.. auto-generated by script ../../../../utils/nxdl2rst.py from the NXDL source ../../../../base_classes/NXsensor.nxdl.xml

.. index::
    ! NXsensor (base class)
    ! sensor (base class)
    see: sensor (base class); NXsensor

.. _NXsensor:

========
NXsensor
========

**Status**:

  base class, extends :ref:`NXobject`, version 1.0

**Description**:

  This class describes a sensor used to monitor an external condition 
  - the condition itself is described in NXenvironment

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXgeometry`, :ref:`NXlog`, :ref:`NXorientation`

.. index:: NXgeometry (base class); used in base class, NXlog (base class); used in base class, NXorientation (base class); used in base class

**Structure**:

  .. index:: model (data field)

  **model**: :ref:`NX_CHAR <NX_CHAR>`

    Sensor identification code/model number

  .. index:: name (data field)

  **name**: :ref:`NX_CHAR <NX_CHAR>`

    Name for the sensor

  .. index:: short_name (data field)

  **short_name**: :ref:`NX_CHAR <NX_CHAR>`

    Short name of sensor used e.g. on monitor display program

  .. index:: attached_to (data field)

  **attached_to**: :ref:`NX_CHAR <NX_CHAR>`

    where sensor is attached to ("sample" | "can")

  .. index:: measurement (data field)

  **measurement**: :ref:`NX_CHAR <NX_CHAR>`

    name for measured signal

    Any of these values:

      * ``temperature``

      * ``pH``

      * ``magnetic_field``

      * ``electric_field``

      * ``conductivity``

      * ``resistance``

      * ``voltage``

      * ``pressure``

      * ``flow``

      * ``stress``

      * ``strain``

      * ``shear``

      * ``surface_pressure``


  .. index:: type (data field)

  **type**: :ref:`NX_CHAR <NX_CHAR>`

    The type of hardware used for the measurement.  
    Examples (suggestions but not restrictions):

    :Temperature:
      J | K | T | E | R | S | Pt100 | Rh/Fe
    :pH:
      Hg/Hg2Cl2 | Ag/AgCl | ISFET
    :Ion selective electrode:
      specify species; e.g. Ca2+
    :Magnetic field:
      Hall
    :Surface pressure:
      wilhelmy plate

  .. index:: run_control (data field)

  **run_control**: :ref:`NX_BOOLEAN <NX_BOOLEAN>`

    Is data collection controlled or synchronised to this quantity: 
    1=no, 0=to "value", 1=to "value_deriv1", etc.

  .. index:: high_trip_value (data field)

  **high_trip_value**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    Upper control bound of sensor reading if using run_control

  .. index:: low_trip_value (data field)

  **low_trip_value**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    Lower control bound of sensor reading if using run_control

  .. index:: value (data field)

  **value[n]**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    nominal setpoint or average value 
    - need [n] as may be a vector

  .. index:: value_deriv1 (data field)

  **value_deriv1[ref(value)]**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    Nominal/average first derivative of value 
    e.g. strain rate 
    - same dimensions as "value" (may be a vector)

  .. index:: value_deriv2 (data field)

  **value_deriv2[ref(value)]**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_ANY <NX_ANY>`}

    Nominal/average second derivative of value
    - same dimensions as "value" (may be a vector)

  .. index:: external_field_brief (data field)

  **external_field_brief**: :ref:`NX_CHAR <NX_CHAR>`


    Any of these values:

      * ``along beam``

      * ``across beam``

      * ``transverse``

      * ``solenoidal``

      * ``flow shear gradient``

      * ``flow vorticity``


  **geometry**: :ref:`NXgeometry`

    Defines the axes for logged vector quantities if they are not the global instrument axes

  **value_log**: :ref:`NXlog`

    Time history of sensor readings

  **value_deriv1_log**: :ref:`NXlog`

    Time history of first derivative of sensor readings

  **value_deriv2_log**: :ref:`NXlog`

    Time history of second derivative of sensor readings

  **external_field_full**: :ref:`NXorientation`

    For complex external fields not satisfied by External_field_brief

**Source**:
  Automatically generated from https://github.com/nexusformat/definitions/blob/master/base_classes/NXsensor.nxdl.xml