](https://aethair.io/parameters/pm_total/)

[Total suspended particulate mass concentration across all measured sizes.](https://aethair.io/parameters/pm_total/)

[Also: TSP · total suspended particulates · total dust · aerosol mass concentration](https://aethair.io/parameters/pm_total/)

### [PM2.5](https://aethair.io/parameters/pm2_5/)

[µg/m³ · 5 devices & options](https://aethair.io/parameters/pm2_5/)

[Fine particulate matter ≤2.5 µm that penetrates deep into the lungs and can enter the bloodstream. A primary ambient…](https://aethair.io/parameters/pm2_5/)

[Also: fine particulate matter · fine dust · particulate matter 2.5](https://aethair.io/parameters/pm2_5/)

### [PM10](https://aethair.io/parameters/pm10/)

[µg/m³ · 5 devices & options](https://aethair.io/parameters/pm10/)

[Inhalable ('thoracic') particulate ≤10 µm; includes coarse dust that deposits in the upper airways.](https://aethair.io/parameters/pm10/)

[Also: coarse particulate matter · inhalable dust · particulate matter 10](https://aethair.io/parameters/pm10/)

### [PM1](https://aethair.io/parameters/pm1/)

[µg/m³ · 4 devices & options](https://aethair.io/parameters/pm1/)

[Fine particulate matter ≤1 µm aerodynamic diameter, the finest fraction, which reaches the deep alveolar regions of the…](https://aethair.io/parameters/pm1/)

[Also: submicron particles](https://aethair.io/parameters/pm1/)

### [PM4 (Respirable)](https://aethair.io/parameters/pm4/)

[µg/m³ · 2 devices & options](https://aethair.io/parameters/pm4/)

[Respirable particulate ≤4 µm (respirable convention); the fraction reaching the gas-exchange region, used in…](https://aethair.io/parameters/pm4/)

[Also: respirable dust · respirable fraction](https://aethair.io/parameters/pm4/)

### [Sample Flow](https://aethair.io/parameters/sample_flow/)

[L/min · 2 devices & options](https://aethair.io/parameters/sample_flow/)

[Sample flow is the rate at which an instrument draws air through its inlet, and on this platform it is an instrument's…](https://aethair.io/parameters/sample_flow/)

[Also: air flow · sample flow rate](https://aethair.io/parameters/sample_flow/)

### [Particle Count (by size)](https://aethair.io/parameters/particle_count/)

[particles · 3 devices & options](https://aethair.io/parameters/particle_count/)

[Airborne particle number concentration counted in discrete size bins (e.g. 0.3–10 µm); used for cleanrooms and aerosol…](https://aethair.io/parameters/particle_count/)

[Also: particle counter · particle number concentration · airborne particle counting](https://aethair.io/parameters/particle_count/)

### [Respirable Crystalline Silica](https://aethair.io/parameters/silica/)

[µg/m³ · 1 device or option](https://aethair.io/parameters/silica/)

[Respirable crystalline silica (RCS); a carcinogenic dust fraction with strict occupational exposure limits.](https://aethair.io/parameters/silica/)

[Also: RCS · quartz dust · crystalline silica · respirable silica](https://aethair.io/parameters/silica/)

### [Black Carbon](https://aethair.io/parameters/black_carbon/)

[ng/m³ · 1 device or option](https://aethair.io/parameters/black_carbon/)

[Black carbon (soot) from combustion, measured by 880 nm optical absorption. A climate forcer and a marker of traffic…](https://aethair.io/parameters/black_carbon/)

[Also: BC · elemental carbon · aethalometer · aae wb](https://aethair.io/parameters/black_carbon/)

## Gases & VOCs

### [Carbon Dioxide (CO₂)](https://aethair.io/parameters/co2/)

[ppm · 6 devices & options](https://aethair.io/parameters/co2/)

[Carbon dioxide: an indicator of ventilation and indoor air quality, and an asphyxiant at high concentration.](https://aethair.io/parameters/co2/)

[Also: CO2 level · CO2 concentration](https://aethair.io/parameters/co2/)

