DQM Check for Relative Percent Difference - Field

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DQM Check for Relative Percent Difference - Field

Check for Relative Percent Difference (RPD) values for field duplicate sample results that fall outside Quality Control (QC) limits.

 

Notes:

It is important that RT_MATRIX.MEDIUM_CODE be populated for this check to work properly.

DT_RESULT_QC is not used for this check.

 

Check name is EarthSoft.DQM.RelativePercentDiffField = Field Duplicate RPD.

 

This check uses the reportable_result, result_type_code and test_batch_type parameters from Global Parameters. There are eleven other parameters:

Medium_code_soil – RT_MATRIX.MEDIUM_CODE for DT_SAMPLE.MATRIX_CODE for soil samples. Defaults to Soil.

Medium_code_water – RT_MATRIX.MEDIUM_CODE for DT_SAMPLE.MATRIX_CODE for water samples. Defaults to Water.

Multiplier – Multiplier used with detection limit in the FIELD DUPLICATE check to test for results with concentrations > multiplier * detection limit. Defaults to 5.

MultiplierSoil – Multiplier used with detection limit in the FIELD DUPLICATE check to test soil samples for results with an absolute difference in concentrations > multiplierSoil * detection limit. Defaults to 2.

Rpd_control_limit_other – RPD control limit for other samples. Defaults to 25.

Rpd_control_limit_soil – RPD control limit for soil samples. Defaults to 35.

Rpd_control_limit_water – RPD control limit for water samples. Defaults to 20.

Sample_type_Field_Dup – Defaults to FD.

Field_dup_detection_limit – Detection limit column to use in the Field RPD calculation (e.g. quantitation_limit or reporting_detection_limit). Defaults to first_non_null_value.

Compare_to_reported_field_dup - Y/N option to compare the calculated RPD to the reported RPD for Field Duplicate samples. Defaults to “N”.

Acceptable_variance_field_dup - acceptable variance when comparing the calculated RPD to the reported RPD for Field Duplicate samples. Defaults to “1”.

 

Additional Notes for Parameters:

If compare_to_reported = Y then:

1.DQM will compare the calculated RPD to the laboratory reported value in the qc_rpd column of field duplicate result

2.If the difference exceeds acceptable_variance, then DQM will create an error in the Errors tab.

 

Notes:

The default value is used if there is no record in RT_DQM_CHECK_PARAM for an input parameter.

The default value is used if the PARAM_VALUE is NULL for this parameter in RT_DQM_CHECK_PARAM.

 

There is one rule:

 

FIELD DUPLICATE =

Review results with DT_SAMPLE.SAMPLE_TYPE_CODE = sample_type_Field_Dup.

Find the parent sample using DT_SAMPLE.PARENT_SAMPLE_CODE or DT_FIELDQC_BATCH_PARTNER.

TEST #1:

·For both samples, is DT_RESULT.RESULT_NUMERIC >= multiplier * DT_RESULT.REPORTING_DETECTION_LIMIT?

·If TRUE, then

·Calculate rpd_dup.

oIf the MEDIUM_CODE of DT_SAMPLE.MATRIX_CODE = medium_code_soil, then rpd_cl = rpd_control_limit_soil.

oIf the MEDIUM_CODE of DT_SAMPLE.MATRIX_CODE = medium_code_water, then rpd_cl = rpd_control_limit_water,

oELSE rpd_cl = rpd_control_limit_other.

·If rpd_dup > rpd_cl, then qualify the results.

TEST #2 (if TEST #1 = FALSE):

·If the RT_MATRIX.MEDIUM_CODE of DT_SAMPLE.MATRIX_CODE = medium_code_soil,

·then AD_multiplier = multiplierSoil

·else AD_multiplier = 1.

·ABS_DIFF = absolute difference in the parent and duplicate concentrations = ABS(Parent - Dup).

·Detection_Limit = the value in the first column that is not NULL:

·DT_RESULT.REPORTING_DETECTION_LIMIT

·DT_RESULT.QUANTITATION_LIMIT

·DT_RESULT.METHOD_DETECTION_LIMIT

If the ABS_DIFF > AD_multiplier * Detection_Limit, then qualify the results.

 

Using control limits from RT_DQM_CONTROL_LIMITS is discussed in more detail here.