Table 13. Summary of QC requirements for measurements with Hach ruggedized probes Minimum Frequency Acceptance Criteria Corrective Action QC Sample or Activity Four (4) prepared LDO 97-104% of theoretical DO samples analyzed prior Capability demonstration pH ± 0.1 of expected Repeat until acceptable. to any customer sample Others RPD < 25% analyses Not applicable. Results are Immediately before Calibration stability used to monitor stability of calibration measure Not applicable. monitoring probes and evaluate need for standards maintenance. After calibration, measure calibration Daily prior to sample standards (conductivity, pH, DO % Investigate and fix any obvious Calibration analysis and after every saturation of water saturated air) as problems. Repeat until 8 hours sample acceptable. pH ± 0.1 of expected, others 99-101% R Measurement of calibration standards or LCS (conductivity, pH, DO % saturation of LCS or of water saturated air) Investigate and fix any obvious Immediately following Calibration check Cond. 90-110% R, pH ± 0.1 of expected, problems. Recalibrate and calibration DO 97-104% sat repeat until acceptable. **LDO method requires LCS to be read in duplicate with each calib. event** Investigate problem. If system Field duplicate (duplicate precision is in control, qualify One (1) per sampling sample collected at one RPD < 25% results. If system precision is event of sampling sites out of control, reanalyze all sampling sites if possible. Samples and frequency 75-125% R Investigate all unacceptable Internal PE sample determined by Lab QA RPD < 25% results. Officer Samples and frequency determined by Investigate all unacceptable Blind PE sample Determined by PE provider accrediting agencies and results. projects
Table 13. Summary of QC requirements for measurements with Hach ruggedized probes QC Sample or Activity Minimum Frequency Acceptance Criteria Corrective Action Capability demonstration Four (4) prepared samples analyzed prior to any customer sample analyses LDO 97-104% of theoretical DO pH ± 0.1 of expected Others RPD < 25% Repeat until acceptable. Calibration stability monitoring Immediately before calibration measure standards Not applicable. Not applicable. Results are used to monitor stability of probes and evaluate need for maintenance. Calibration Daily prior to sample analysis and after every 8 hours After calibration, measure calibration standards (conductivity, pH, DO % saturation of water saturated air) as sample pH ± 0.1 of expected, others 99-101% R Investigate and fix any obvious problems. Repeat until acceptable. Calibration check Immediately following calibration Measurement of calibration standards or LCS (conductivity, pH, DO % saturation of LCS or of water saturated air) Cond. 90-110% R, pH ± 0.1 of expected, DO 97-104% sat **LDO method requires LCS to be read in duplicate with each calib. event** Investigate and fix any obvious problems. Recalibrate and repeat until acceptable. Field duplicate (duplicate sample collected at one of sampling sites One (1) per sampling event RPD < 25% Investigate problem. If system precision is in control, qualify results. If system precision is out of control, reanalyze all sampling sites if possible. Internal PE sample Samples and frequency determined by Lab QA Officer 75-125% R RPD < 25% Investigate all unacceptable results. Blind PE sample Samples and frequency determined by accrediting agencies and projects Determined by PE provider Investigate all unacceptable results.
Withers%20MST%20QAPP%2001072013.docx