### [VOC (Total)](https://aethair.io/parameters/voc/)

[ppb · 7 devices & options](https://aethair.io/parameters/voc/)

[Total volatile organic compounds: a broadband, PID-based indicator of solvent and fuel vapors.](https://aethair.io/parameters/voc/)

[Also: volatile organic compounds · TVOC · total VOC](https://aethair.io/parameters/voc/)

### [Hydrogen Sulfide (H₂S)](https://aethair.io/parameters/h2s/)

[ppm · 6 devices & options](https://aethair.io/parameters/h2s/)

[Hydrogen sulfide: a toxic, corrosive gas with a rotten-egg odor, common in wastewater and oil & gas.](https://aethair.io/parameters/h2s/)

[Also: hydrogen sulphide · sewer gas](https://aethair.io/parameters/h2s/)

### [Carbon Monoxide (CO)](https://aethair.io/parameters/co/)

[ppm · 7 devices & options](https://aethair.io/parameters/co/)

[Carbon monoxide: a toxic, odorless combustion gas that binds to hemoglobin. An ambient and occupational hazard.](https://aethair.io/parameters/co/)

[Also: CO gas](https://aethair.io/parameters/co/)

### [Methane (CH₄)](https://aethair.io/parameters/ch4/)

[ppm · 6 devices & options](https://aethair.io/parameters/ch4/)

[Methane: a combustible gas (explosion hazard, measured in %LEL) and a potent greenhouse gas.](https://aethair.io/parameters/ch4/)

[Also: natural gas](https://aethair.io/parameters/ch4/)

### [Oxygen (O₂)](https://aethair.io/parameters/o2/)

[% · 5 devices & options](https://aethair.io/parameters/o2/)

[Oxygen concentration; critical for confined-space safety (deficiency below 19.5 %, enrichment above 23.5 %).](https://aethair.io/parameters/o2/)

[Also: oxygen level · oxygen deficiency](https://aethair.io/parameters/o2/)

### [Sulfur Dioxide (SO₂)](https://aethair.io/parameters/so2/)

[ppm · 4 devices & options](https://aethair.io/parameters/so2/)

[Sulfur dioxide: a criteria pollutant from fossil-fuel combustion that irritates the respiratory system.](https://aethair.io/parameters/so2/)

[Also: sulphur dioxide](https://aethair.io/parameters/so2/)

### [Nitric Oxide (NO)](https://aethair.io/parameters/no/)

[ppm · 3 devices & options](https://aethair.io/parameters/no/)

[Nitric oxide: a combustion gas and a precursor to NO₂ and ozone.](https://aethair.io/parameters/no/)

### [Nitrogen Dioxide (NO₂)](https://aethair.io/parameters/no2/)

[ppm · 5 devices & options](https://aethair.io/parameters/no2/)

[Nitrogen dioxide: a criteria pollutant, respiratory irritant, and marker of traffic combustion.](https://aethair.io/parameters/no2/)

### [Ammonia (NH₃)](https://aethair.io/parameters/nh3/)

[ppm · 2 devices & options](https://aethair.io/parameters/nh3/)

[Ammonia; a toxic, pungent gas from agriculture, refrigeration, and wastewater.](https://aethair.io/parameters/nh3/)

[Also: ammonia gas](https://aethair.io/parameters/nh3/)

### [Combustible (LEL)](https://aethair.io/parameters/lel/)

[%LEL · 1 device or option](https://aethair.io/parameters/lel/)

[Combustible-gas concentration as a percentage of the Lower Explosive Limit, a key flammability and explosion-safety…](https://aethair.io/parameters/lel/)

[Also: combustible gas · explosive gas · flammable gas · lower explosive limit](https://aethair.io/parameters/lel/)

### [Chlorine (Cl₂)](https://aethair.io/parameters/cl2/)

[ppm · 1 device or option](https://aethair.io/parameters/cl2/)

[Chlorine gas; a toxic oxidizing irritant.](https://aethair.io/parameters/cl2/)

[Also: chlorine gas](https://aethair.io/parameters/cl2/)

### [BTEX / speciated VOC](https://aethair.io/parameters/btex/)

[ppb · 1 device or option](https://aethair.io/parameters/btex/)

