Learn how to set up a Flow Meter Calibration Worksheet with Measurement Uncertainty in 7 simple steps using Metquay!

Even in this era of cutting edge technology, most of the ISO/IEC 17025 accredited calibration and testing labs across the globe rely on excel sheets to calculate measurement uncertainty and calibration certificate preparation. Needless to say, as time moves on the entire process would become cumbersome and error-prone.

One of the primary reasons for labs to choose excel sheets to manage their measurement uncertainty over calibration management software is the flexibility excel sheets provide in managing the formulae. You do not need programming knowledge or should depend on the software vendor to modify the software to meet the changing requirements as suggested by the auditor or the ISO 17025 standards from time to time.

However, as time progresses and scope expands these excel sheets become one of the biggest bottlenecks in your calibration business. It’s a double whammy! the time you spend on audits and ISO 17025 compliance, Calibration Jobs, Quality Assurance etc goes up and it would be an uphill battle to remain profitable without compromising on quality.

The foundation stone of Metquay – Calibration, Testing & Asset Management Solution is laid on the idea of giving more power to its users by giving them all tools they need to set up their own Calibration Worksheets with measurement uncertainties without having to depend on a programmer. In addition, we encapsulated this feature around the concepts of ISO/IEC 17025 so that our customers could increase productivity without compromising on quality or compliance. All workflows in Metquay are carefully validated against the ISO 17025 checklist to ensure cent per cent conformity.

To help you understand the concept better, here is a 7 step procedure to set up a Flowmeter calibration with measurement uncertainty paired with an automated calibration report.

Step 1: From Metquay’s Worksheet Menu, Add a new worksheet with the name “Flow Meter” & type “Instrument”. Metquay will generate a new Calibration Worksheet for you to get started.

Step 2: Add two Sections in the worksheet with the following names(you could follow your own naming conventions)

  • Parameters
  • Readings 

Step 3: Inside the section named Parameters add the following Form Fields 

  1. No: Cal Points [ this field will allow the user to input the number of Cal points to be generated on each calibration job]

  2. No: Repeats[ this field will allow the user to input the number of repeat measurements to be captured]

  3. Reference Instrument Used [This would be a drop-down to choose the appropriate reference instrument. Each reference instrument will be associated with a similar worksheet which would contain its latest calibration data and measurement traceability as per ISO 17025 guidelines]

  4. Sensor Range [this would be the range of the reference instrument used ]

  5. Flow Meter Range [ range of the flowmeter under calibration]

  6. Unit [choose the field type ‘combo’ and select ‘flow’; this would populate all the standard flow units]

For each field added to the calibration worksheet, you would have an associated set of options to configure its behaviour. For example, the sensor range field is a numeric field which is populated with the range of the master equipment used. 

Each field would have a variable associated with it which could be used to write expressions 

Step 4: Inside the section ‘Reading’, add the following Table Fields [this is where we are going to capture the calibration raw data and the table structure will help us capture the data and aggregate it efficiently].

Also as the Table Row Expression give the variable for No: Cal points from the Parameter section.

  1. Resolution
  2. Unit 
  3. Reference Flow Rate
  4. Test Reading [ choose type as Repeat and inside the expression give the variable of the field No: Repeats from the Parameter Section]  
  5. Temperature of water in Degree Celsius
  6. Mean Reading
  7. Standard Deviation 
  8. Standard Uncertainty (%)
  9. Degrees of Freedom
  10. KT Distribution
  11. Uncertainty of Master(UB1)
  12. Accuracy of Master(UB2)
  13. Resolution of UUC(UB3)
  14. Uncertainty of Repeatability(UB4)
  15. Uncertainty of Installation error ( UB5)
  16. Combined Uncertainty(Uc)
  17. Expanded Uncertainty(Ue)

Step 5: For each field added under the section Reading, write appropriate expressions using the variables generated for each field. Also, make sure to check the ‘Show in Certificate’ option for those fields that need to be shown on the final calibration certificate.

Here are a few examples 

  1. Mean Reading:  the expression would be RowAverage(Flowmeter_Reading_TR_Test) ; 

Here Flowmeter_Reading_TR_Test is the variable for the field Test Reading which we configured as a repeat field.

  1. Standard Deviation : RowStdDev(Flowmeter_Reading_TR_Test)
  2. Combined Uncertainty : 

SquareRootOfSumOfSquares(Flowmeter_Reading_T_StandardUncertainty,

Flowmeter_Reading_T_UncertaintyofMaster,

Flowmeter_Reading_T_AccuracyofMaster,

Flowmeter_Reading_T_ResolutionofUUC,

Flowmeter_Reading_T_UncertaintyofRepeatibility,

Flowmeter_Reading_T_UncertaintyofInstallationError)

Once you write the expression and hit Verify, the expression engine in Metquay will validate the expression and throw errors if any. 

Step 6: Save the worksheet and hit Preview. You would get a preview of the worksheet you have created with all the fields. 

Enter some sample values and validate your formulae( you may do this in-between adding a few sets of fields in case of a more complex worksheet)

Step 7:  Hit the Preview Certificate option to view how the data would appear in the calibration certificate. You could do the fine adjustments, hide/ re-arrange the order of fields, give grouping headers, section headers etc for better presentation.

Now your worksheet is ready, associate this with jobs and generate calibration certificates with data points and measurement uncertainties with ease.

We have only touched the tip of the iceberg here. The functionalities that Metquay worksheets provide to a technician for raw data capture, processing, uncertainty calculations and calibration certificate preparations in virtually unlimited. 

Please stay subscribed to Metquay Blog for more articles and videos on calibration worksheet preparation, Calibration Certificates, Setting up measurement Uncertainty, Generating Graphs and charts from your calibration raw data, CMC corrections etc.

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