Valid calibration interval

Unfortunately, it is a big task for plant owners to report whether the plant’s AMS measurements are within the valid calibration interval, cf. EN 14181: 2014 (E) 6.5.

Save the hassle and let ReportLoq create the documentation for you.

If your system uses QAL2, the law requires that average values ​​(STAs) comply with the QAL2 report’s calibration interval. The purpose is to ensure that the system’s AMS measurements are a maximum of 10% outside the calibration interval used during QAL2. If NOx e.g. has a calibration range ranging from 0-450 mg / nm3, STA values ​​above 495 mg / nm3 would need to be recorded as being out of range.

Therefore, the QAL2 report specifies a calibration interval which must be entered in ReportLoq. The system subsequently checks for compliance with the calibration interval as described in MEL-16 and EN 14181 (E).

You can read more about the rules for calibration intervals in MEl-16. Section 10.1 paragraph 5 describes that:

  1. More than 5% of the AMS measurements (normalised values) are outside the valid calibration interval for more than 5 weeks during the period between two AST or AST and QAL 2, or
  2. More than 40% of the AMS (normalized) measurements are outside the valid calibration interval for one week.

ReportLoq provides the following tools for reporting compliance with the calibration interval, cf. this rule.

Report: QAL2 valid calibration interval

This report can be used to document whether the system has stayed within the calibration interval.

It contains a weekly statement of:

  • the number of valid intervals measured during operation
  • an estimate of the number of over how many of these were more than 10% outside the valid calibration range
  • a percentage weighting of exceedances for the week

The report is made on a yearly basis and thus gives a good overview of a long period of AMS measurements.

[pdf embed url = “ interval_year_2018-01-01.pdf”]

Example of report

Specific exceedances

In order to document compliance with MEL-16 section 10.1 paragraph 5a, it is necessary to take AST and QAL2 dates into account. If entered in ReportLoq, the automatic control will use this information to check after 5 weeks of AMS measurements with more than 5% measurements outside the calibration interval. In the event of such a situation, an exceedance is generated in ReportLoq which draws attention to the problem. 1 week with 40% is handled in the same way. This means that you will be actively notified of the problem if you have not seen it in the report.

The exceedances “5 weeks of 5%” and “1 week of 40%” can be included in exceedance reports for e.g. immediately reporting.

To make a long story short

It is important that the AMS measurements are within the calibration ranges if you want to make sure the measurements are correct. Let ReportLoq check automatically by entering the min and max calibration range only when creating QAL2.

ReportLoq takes care of all the control so you can spend your time on other important tasks.


Do you already have ReportLoq but are missing the report or are you just unsure how to interpret it? Or would you like to hear more about ReportLoq so you can evaluate if it is relevant for you? Contact us for a non-committal talk

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