[Speciated volatile organics (benzene, toluene, ethylbenzene, xylenes, and chlorinated VOCs) from gas chromatography.](https://aethair.io/parameters/btex/)

[Also: benzene · toluene · ethylbenzene · xylene](https://aethair.io/parameters/btex/)

### [Mercury (Hg)](https://aethair.io/parameters/hg/)

[mg/m³ · 1 device or option](https://aethair.io/parameters/hg/)

[Mercury vapor: a neurotoxic heavy-metal vapor.](https://aethair.io/parameters/hg/)

[Also: mercury vapor · mercury vapour](https://aethair.io/parameters/hg/)

### [Hydrogen (H₂)](https://aethair.io/parameters/h2/)

[ppm · 1 device or option](https://aethair.io/parameters/h2/)

[Hydrogen is a flammable gas, and continuous H₂ detection belongs to the fixed gas-detection systems used in mining and…](https://aethair.io/parameters/h2/)

### [Ozone (O₃)](https://aethair.io/parameters/o3/)

[ppb · 2 devices & options](https://aethair.io/parameters/o3/)

[Ozone: a secondary photochemical pollutant and respiratory irritant, and an occupational hazard near generators.](https://aethair.io/parameters/o3/)

[Also: ground-level ozone](https://aethair.io/parameters/o3/)

### [Hydrogen Chloride (HCl)](https://aethair.io/parameters/hcl/)

[ppm · 1 device or option](https://aethair.io/parameters/hcl/)

[Hydrogen chloride (HCl), a corrosive acid gas from industrial processes and incineration, and a toxic respiratory…](https://aethair.io/parameters/hcl/)

[Also: hydrochloric acid gas](https://aethair.io/parameters/hcl/)

### [Hydrogen Fluoride (HF)](https://aethair.io/parameters/hf/)

[ppm · 1 device or option](https://aethair.io/parameters/hf/)

[Hydrogen fluoride (HF), a highly toxic and corrosive gas from aluminum smelting, glass etching, and refining.](https://aethair.io/parameters/hf/)

### [Formaldehyde (CH₂O)](https://aethair.io/parameters/ch2o/)

[mg/m³ · 2 devices & options](https://aethair.io/parameters/ch2o/)

[Formaldehyde (CH₂O/HCHO), a colorless carcinogenic VOC emitted by pressed-wood products, insulation, furnishings, and…](https://aethair.io/parameters/ch2o/)

[Also: HCHO · CH2O · formaldehyde monitor](https://aethair.io/parameters/ch2o/)

## Meteorology

### [Barometric Pressure](https://aethair.io/parameters/pressure/)

[hPa · 14 devices & options](https://aethair.io/parameters/pressure/)

[Barometric / atmospheric pressure.](https://aethair.io/parameters/pressure/)

[Also: atmospheric pressure · air pressure · absolute air pressure · relative air pressure](https://aethair.io/parameters/pressure/)

### [Air Temperature](https://aethair.io/parameters/temperature/)

[°C · 16 devices & options](https://aethair.io/parameters/temperature/)

[Ambient air (dry-bulb) temperature.](https://aethair.io/parameters/temperature/)

[Also: ambient temperature · dry bulb · sample temp](https://aethair.io/parameters/temperature/)

### [Relative Humidity](https://aethair.io/parameters/humidity/)

[% · 14 devices & options](https://aethair.io/parameters/humidity/)

[Relative humidity of air.](https://aethair.io/parameters/humidity/)

[Also: RH · air moisture · sample rh](https://aethair.io/parameters/humidity/)

### [Wind Speed](https://aethair.io/parameters/wind_speed/)

[m/s · 7 devices & options](https://aethair.io/parameters/wind_speed/)

[Horizontal wind speed.](https://aethair.io/parameters/wind_speed/)

[Also: anemometer · wind velocity · wind gust](https://aethair.io/parameters/wind_speed/)

### [Wind Direction](https://aethair.io/parameters/wind_direction/)

[° · 7 devices & options](https://aethair.io/parameters/wind_direction/)

[Horizontal wind direction (0–360°).](https://aethair.io/parameters/wind_direction/)

