From 472d70b6c9b37a963b15ce34bb79f2302f920a91 Mon Sep 17 00:00:00 2001 From: Jan Bouwhuis Date: Thu, 18 Sep 2025 15:36:12 +0200 Subject: [PATCH] Add comment on conversion factor for Carbon monoxide on dependency molecular weight (#152535) --- homeassistant/util/unit_conversion.py | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/homeassistant/util/unit_conversion.py b/homeassistant/util/unit_conversion.py index 75e515cd95c..be4372573f1 100644 --- a/homeassistant/util/unit_conversion.py +++ b/homeassistant/util/unit_conversion.py @@ -174,7 +174,9 @@ class CarbonMonoxideConcentrationConverter(BaseUnitConverter): UNIT_CLASS = "carbon_monoxide" _UNIT_CONVERSION: dict[str | None, float] = { CONCENTRATION_PARTS_PER_MILLION: 1, - CONCENTRATION_MILLIGRAMS_PER_CUBIC_METER: 1.145609, + # concentration (mg/m3) = 0.0409 x concentration (ppm) x molecular weight + # Carbon monoxide molecular weight: 28.01 g/mol + CONCENTRATION_MILLIGRAMS_PER_CUBIC_METER: 0.0409 * 28.01, } VALID_UNITS = { CONCENTRATION_PARTS_PER_MILLION,