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Reflections from 2018 Year End Reporting – Part 3: Temperature Monitoring Impacts on Data Validity

Posted: February 21st, 2019

Authors: Matt C. 

Welcome to the third of a five-part blog series hosted by ALL4’s Continuous Monitoring Systems (CMS) Practice Area that looks back at some of the key points of discussion that came up while completing reports for the second half and fourth quarter of 2018 reporting periods.  In Part 3, we take a quick look at how, or if, the status of temperature monitoring systems affects CMS data.  Be sure to check out Part 1: Validation Sequence Impact on Data Validity and Part 2: Ancillary Analyzer Impacts on Data Validity.

CMS have their own monitoring components that function as self-checks to ensure the “health”, or representativeness and accuracy of the data being collected.  Examples of this are temperature monitoring components, typically thermocouples, often installed to monitor the temperature of sample lines and sampling equipment associated with the CMS.  The temperature of these sampling components is monitored to ensure that the components are adequately heated to remove moisture or prevent condensation in a sample.  Although the temperature monitoring systems are a component of the CMS used to indicate if there is an issue with sampling equipment, their outputs do not necessarily impact data validity, but can cause data to be suspect or require additional scrutiny.  Therefore, if a temperature monitor shows a fault status, or if a temperature monitor is not responsive on a certain day, CMS data for associated CMS is suspect and will require additional scrutiny.  The fault status or failed calibration serves as an indication to inspect and potentially service a component of the CMS; however, the validity of the CMS data associated with it is not affected.

Note that although this blog focuses on sample system temperature monitoring, stack temperature monitors are also utilized by facilities to convert actual volumetric flowrates to standard volumetric flowrates.  Similar to sampling temperature monitoring systems, if a stack temperature monitor shows a fault status or alarm, the stack temperature data and any subsequent CMS data dependent on stack temperature would be suspect and require additional scrutiny.

Due to the recent polar vortex we experienced across the country, the low temperatures triggered setpoint alarms in temperature monitoring systems that many of our clients did not even know existed.  These setpoint alarms may have caused invalid data to be logged by the data acquisition and handling system (DAHS).  Although the DAHS tagged the data as invalid, the data collected during the alarming period was representative and in-control with respect to ongoing quality assurance activities; therefore, valid for use in compliance demonstrations.  In some cases the temperature monitoring system setpoints were adjusted or the data validity status was revised to tag data as suspect for review but not automatically invalidating data.  If you have questions about temperature monitors and their impact on CMS data validity at your facility, or any other aspects of CMS, please reach out to me.  I can be reached at 610.933.5246 extension 139, or at mcarideo@all4inc.com.

Don’t forget to look for Part 4 this five-part blog series next week on DAHS upgrades and how they should be proactively managed. To ensure that you do not miss out on the action, signup below for our 4 The Record articles.


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