[Also: wind vane · wind bearing · compass](https://aethair.io/parameters/wind_direction/)

### [Dew Point](https://aethair.io/parameters/dew_point/)

[°C · 7 devices & options](https://aethair.io/parameters/dew_point/)

[Dew-point temperature; the temperature at which air becomes saturated.](https://aethair.io/parameters/dew_point/)

[Also: dewpoint temperature · sample dewpoint](https://aethair.io/parameters/dew_point/)

### [Wind Chill](https://aethair.io/parameters/wind_chill/)

[°C · 3 devices & options](https://aethair.io/parameters/wind_chill/)

[Wind-chill (apparent cold) temperature.](https://aethair.io/parameters/wind_chill/)

[Also: wind chill temperature](https://aethair.io/parameters/wind_chill/)

### [Precipitation](https://aethair.io/parameters/precipitation/)

[mm · 3 devices & options](https://aethair.io/parameters/precipitation/)

[Accumulated precipitation depth.](https://aethair.io/parameters/precipitation/)

[Also: rainfall · rain gauge · storm rain · rain day](https://aethair.io/parameters/precipitation/)

### [Precipitation Intensity](https://aethair.io/parameters/precip_intensity/)

[mm/h · 3 devices & options](https://aethair.io/parameters/precip_intensity/)

[Instantaneous precipitation (rain) rate.](https://aethair.io/parameters/precip_intensity/)

[Also: rain rate · rainfall intensity · rainfall · peak rain intensity](https://aethair.io/parameters/precip_intensity/)

### [Heat Index](https://aethair.io/parameters/heat_index/)

[°C · 5 devices & options](https://aethair.io/parameters/heat_index/)

[Heat index / apparent temperature combining heat and humidity.](https://aethair.io/parameters/heat_index/)

[Also: feels-like temperature · apparent temperature · humidex](https://aethair.io/parameters/heat_index/)

### [Wet Bulb Temperature](https://aethair.io/parameters/wet_bulb/)

[°C · 2 devices & options](https://aethair.io/parameters/wet_bulb/)

[Wet-bulb temperature: an input for evaporative cooling and heat-stress calculations.](https://aethair.io/parameters/wet_bulb/)

[Also: wet bulb](https://aethair.io/parameters/wet_bulb/)

### [Absolute Humidity](https://aethair.io/parameters/absolute_humidity/)

[% · 1 device or option](https://aethair.io/parameters/absolute_humidity/)

[Absolute humidity is the amount of water vapor actually in the air, independent of temperature; relative humidity, by…](https://aethair.io/parameters/absolute_humidity/)

### [WBGT (Heat Stress)](https://aethair.io/parameters/wbgt/)

[°C · 1 device or option](https://aethair.io/parameters/wbgt/)

[Wet-Bulb Globe Temperature (WBGT): the standard composite index for occupational heat-stress assessment.](https://aethair.io/parameters/wbgt/)

[Also: wet bulb globe temperature · heat stress index](https://aethair.io/parameters/wbgt/)

### [Lightning](https://aethair.io/parameters/lightning/)

[count · 0 devices & options](https://aethair.io/parameters/lightning/)

[Detected lightning strike events.](https://aethair.io/parameters/lightning/)

[Also: lightning detection · storm detection](https://aethair.io/parameters/lightning/)

### [Differential Pressure](https://aethair.io/parameters/differential_pressure/)

[Pa · 1 device or option](https://aethair.io/parameters/differential_pressure/)

[Differential pressure between two spaces or across an air filter, used to verify room pressurization (cleanrooms,…](https://aethair.io/parameters/differential_pressure/)

[Also: DP · delta P · pressure drop · filter pressure](https://aethair.io/parameters/differential_pressure/)

## Water Quality

### [Water Temperature](https://aethair.io/parameters/water_temperature/)

[°C · 7 devices & options](https://aethair.io/parameters/water_temperature/)

[Water temperature.](https://aethair.io/parameters/water_temperature/)

[Also: water temp](https://aethair.io/parameters/water_temperature/)

### [pH](https://aethair.io/parameters/ph/)

[pH · 5 devices & options](https://aethair.io/parameters/ph/)

