QA - Zero Span
--------------

Zero and Span are two different measurements that are quality control checks.

The zero check is a challenge of the instruments zero calibration conducted by introducing zero air into the analyzer and measuring the instrument response.

The span check is a challenge of the upper limit of the analyzers calibration conducted by introducing a calibration gas (approximately 80% of the operating range) into the analyzer.

Examples:

.. code-block:: text
   :caption: QA - Zero Span transaction in default mode

   

.. code-block:: text
   :caption: QA - Zero Span transaction in Tribal mode

   QA|I|Zero Span|905|TT|905|9009|42101|1|20200107|1|588|008|12|621|671||



Format
^^^^^^

.. list-table:: QA - Zero Span transaction format
   :widths: 1 5 15 4 3 1
   :header-rows: 1


   * - Seq.
     - Name
     - Description
     - Formatting Rules
     - Required
     - Key
   * - 1
     - `Action Indicator <Action%20Indicator%20for%20Transaction.html>`_
     - Indicator for Insert, Update, or Delete action.
     - Must = I, U, or D
     - Always
     - 
   * - 3
     - `Assessment Type <Assessment%20Type.html>`_
     - Indicates the specific QA assessment associated with the transaction.
     - Must = Zero Span
     - Always
     - Y
   * - 4
     - `Performing Agency <Performing%20Agency.html>`_
     - Agency Code of organization performing assessment.
     - Must exist in AGENCIES reference table.
     - Optional; defaults to user agency
     - 
   * - 5
     - `State Code / Tribal Indicator <State%20Code.html>`_
     - The FIPS state code of the monitor, or "TT" to indicate that the next field on the transaction is a Tribal code.
     - Must exist in STATES Reference Table or be 'TT' for Tribal Site
     - Always
     - Y
   * - 6
     - `County Code / Tribal Code <County%20Code.html>`_
     - The FIPS County Code of the site.  If the previous field on the transaction contains "TT", then the Tribal Code of the site.
     - Must exist in COUNTIES (for state) or TRIBAL_AREAS Reference table
     - Always
     - Y
   * - 7
     - `Site Number <Site%20Number.html>`_
     - Four digit number to uniquely identify site in county and/or tribe.
     - Must exist in SITES table with {State Code, county Code} or Tribal Code
     - Always
     - Y
   * - 8
     - `Parameter Code <Parameter%20Code.html>`_
     - The AQS parameter code assigned to the monitor in AQS.
     - Must exist in PARAMETERS reference table.
     - Always
     - Y
   * - 9
     - `POC <POC.html>`_
     - Parameter Occurrence Code:  One or two digit number identifying a specific monitor for a parameter at the site.  
     - Must exist in MONITOR table for non-Insert actions.
     - Always
     - Y
   * - 10
     - `Assessment Date <Assessment%20Date.html>`_
     - Date that the assessment was performed
     - YYYYMMDD.
     - Always
     - 
   * - 11
     - `Assessment Number <Assessment%20Number.html>`_
     - A unique number associated with an assessment performed at a site on a given day.  Value should be "1" unless additional same assessments are performed.  
     - Integer.
     - Always
     - 
   * - 12
     - `Monitor Method Code <Monitor%20Method%20Code.html>`_
     - The sampling methodology of the monitor being assessed.
     - Must exist in SAMPLING METHODOLOGIES reference table.
     - Insert
     - 
   * - 13
     - `Reported Unit <Reported%20Unit.html>`_
     - Units associated with the assessment concentrations  (Monitor  Concentration and Check Standard Concentration).
     - Must exist in UNITS reference table, and unit code must be for Concentration units type.
     - Unless Delete
     - 
   * - 14
     - `Monitor Zero Value <Monitor%20Zero%20Value.html>`_
     - The concentration value provided by the monitor being assessed when exposed to zero concentration.
     - Decimal.
     - Unless Delete
     - 
   * - 15
     - `Assessment Span Value <Assessment%20Span%20Value.html>`_
     - The known concentration of the calibration gas at the target span of the monitor.
     - Decimal.
     - Unless Delete
     - 
   * - 16
     - `Monitor Span Value <Monitor%20Span%20Value.html>`_
     - The concentration value provided by the monitor being assessed when exposed to the span concentration.
     - Decimal.
     - Unless Delete
     - 
   * - 17
     - `Null Data Reason Code <Null%20Data%20Reason%20Code.html>`_
     - A code to explain why no monitor value was reported.
     - Must exist in QUALIFIERS reference table.
     - Monitor values or null data code required
     - 
   * - 18
     - `Comment <Comment.html>`_
     - Free form text describing the assesment or invalidation.
     - Text, up to 2000 characters.
     - Optional
     -