The check name is EarthSoft.DQM.FieldBlankContamination. This check uses the following parameters:
•Multiplier – used in test to determine if result can be qualified as non-detect - defaults to 5 if no value supplied.
•Common_lab_multiplier – depends on CAS_RN – default multiplier is used if no value supplied.
•Flag_blank – if TRUE, the blanks are also qualified – defaults to TRUE.
Using a value for multiplier from RT_DQM_CONTROL_LIMITS is discussed in more detail here.
•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 in RT_DQM_CHECK_PARAM.
Associated results are found by:
1.Matching results (with detected concentrations only) by Method, Fraction, CAS_RN and FIELD_SDG. If matching samples are found, the process stops.
2.If no matching results are found in Step 1, results (with detected concentrations only) are matched by Method, Fraction, CAS_RN and CHAIN_OF_CUSTODY (COC).
There are three rules:
1.BLANK CONTAMINATION = Qualify the result in the blank sample if a concentration is detected and the FLAG_BLANK parameter = TRUE.
2.RESULT > BLANK * MULTIPLIER = Qualify an associated result if sample result > multiplier * concentration detected in the associated blank.
3.RESULT < BLANK * MULTIPLIER = Qualify an associated result if sample result < multiplier * concentration detected in the associated blank. Assuming the qualifier for this rule = “U”, then this will indicate the result is non-detect. When Completing an Event and saving qualifiers, there is also an option to set DETECTED_YN to "N" for all results with a "U" qualifier.
This check includes an internal unit conversion function, which allows blanks with units for liquids to be compared to results for soil samples. This internal function includes:
•ug/L to mg/kg
•ug/L to ug/kg
•mg/L to mg/kg
•mg/L to ug/kg
Any combination of units found in RT_UNIT_CONVERSION_FACTOR will also be used.
The following error occurs if the units differ and none of the above conversion factors apply:
Associated result (. . . . has units (. . . .) that do not convert to units of blank result (. . . .).
For this check to work, a record must be added to RT_UNIT_CONVERSION_FACTOR for that combination.
Copyright © 2020 EarthSoft, Inc • Modified: 25 Jun 2020