[pH: the acidity or alkalinity of water.](https://aethair.io/parameters/ph/)

[Also: pH level · water acidity](https://aethair.io/parameters/ph/)

### [ORP](https://aethair.io/parameters/orp/)

[mV · 5 devices & options](https://aethair.io/parameters/orp/)

[Oxidation-reduction (redox) potential of water.](https://aethair.io/parameters/orp/)

[Also: oxidation-reduction potential · redox potential](https://aethair.io/parameters/orp/)

### [Specific Conductance](https://aethair.io/parameters/specific_conductance/)

[µS/cm · 5 devices & options](https://aethair.io/parameters/specific_conductance/)

[Conductivity normalized to 25 °C (specific conductance).](https://aethair.io/parameters/specific_conductance/)

[Also: SPC · specific conductivity](https://aethair.io/parameters/specific_conductance/)

### [Salinity](https://aethair.io/parameters/salinity/)

[PSU · 5 devices & options](https://aethair.io/parameters/salinity/)

[Salinity derived from conductivity/temperature.](https://aethair.io/parameters/salinity/)

[Also: salt content · PSU](https://aethair.io/parameters/salinity/)

### [TDS](https://aethair.io/parameters/tds/)

[mg/L · 5 devices & options](https://aethair.io/parameters/tds/)

[Total dissolved solids.](https://aethair.io/parameters/tds/)

[Also: total dissolved solids](https://aethair.io/parameters/tds/)

### [Turbidity](https://aethair.io/parameters/turbidity/)

[NTU · 5 devices & options](https://aethair.io/parameters/turbidity/)

[Water turbidity (light scattering by suspended particles).](https://aethair.io/parameters/turbidity/)

[Also: water clarity · NTU](https://aethair.io/parameters/turbidity/)

### [Dissolved Oxygen](https://aethair.io/parameters/do/)

[mg/L · 5 devices & options](https://aethair.io/parameters/do/)

[Dissolved oxygen in water; a key aquatic-health metric.](https://aethair.io/parameters/do/)

[Also: oxygen saturation · DO probe · do concentration · do saturation](https://aethair.io/parameters/do/)

### [Chlorophyll](https://aethair.io/parameters/chlorophyll/)

[µg/L · 5 devices & options](https://aethair.io/parameters/chlorophyll/)

[Chlorophyll-a fluorescence, an indicator of algal biomass.](https://aethair.io/parameters/chlorophyll/)

[Also: chlorophyll-a · algae concentration · chlorophyll cell](https://aethair.io/parameters/chlorophyll/)

### [Nitrate (NO₃)](https://aethair.io/parameters/nitrate/)

[mg/L · 5 devices & options](https://aethair.io/parameters/nitrate/)

[Nitrate (NO₃) concentration in water, an indicator of nutrient pollution.](https://aethair.io/parameters/nitrate/)

[Also: NO3 · nitrate ion · nitrate nitrogen](https://aethair.io/parameters/nitrate/)

### [Ammonium (NH₄)](https://aethair.io/parameters/ammonium/)

[mg/L · 5 devices & options](https://aethair.io/parameters/ammonium/)

[Ammonium (NH4) concentration in water.](https://aethair.io/parameters/ammonium/)

[Also: NH4 · ammonia nitrogen · ammonium ion](https://aethair.io/parameters/ammonium/)

### [Dissolved Ammonia (NH₃)](https://aethair.io/parameters/ammonia/)

[mg/L · 5 devices & options](https://aethair.io/parameters/ammonia/)

[Ammonia (NH₃) is the un-ionized, dissolved form of nitrogen in water, reported in milligrams per liter.](https://aethair.io/parameters/ammonia/)

[Also: ammonia nitrogen · un-ionized ammonia · unionized ammonia](https://aethair.io/parameters/ammonia/)

### [Chloride](https://aethair.io/parameters/chloride/)

[mg/L · 5 devices & options](https://aethair.io/parameters/chloride/)

[Chloride ion concentration in water.](https://aethair.io/parameters/chloride/)

[Also: chloride ion](https://aethair.io/parameters/chloride/)

