Relative Percent Difference III

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Relative Percent Difference III

Report Name: Relative Percent Difference III (93818)

previously called Relative Percent Difference_v3


Report Type: Standard


Description: The Relative Percent Difference III Report determines the difference between analytical results for up to three samples. This report can be used to compare sample results from different laboratories or locations. Users can select up to three different samples by selecting the SYS_SAMPLE_CODE for each.


The Date Range: The Start parameter requires input of the SAMPLE_DATE to populate the list of samples for user selection. The Sample information>SYS_SAMPLE_CODE section only lists SYS_SAMPLE_CODEs with SAMPLE_DATEs during the date indicated in Date>Start + one additional day.


The Report Tab compares the analytical results against the laboratory Practical Quantitation Limit (PQL) of the analyte(s) and any resulting 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.


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, and by default are:


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.



If the units of measurement for the primary, duplicate, and triplicate samples are different, select Unit(s) or Analyte\Analyte Group(s) to unify units (and ensure necessary unit conversion factor(s) is present).

The Relative Percent Difference Report involves multiple calculations; the processing time may take longer than expected. To avoid problems with delay, narrow the data input and/or extend the database connection timeout (see Timeout Error).


File Name: EarthSoft.Reports.Library.93818.dll


Language: English


Input Parameters: A selection that customizes the output of a report.


Input Parameters

Input Parameter Screenshot

Output Columns




Sample Information

Date Range


Sys Sample Code

Original Sys Sample Code (Required)

Duplicate Sys Sample Code (Required)

Triplicate Sample Type



Analyte Group(s)

Individual Analyte(s)




Delivery Group(s)

Reportable Result(s)

Detection Limit

Reporting Limit (Required)

Non-Detect Multiplier

Non-Detect Handling

Lower Limit (Required)

Upper Limit (Required)

Relative Percent Difference

RPD Lower Limit (Required)

RPD Upper Limit (Required)



Contact for more information




Database Type: SQL Server


Database Schema: Standard (no custom or add-on schema required)


Database Version: 6.4+


Data Requirements: Related primary and duplicate and/or triplicate sample, test, and result data; matching units and/or unit conversion factors present.


Report Requirements: Excel


Output Type: Excel, HTML


Example Output: View the example below.