This specification defines a concrete sensor interface to monitor
to measure the atmospheric pressure.
Status of this document
This is a public copy of the editors’ draft.
It is provided for discussion only and may change at any moment.
Its publication here does not imply endorsement of its contents by W3C.
Don’t cite this document other than as work in progress.
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The Barometric Sensor extends the Generic Sensor API [GENERIC-SENSOR] to provide information about the ambient atmospheric pressure, as detected by the
device’s primary barometric sensor.
The pressure level is reported in hPa (millibar) and represents the local atmospheric
pressure level, in contrast to many home barometers which are often adjusted to report
the pressure as was it at sea level as that is used in weather reports.
The Barometic Sensor has an associated abstract operation
to retrieve the sensor permission which
must simply return a permission whose name is "barometer".
The Barometic Sensor has an associated abstract operation
to construct a SensorReading object which creates a new BarometicSensorReading object and sets its pressure attribute to
positive infinity.
Pressure is a value that represents the the local atmospheric
pressure level. Its unit is the hPa (millibar).
The pressure attribute of the BarometricSensorReading interface represents the local atmospheric pressure level in hPa (millibar).
6. Acknowledgements
Tobie Langel for the work on Generic Sensor API and inputs on this specification.
Conformance
Document conventions
Conformance requirements are expressed with a combination of
descriptive assertions and RFC 2119 terminology. The key words “MUST”,
“MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”,
“RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this
document are to be interpreted as described in RFC 2119.
However, for readability, these words do not appear in all uppercase
letters in this specification.
All of the text of this specification is normative except sections
explicitly marked as non-normative, examples, and notes. [RFC2119]
Examples in this specification are introduced with the words “for example”
or are set apart from the normative text with class="example",
like this:
This is an example of an informative example.
Informative notes begin with the word “Note” and are set apart from the
normative text with class="note", like this:
Note, this is an informative note.
Conformant Algorithms
Requirements phrased in the imperative as part of algorithms (such as
"strip any leading space characters" or "return false and abort these
steps") are to be interpreted with the meaning of the key word ("must",
"should", "may", etc) used in introducing the algorithm.
Conformance requirements phrased as algorithms or specific steps can be
implemented in any manner, so long as the end result is equivalent. In
particular, the algorithms defined in this specification are intended to
be easy to understand and are not intended to be performant. Implementers
are encouraged to optimize.
Conformance Classes
A conformant user agent must implement all the requirements
listed in this specification that are applicable to user agents.
A conformant server must implement all the requirements listed
in this specification that are applicable to servers.