### [Conductivity](https://aethair.io/parameters/conductivity/)

[µS/cm · 5 devices & options](https://aethair.io/parameters/conductivity/)

[Electrical conductivity of water (ion content).](https://aethair.io/parameters/conductivity/)

[Also: EC · electrical conductivity · actual conductivity · nlf conductivity](https://aethair.io/parameters/conductivity/)

### [Ion-Selective (Other Ions)](https://aethair.io/parameters/ion/)

[mg/L · 4 devices & options](https://aethair.io/parameters/ion/)

[Other ion-selective-electrode measurements (fluoride, potassium, metals, etc.).](https://aethair.io/parameters/ion/)

[Also: ion-selective electrode · ISE · total nitrogen · potassium](https://aethair.io/parameters/ion/)

### [Blue-Green Algae](https://aethair.io/parameters/bga/)

[µg/L · 4 devices & options](https://aethair.io/parameters/bga/)

[Blue-green algae (cyanobacteria) pigment fluorescence (phycocyanin/phycoerythrin).](https://aethair.io/parameters/bga/)

[Also: cyanobacteria · phycocyanin · bga pc · bga pe](https://aethair.io/parameters/bga/)

### [Resistivity](https://aethair.io/parameters/resistivity/)

[MΩ·cm · 3 devices & options](https://aethair.io/parameters/resistivity/)

[Resistivity is how strongly water resists an electric current (the inverse of conductivity), so the purer the water,…](https://aethair.io/parameters/resistivity/)

[Also: specific resistance](https://aethair.io/parameters/resistivity/)

### [TSS](https://aethair.io/parameters/tss/)

[mg/L · 3 devices & options](https://aethair.io/parameters/tss/)

[Total suspended solids.](https://aethair.io/parameters/tss/)

[Also: total suspended solids · turbidity to tss](https://aethair.io/parameters/tss/)

### [fDOM / CDOM](https://aethair.io/parameters/fdom/)

[RFU · 3 devices & options](https://aethair.io/parameters/fdom/)

[Fluorescent/colored dissolved organic matter (fDOM/CDOM).](https://aethair.io/parameters/fdom/)

[Also: dissolved organic matter · CDOM](https://aethair.io/parameters/fdom/)

### [Density](https://aethair.io/parameters/density/)

[g/cm³ · 2 devices & options](https://aethair.io/parameters/density/)

[Water density is the mass of water per unit volume, and it changes with the water's temperature and the salts dissolved…](https://aethair.io/parameters/density/)

[Also: density of water](https://aethair.io/parameters/density/)

### [Dissolved CO₂](https://aethair.io/parameters/dissolved_co2/)

[ppm · 1 device or option](https://aethair.io/parameters/dissolved_co2/)

[Dissolved carbon dioxide is the CO₂ held in solution in water.](https://aethair.io/parameters/dissolved_co2/)

[Also: dissolved carbon dioxide](https://aethair.io/parameters/dissolved_co2/)

## Fluid / Level / Flow

### [Water Level / Depth](https://aethair.io/parameters/water_level/)

[m · 6 devices & options](https://aethair.io/parameters/water_level/)

[Water level / depth (pressure- or acoustic-derived).](https://aethair.io/parameters/water_level/)

[Also: water depth · stage height · level sensor · vented depth](https://aethair.io/parameters/water_level/)

### [Water Pressure](https://aethair.io/parameters/water_pressure/)

[cmH₂O · 5 devices & options](https://aethair.io/parameters/water_pressure/)

[Water pressure, in this context, is the hydrostatic pressure exerted by a column of water above a submerged sensor,…](https://aethair.io/parameters/water_pressure/)

[Also: water column · water column pressure · hydrostatic pressure](https://aethair.io/parameters/water_pressure/)

### [Volume (totalized)](https://aethair.io/parameters/volume/)

[— · 1 device or option](https://aethair.io/parameters/volume/)

[Totalized volume.](https://aethair.io/parameters/volume/)

[Also: totalized flow · flow total · volume 1](https://aethair.io/parameters/volume/)

