Relative Percent Difference

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Relative Percent Difference

Report Name: Relative Percent Difference (example)

File Name: EarthSoft.Reports.Library.21339.dll

Dependencies: N/A

Software: EQuIS Professional and EQuIS Enterprise

Source: EQuIS Professional install

Language: English

Output Type: Excel1

 

Description: The Relative Percent Difference Report (RPD) determines the difference between analytical results reported in primary, duplicate, and triplicate samples.

 

Installation Instructions: This report assembly is part of the EQuIS Professional installation. No additional installation steps are necessary.

 

Overview:

Once these fields are populated, it is possible to run the report. The first step in this process is to choose the parameters. If any of the following fields are not populated correctly or if the location chosen in the report does not have duplicate or triplicates associated with the original sample, a “Report did not generate output” prompt will appear.

 

Note: Only values of DT_RESULT.REPORTABLE_RESULT “Yes” or "Y" are returned. Report Result Units and Sample Matrix must be selected for the report to run.

 

Once parameter selections have been made, click the GO button. The report output will be displayed in two separate tabs in Excel.

 

The Report Tab compares the analytical results against the laboratory Practical Quantitation Limit (PQL) of the analyte(s) and any result differences encountered in the primary, secondary and tertiary sampling.

 

The RPD is calculated as the absolute value of the difference between original and replicate samples divided by the average, and then expressed as a percentage or

 

Relative Percent Difference calculation equation: |(x2 - x1)|/((x2 + x1)/2).

 

The report checks the results for each analyte and determines if the analyte falls into a defined RPD control limit category. The RPD control limits can be defined by the report parameter selections (see chart below for default parameters).

 

Pass: RPD* is less than or equal to 30%.

Pass 1: RPD* is greater than 30% and the Analysis results are less than 10 times the limit of reporting (LOR).

Pass 2: RPD* is between 30% and 50% and the Analysis results are between 10 and 20 times the LOR.

 

*If the RPD exceeds the control limits, it is highlighted.

 

Report Requirements for DT_SAMPLE.SAMPLE_TYPE_CODE

Original Samples

Duplicate Samples

Triplicate

 

Tables: DT_FACILITY, DT_LOCATION, DT_RESULT, DT_SAMPLE, DT_TASK, RT_ANALYTE, RT_GROUP, RT_MATRIX"), RT_MTH_ANL_GROUP", RT_SAMPLE_TYPE

 

Report Parameters

lor option

Select the field used for lor: detection limit or quantitation limit.

non-detect handling

Select how non-detects are handled: eliminate non-detects or show all.

Location


Individual(s)

Parameter for selecting individual locations.

Group(s)

Parameter for selecting location groups.

Sample


Matrix(es)

Select one or more sample matrix.

Analyte(s)

Parameter for selecting individual analytes.

Units

Selection for analyte units.

Date Range

Section to select the sample start date and end date.

Delivery Group(s)

Parameter seletion for the delivery group.

Task(s)

Parameter selection for one or more task(s).

Non-detect multiplier

Indicate the non-detect multiplier. Default: 0.5

RPD lower limit

Indicate the lower limit of the relative percent difference standard. Default: 30

RPD upper limit

Indicate the upper limit of the relative percent difference standard. Default: 50

LOR multiple lower limit

Indicate the lower limit of the LOR multiplier standard. Default: 10

LOR multiple upper limit

Indicate the upper limit of the LOR multiplier standard. Default: 20

Sample type code for original sample

Select the SAMPLE_TYPE_CODE which indicates that this is the original sample.

Sample type code for duplicate sample

Select the SAMPLE_TYPE_CODE which indicates that this is a duplicate sample.

Sample type code for triplicate sample

Select the SAMPLE_TYPE_CODE which indicates that this is a triplicate sample.

 

1Excel report output requires a valid license of Microsoft Excel to view the output.