Data Validation Of Continuous Analyzers
Data Validation Of Continuous Analyzers By Randy C. Turner, Technical Director, Swan Analytical USA
Introduction Continuous analyzers are routinely employed to monitor water and steam cycles in industries such as power generation, municipal water and waste water, pharmaceutical, and microelectronics. The chemists and operators rely on these analyzers to: • • • • • • •
Continuously monitor and or control the process Ensure quality control Control chemical feed Initiate boiler blowdown Automatically stop the process during excursions Alert operators of alarm conditions Maintain regulatory compliance
Continuous analyzers are an integral part of the process to maintain quality, ensure compliance, and protect the assets. Therefore it is imperative to ensure the analyzers are functioning properly and provide accurate and reliable data. This requires validation of the data provided by the analyzer on a routine basis. The frequency may be determined by the standard operating procedures (SOP) established by the organization or by federal and state regulatory agencies. Quality Assurance Off Line Quality Assurance Off line quality assurance or data validation involves periodic verification of the instrumentation by the operator or chemist. This involves: •
Procedures and methods used by instrument
•
Plant specific QA plan
•
Logging and monitoring of QA activities including maintenance activities
•
Performing maintenance as specified by the manufacturer
•
Verifying the analyzer −
With a known standard
−
Comparing to a verified portable or reference analyzer
Figure one illustrates portable analyzers used to monitor a process: − − −
Temporarily for trouble shooting Temporarily if the continuous analyzer is malfunctioning To validate the continuous analyzer data As seen in the Water Online (www.wateronline.com) newsletter.
Figure 1: Validation of Analyzer with Verified Portable Analyzer
On Line Quality Assurance – Self-Diagnostics On line or internal data validation by the analyzer provides significant value to the operator and chemist. This ensures the analyzer is performing properly and the data is accurate and reliable. This is especially valuable if the process is monitored remotely. Parameters that should be monitored to ensure the analyzer is performing properly and validate the data are: − − − −
Sample Flow Sample Temperature Reagent Level Status of Sensor
Self-diagnostics ensures the data is accurate and reliable and reduces the risk of “false truths” and “false alarms”. Validation data can and should be displayed and recorded along with the process value to ensure the operator and chemist the data is valid so they can make “good” decisions to maintain proper control of the process. Internal self-diagnostics and flow monitoring should be an integral part of the monitoring process and specified when purchasing continuous analyzers for process monitoring. Figure 2 illustrates the data validation self-diagnostics for each process value.
As seen in the Water Online (www.wateronline.com) newsletter.
28
Each Water Chemistry Process Value has an associated STATUS allowing • Fast identification of real versus false alarms • Detection of blind spots in monitoring (false truths) • Logging status information allows validation of process data logs • •
Measurement must not be used. Instrument requires immediate maintenance
STATUS UNCERTAIN Some conditions (e.g. sample flow) not in desired range or unknown Measured values on hold due to instrument maintenance
•
Measurement can no be trusted. Risk of “false truths” Instrument will require maintenance shortly
STATUS GOOD • Instrument in operation, no device error • All conditions required to ensure a valid measurement are fulfilled
•
STATUS BAD Instrument in operation with error message (e.g. lack of reagents) Maintenance required.
•
•
Measurement can be trusted. No risk of “false truths” Any related process alarm is really related to the process
Figure 2: Process Value Data Validation via Self-Diagnostics
Summary Quality assurance and data validation are critical components of a continuous process monitoring system to ensure accurate and reliable analysis results are provided. Developing an effective QA program and SOP along with employing continuous analyzers with integral flow monitoring and self-diagnostics ensures the data is accurate and reliable. This allows the operator and chemist to properly control the process, respond to excursions to maintain good control, avoid taking action due to erroneous data, and alert the operator when analyzer is malfunctioning. This reduces operating costs and avoids costly down time.
As seen in the Water Online (www.wateronline.com) newsletter.
Introduction Continuous analyzers are routinely employed to monitor water and steam cycles in industries such as power generation, municipal water and waste water, pharmaceutical, and microelectronics. The chemists and operators rely on these analyzers to: • • • • • • •
Continuously monitor and or control the process Ensure quality control Control chemical feed Initiate boiler blowdown Automatically stop the process during excursions Alert operators of alarm conditions Maintain regulatory compliance
Continuous analyzers are an integral part of the process to maintain quality, ensure compliance, and protect the assets. Therefore it is imperative to ensure the analyzers are functioning properly and provide accurate and reliable data. This requires validation of the data provided by the analyzer on a routine basis. The frequency may be determined by the standard operating procedures (SOP) established by the organization or by federal and state regulatory agencies. Quality Assurance Off Line Quality Assurance Off line quality assurance or data validation involves periodic verification of the instrumentation by the operator or chemist. This involves: •
Procedures and methods used by instrument
•
Plant specific QA plan
•
Logging and monitoring of QA activities including maintenance activities
•
Performing maintenance as specified by the manufacturer
•
Verifying the analyzer −
With a known standard
−
Comparing to a verified portable or reference analyzer
Figure one illustrates portable analyzers used to monitor a process: − − −
Temporarily for trouble shooting Temporarily if the continuous analyzer is malfunctioning To validate the continuous analyzer data As seen in the Water Online (www.wateronline.com) newsletter.
Figure 1: Validation of Analyzer with Verified Portable Analyzer
On Line Quality Assurance – Self-Diagnostics On line or internal data validation by the analyzer provides significant value to the operator and chemist. This ensures the analyzer is performing properly and the data is accurate and reliable. This is especially valuable if the process is monitored remotely. Parameters that should be monitored to ensure the analyzer is performing properly and validate the data are: − − − −
Sample Flow Sample Temperature Reagent Level Status of Sensor
Self-diagnostics ensures the data is accurate and reliable and reduces the risk of “false truths” and “false alarms”. Validation data can and should be displayed and recorded along with the process value to ensure the operator and chemist the data is valid so they can make “good” decisions to maintain proper control of the process. Internal self-diagnostics and flow monitoring should be an integral part of the monitoring process and specified when purchasing continuous analyzers for process monitoring. Figure 2 illustrates the data validation self-diagnostics for each process value.
As seen in the Water Online (www.wateronline.com) newsletter.
28
Each Water Chemistry Process Value has an associated STATUS allowing • Fast identification of real versus false alarms • Detection of blind spots in monitoring (false truths) • Logging status information allows validation of process data logs • •
Measurement must not be used. Instrument requires immediate maintenance
STATUS UNCERTAIN Some conditions (e.g. sample flow) not in desired range or unknown Measured values on hold due to instrument maintenance
•
Measurement can no be trusted. Risk of “false truths” Instrument will require maintenance shortly
STATUS GOOD • Instrument in operation, no device error • All conditions required to ensure a valid measurement are fulfilled
•
STATUS BAD Instrument in operation with error message (e.g. lack of reagents) Maintenance required.
•
•
Measurement can be trusted. No risk of “false truths” Any related process alarm is really related to the process
Figure 2: Process Value Data Validation via Self-Diagnostics
Summary Quality assurance and data validation are critical components of a continuous process monitoring system to ensure accurate and reliable analysis results are provided. Developing an effective QA program and SOP along with employing continuous analyzers with integral flow monitoring and self-diagnostics ensures the data is accurate and reliable. This allows the operator and chemist to properly control the process, respond to excursions to maintain good control, avoid taking action due to erroneous data, and alert the operator when analyzer is malfunctioning. This reduces operating costs and avoids costly down time.
As seen in the Water Online (www.wateronline.com) newsletter.