### [Flow Rate](https://aethair.io/parameters/flow/)

[— · 1 device or option](https://aethair.io/parameters/flow/)

[Volumetric flow rate (open-channel or pipe).](https://aethair.io/parameters/flow/)

[Also: flow meter · discharge measurement · flow 1 · flow setpoint](https://aethair.io/parameters/flow/)

### [Fluid Differential Pressure](https://aethair.io/parameters/differential_pressure_fluid/)

[psi · 1 device or option](https://aethair.io/parameters/differential_pressure_fluid/)

[Differential pressure across a fuel or hydraulic filter or filter/separator vessel, flow-corrected per ATA 103 / EI…](https://aethair.io/parameters/differential_pressure_fluid/)

[Also: fuel filter differential pressure · filter vessel differential pressure · corrected DP · flow-corrected differential pressure](https://aethair.io/parameters/differential_pressure_fluid/)

### [Fluid Particle Count (ISO 4406)](https://aethair.io/parameters/particle_count_fluid/)

[counts/mL · 1 device or option](https://aethair.io/parameters/particle_count_fluid/)

[Fluid (oil/fuel) particle counts reported as ISO 4406 cleanliness codes.](https://aethair.io/parameters/particle_count_fluid/)

[Also: oil cleanliness · ISO cleanliness code · NAS 1638 class](https://aethair.io/parameters/particle_count_fluid/)

### [Velocity](https://aethair.io/parameters/velocity/)

[m/s · 0 devices & options](https://aethair.io/parameters/velocity/)

[Flow velocity.](https://aethair.io/parameters/velocity/)

[Also: flow velocity](https://aethair.io/parameters/velocity/)

## Noise

### [Sound Pressure Level (SPL)](https://aethair.io/parameters/sound_spl/)

[dB · 3 devices & options](https://aethair.io/parameters/sound_spl/)

[Sound Pressure Level, the instantaneous weighted level (A/C/Z, fast/slow/impulse).](https://aethair.io/parameters/sound_spl/)

[Also: decibel level · dB meter · sound level](https://aethair.io/parameters/sound_spl/)

### [Equivalent Continuous Level (Leq)](https://aethair.io/parameters/sound_leq/)

[dB · 3 devices & options](https://aethair.io/parameters/sound_leq/)

[Equivalent continuous sound level (time-averaged energy), the core occupational-noise metric.](https://aethair.io/parameters/sound_leq/)

[Also: average noise level · equivalent continuous sound level](https://aethair.io/parameters/sound_leq/)

### [Peak Level (Lpeak)](https://aethair.io/parameters/sound_lpeak/)

[dB · 2 devices & options](https://aethair.io/parameters/sound_lpeak/)

[Peak sound pressure level (C-weighted peak used for impulse-noise limits).](https://aethair.io/parameters/sound_lpeak/)

[Also: peak noise level](https://aethair.io/parameters/sound_lpeak/)

### [Statistical Level (Ln)](https://aethair.io/parameters/sound_ln/)

[dB · 1 device or option](https://aethair.io/parameters/sound_ln/)

[Statistical / percentile level (e.g. L90 background, L10 intrusive).](https://aethair.io/parameters/sound_ln/)

[Also: percentile noise level · L90 · L10](https://aethair.io/parameters/sound_ln/)

### [Max Level (Lmax)](https://aethair.io/parameters/sound_lmax/)

[dB · 1 device or option](https://aethair.io/parameters/sound_lmax/)

[Maximum sound level over the interval.](https://aethair.io/parameters/sound_lmax/)

[Also: maximum noise level](https://aethair.io/parameters/sound_lmax/)

### [Min Level (Lmin)](https://aethair.io/parameters/sound_lmin/)

[dB · 1 device or option](https://aethair.io/parameters/sound_lmin/)

[Minimum sound level over the interval.](https://aethair.io/parameters/sound_lmin/)

[Also: minimum noise level](https://aethair.io/parameters/sound_lmin/)

### [Average Level (Lavg)](https://aethair.io/parameters/sound_lavg/)

[dB · 1 device or option](https://aethair.io/parameters/sound_lavg/)

[Average sound level (dosimeter, exchange-rate dependent).](https://aethair.io/parameters/sound_lavg/)

