---
title: MTRCarbonMonoxideConcentrationMeasurementMeasurementUnit.PPB
framework: matter
role: symbol
role_heading: Case
path: matter/mtrcarbonmonoxideconcentrationmeasurementmeasurementunit/ppb
---

# MTRCarbonMonoxideConcentrationMeasurementMeasurementUnit.PPB

## Declaration

```swift
case PPB
```