--- title: Sensor description: Instructions on how to setup your sensors with Home Assistant. ha_category: - Sensor ha_release: 0.7 ha_quality_scale: internal ha_domain: sensor ha_codeowners: - '@home-assistant/core' ha_integration_type: entity --- Sensors are a basic platform component in Home Assistant. They monitor the states and conditions of a variety of entities. An entity can be many things. This can include a physical device like a motion sensor that reports the battery level, a web service that retrieves the weather temperature, a built-in function that calculates the sun's elevation relative to your GPS position, or even a custom sensor you may have created to report the free space on your laptop. These are all _things_ reporting different types of information. Some of these sensors are built-in to Home Assistant, some are created automatically when you add an integration (see this [list](/integrations/#sensor)), and some can be created manually. The [Statistics](/integrations/statistics) and [Template](/integrations/template) sensors are two examples of the last case. ## Device Class The type of data a sensor returns impacts how it is displayed in the frontend. This is controlled by the sensor's device class designation. Built-in sensors and many created from an integration will have this designation predefined. Those can be modified in the [customize section](/docs/configuration/customizing-devices/). When manually creating a new sensor the device class may be optionally assigned. A full list of available sensor device classes is below: - **None**: Generic sensor. This is the default and doesn't need to be set. - **apparent_power**: Apparent power in VA. - **aqi**: Air Quality Index (unitless). - **atmospheric_pressure**: Atmospheric pressure in cbar, bar, hPa, inHg, kPa, mbar, Pa or psi - **battery**: Percentage of battery that is left in % - **carbon_dioxide**: Carbon Dioxide in CO2 (Smoke) in ppm - **carbon_monoxide**: Carbon Monoxide in CO (Gas CNG/LPG) in ppm - **current**: Current in A, mA - **data_rate**: Data rate in bit/s, kbit/s, Mbit/s, Gbit/s, B/s, kB/s, MB/s, GB/s, KiB/s, MiB/s or GiB/s - **data_size**: Data size in bit, kbit, Mbit, Gbit, B, kB, MB, GB, TB, PB, EB, ZB, YB, KiB, MiB, GiB, TiB, PiB, EiB, ZiB or YiB - **date**: Date string (ISO 8601) - **distance**: Generic distance in km, m, cm, mm, mi, yd, or in - **duration**: Duration in d, h, min, or s - **energy**: Energy in Wh, kWh, MWh, MJ, or GJ - **enum**: Has a limited set of (non-numeric) states - **frequency**: Frequency in Hz, kHz, MHz, or GHz - **gas**: Gasvolume in m³, ft³ or CCF - **humidity**: Percentage of humidity in the air in % - **illuminance**: The current light level in lx - **irradiance**: Irradiance in W/m² or BTU/(h⋅ft²) - **moisture**: Percentage of water in a substance in % - **monetary**: The monetary value ([ISO 4217](https://en.wikipedia.org/wiki/ISO_4217#Active_codes)) - **nitrogen_dioxide**: Concentration of Nitrogen Dioxide in µg/m³ - **nitrogen_monoxide**: Concentration of Nitrogen Monoxide in µg/m³ - **nitrous_oxide**: Concentration of Nitrous Oxide in µg/m³ - **ozone**: Concentration of Ozone in µg/m³ - **pm1**: Concentration of particulate matter less than 1 micrometer in µg/m³ - **pm25**: Concentration of particulate matter less than 2.5 micrometers in µg/m³ - **pm10**: Concentration of particulate matter less than 10 micrometers in µg/m³ - **power_factor**: Power factor (unitless), unit may be `None` or % - **power**: Power in W or kW - **precipitation**: Accumulated precipitation in cm, in or mm - **precipitation_intensity**: Precipitation intensity in in/d, in/h, mm/d or mm/h - **pressure**: Pressure in Pa, kPa, hPa, bar, cbar, mbar, mmHg, inHg or psi - **reactive_power**: Reactive power in var - **signal_strength**: Signal strength in dB or dBm - **sound_pressure**: Sound pressure in dB or dBA - **speed**: Generic speed in ft/s, in/d, in/h, km/h, kn, m/s, mph or mm/d - **sulphur_dioxide**: Concentration of sulphur dioxide in µg/m³ - **temperature**: Temperature in °C, °F or K - **timestamp**: Datetime object or timestamp string (ISO 8601) - **volatile_organic_compounds**: Concentration of volatile organic compounds in µg/m³ - **voltage**: Voltage in V, mV - **volume**: Generic volume in L, mL, gal, fl. oz., m³, ft³, or CCF - **water**: Water consumption in L, gal, m³, ft³, or CCF - **weight**: Generic mass in kg, g, mg, µg, oz, lb, or st - **wind_speed**: Wind speed in ft/s, km/h, kn, m/s, or mph

Example of various device class icons for sensors.