https://github.com/jimjeffers/aqi-calc

Perform Air Quality Index Calculations
https://github.com/jimjeffers/aqi-calc

Last synced: 3 months ago
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Perform Air Quality Index Calculations

• Host: GitHub
• URL: https://github.com/jimjeffers/aqi-calc
• Owner: jimjeffers
• License: mit
• Created: 2017-08-10T23:41:00.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2023-01-04T00:46:27.000Z (almost 2 years ago)
• Last Synced: 2024-07-03T19:49:56.934Z (4 months ago)
• Language: TypeScript
• Size: 722 KB
• Stars: 3
• Watchers: 2
• Forks: 0
• Open Issues: 12
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
AQI Calc

===

Easily convert pollutant measurements into AQI values per the [EPA's blue scale](https://forum.airnowtech.org/t/the-aqi-equation/169). For additional references on how

AQI is calculated see the thoughtful documentation on Wikipedia for [Computing the AQI](https://en.wikipedia.org/wiki/Air_quality_index#Computing_the_AQI). Also, for a complete

reference on all of the official break points view the official [EPA AQI Breakpoints page](https://aqs.epa.gov/aqsweb/documents/codetables/aqi_breakpoints.html).

Usage

-----

```js

import { AQSample, calculateAQI, Substance, TemperatureScale, Unit } from "aqi-calc"

const sample: AQSample = {

  substance: Substance.Ozone,

  unit: Unit.PPM,

  value: 0.055,

  temperature:{

    value: 25,

    scale: TemperatureScale.Celcius

  },

  interval: "8H"

}

console.log(calculateAQI(sample)) 

// => {aqi: 51, description: "Moderate", hexColor: "#ff0"}

```

Defining an Air Quality Sample:

-------------------------------

To convert a reading simply provide the input amount, the substance, 

and the unit the input amount represents. See the types below for

supported values:

```js

enum Substance {

  CarbonMonoxide = "CO",

  NitrousDioxide = "NO2",

  Ozone = "O3",

  SulfurDioxide = "SO2",

  FineParticles = "PM2_5",

  CoarseParticles = "PM10"

}

enum Unit {

  PPM = "PPM",

  PPB = "PPB",

  UG_M3 = "ug/m3"

}

enum Interval {

  OneHour = "1H",

  EightHour = "8H",

  Day = "24H"

}

interface ISample = {

  substance: Substance,

  interval: Interval,

  amount: number,

  unit: Unit,

  temperature?: ITemperature

}

```

Defining the Temperature:

-------------------------

The ambient temperature where the reading occured affects the air density and thus

the AQI calculations. If you do not know the temperature a default environment

assuming 25C will be used during any conversions.

```js

enum TemperatureScale {

  Farhenheit = "F",

  Celcius = "C"

}

interface ITemperature = {

  value: number,

  scale: TemperatureScale

}

```

Result Output:

--------------

The ouput of the calculateAQI method is returned as an `AQIResult` type which

defines the resulting AQI along with the corresponding description and hex color

for the matching break point:

```js

enum AirQualityDescription {

  Good = "Good",

  Moderate = "Moderate",

  Sensitive = "Unhealthy For Sensitive",

  Unhealthy = "Unhealthy",

  VeryUnhealthy = "Very Unhealthy",

  Hazardous = "Hazardous",

  None = "NONE"

}

type AQIResult = {

  aqi: number,

  description: AirQualityDescription,

  hexColor: string

}

```