[Also: average sound level](https://aethair.io/parameters/sound_lavg/)

### [TWA / Noise Dose](https://aethair.io/parameters/sound_twa/)

[dB · 1 device or option](https://aethair.io/parameters/sound_twa/)

[Time-weighted average / noise dose over the work shift.](https://aethair.io/parameters/sound_twa/)

[Also: noise dose · noise dosimeter reading](https://aethair.io/parameters/sound_twa/)

### [Sound Exposure Level (SEL)](https://aethair.io/parameters/sound_sel/)

[dB · 0 devices & options](https://aethair.io/parameters/sound_sel/)

[Sound Exposure Level (energy of an event normalized to 1 s).](https://aethair.io/parameters/sound_sel/)

## Radiation & Light

### [Solar / Global Radiation](https://aethair.io/parameters/solar_radiation/)

[W/m² · 3 devices & options](https://aethair.io/parameters/solar_radiation/)

[Global (solar) radiation / irradiance.](https://aethair.io/parameters/solar_radiation/)

[Also: pyranometer · solar irradiance · global radiation · solar radiation](https://aethair.io/parameters/solar_radiation/)

### [PAR (Photosynthetically Active Radiation)](https://aethair.io/parameters/par/)

[µmol/s/m² · 1 device or option](https://aethair.io/parameters/par/)

[Photosynthetically active radiation (PAR) is the light in the band that plants and algae use for photosynthesis,…](https://aethair.io/parameters/par/)

### [UV Index](https://aethair.io/parameters/uv/)

[— · 1 device or option](https://aethair.io/parameters/uv/)

[The UV index is the standard scale for the strength of the sun's ultraviolet radiation at the ground, a single unitless…](https://aethair.io/parameters/uv/)

[Also: ultraviolet](https://aethair.io/parameters/uv/)

### [Radon](https://aethair.io/parameters/radon/)

[pCi/L · 1 device or option](https://aethair.io/parameters/radon/)

[Radon gas activity concentration. Radon is a radioactive indoor-air carcinogen.](https://aethair.io/parameters/radon/)

[Also: radon gas · radon test](https://aethair.io/parameters/radon/)

### [Illuminance / Light](https://aethair.io/parameters/light/)

[lux · 1 device or option](https://aethair.io/parameters/light/)

[Illuminance / light level.](https://aethair.io/parameters/light/)

[Also: illuminance · light level · ambient light](https://aethair.io/parameters/light/)

## Agriculture

### [Soil Temperature](https://aethair.io/parameters/soil_temperature/)

[°C · 1 device or option](https://aethair.io/parameters/soil_temperature/)

[Soil temperature.](https://aethair.io/parameters/soil_temperature/)

[Also: ground temperature](https://aethair.io/parameters/soil_temperature/)

### [Soil Moisture](https://aethair.io/parameters/soil_moisture/)

[% · 1 device or option](https://aethair.io/parameters/soil_moisture/)

[Soil moisture / water content.](https://aethair.io/parameters/soil_moisture/)

[Also: soil water content · volumetric water content](https://aethair.io/parameters/soil_moisture/)

### [Leaf Temperature](https://aethair.io/parameters/leaf_temperature/)

[°C · 1 device or option](https://aethair.io/parameters/leaf_temperature/)

[Leaf temperature (agricultural microclimate).](https://aethair.io/parameters/leaf_temperature/)

[Also: canopy temperature](https://aethair.io/parameters/leaf_temperature/)

### [Leaf Wetness](https://aethair.io/parameters/leaf_wetness/)

[— · 1 device or option](https://aethair.io/parameters/leaf_wetness/)

[Leaf wetness (disease/irrigation indicator).](https://aethair.io/parameters/leaf_wetness/)

[Also: leaf wetness sensor](https://aethair.io/parameters/leaf_wetness/)

## Analog / I/O

### [Analog Input (generic)](https://aethair.io/parameters/analog_input/)

[— · 3 devices & options](https://aethair.io/parameters/analog_input/)

[Generic analog input channel mapped at configuration time.](https://aethair.io/parameters/analog_input/)