diff options
| -rw-r--r-- | api/current.xml | 11 | ||||
| -rw-r--r-- | core/java/android/hardware/Sensor.java | 7 | ||||
| -rw-r--r-- | core/java/android/hardware/SensorEvent.java | 60 |
3 files changed, 77 insertions, 1 deletions
diff --git a/api/current.xml b/api/current.xml index f524509..f76a216 100644 --- a/api/current.xml +++ b/api/current.xml @@ -77615,6 +77615,17 @@ visibility="public" > </field> +<field name="TYPE_RELATIVE_HUMIDITY" + type="int" + transient="false" + volatile="false" + value="12" + static="true" + final="true" + deprecated="not deprecated" + visibility="public" +> +</field> <field name="TYPE_ROTATION_VECTOR" type="int" transient="false" diff --git a/core/java/android/hardware/Sensor.java b/core/java/android/hardware/Sensor.java index f2b907b..595c7d1 100644 --- a/core/java/android/hardware/Sensor.java +++ b/core/java/android/hardware/Sensor.java @@ -97,6 +97,13 @@ public class Sensor { */ public static final int TYPE_ROTATION_VECTOR = 11; + /** + * A constant describing a relative humidity sensor type. + * See {@link android.hardware.SensorEvent SensorEvent} + * for more details. + */ + public static final int TYPE_RELATIVE_HUMIDITY = 12; + /** * A constant describing all sensor types. */ diff --git a/core/java/android/hardware/SensorEvent.java b/core/java/android/hardware/SensorEvent.java index 8c55bf3..4a7991f 100644 --- a/core/java/android/hardware/SensorEvent.java +++ b/core/java/android/hardware/SensorEvent.java @@ -304,7 +304,65 @@ public class SensorEvent { * in the clockwise direction (mathematically speaking, it should be * positive in the counter-clockwise direction). * </p> - * + * + * <h4>{@link android.hardware.Sensor#TYPE_RELATIVE_HUMIDITY + * Sensor.TYPE_RELATIVE_HUMIDITY}:</h4> + * <ul> + * <p> + * values[0]: Relative ambient air humidity in percent + * </p> + * </ul> + * <p> + * When relative ambient air humidity and ambient temperature are + * measured, the dew point and absolute humidity can be calculated. + * </p> + * <u>Dew Point</u> + * <p> + * The dew point is the temperature to which a given parcel of air must be + * cooled, at constant barometric pressure, for water vapor to condense + * into water. + * </p> + * <center><pre> + * ln(RH/100%) + m·t/(T<sub>n</sub>+t) + * t<sub>d</sub>(t,RH) = T<sub>n</sub> · ------------------------------ + * m - [ln(RH/100%) + m·t/(T<sub>n</sub>+t)] + * </pre></center> + * <dl> + * <dt>t<sub>d</sub></dt> <dd>dew point temperature in °C</dd> + * <dt>t</dt> <dd>actual temperature in °C</dd> + * <dt>RH</dt> <dd>actual relative humidity in %</dd> + * <dt>m</dt> <dd>17.62</dd> + * <dt>T<sub>n</sub></dt> <dd>243.12 °C</dd> + * </dl> + * <p>for example:</p> + * <pre class="prettyprint"> + * h = Math.log(rh / 100.0) + (17.62 * t) / (243.12 + t); + * td = 243.12 * h / (17.62 - h); + * </pre> + * <u>Absolute Humidity</u> + * <p> + * The absolute humidity is the mass of water vapor in a particular volume + * of dry air. The unit is g/m<sup>3</sup>. + * </p> + * <center><pre> + * RH/100%·A·exp(m·t/(T<sub>n</sub>+t)) + * d<sub>v</sub>(t,RH) = 216.7 · ------------------------- + * 273.15 + t + * </pre></center> + * <dl> + * <dt>d<sub>v</sub></dt> <dd>absolute humidity in g/m<sup>3</sup></dd> + * <dt>t</dt> <dd>actual temperature in °C</dd> + * <dt>RH</dt> <dd>actual relative humidity in %</dd> + * <dt>m</dt> <dd>17.62</dd> + * <dt>T<sub>n</sub></dt> <dd>243.12 °C</dd> + * <dt>A</dt> <dd>6.112 hPa</dd> + * </dl> + * <p>for example:</p> + * <pre class="prettyprint"> + * dv = 216.7 * + * (rh / 100.0 * 6.112 * Math.exp(17.62 * t / (243.12 + t)) / (273.15 + t)); + * </pre> + * * @see SensorEvent * @see GeomagneticField */ |