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 Free Calibration Spreadsheet


Calibrations are the most important part of running a monitoring site.

These must be recorded correctly!

Here is the AQDM Calibration Spreadsheet that you can freely use and distribute

Most calibrations are performed following sound procedures. Sometimes these are just a simple zero and span while others take the time to record the diagnostic readings as well. Here is a short list of essential information that must be recorded at every calibration. This takes the guesswork out of the data processing often several months later.

Site name: use site names that are consistent and used by whoever visits the site

Start date: this is obvious

Start time: this shows when the ambient measurement finishes

End time: this shows when the ambient measurements restart

Zero and Span: these are your calibration measurements

Cylinder identification number: this is not always obvious when looking back at visits records

Cylinder pressure: this helps you judge when to replace the cylinder

Comments: this is your record of any unusual events or observations

Other information includes the instrument diagnostics. These can show the first sign of a problem and the duration. The diagnostics do not take long to record but can be difficult to interpret.

Here you can download the AQDM Calibration Spreadsheet. This is a simple Excel spreadsheet without any macros so is completely safe. Instruction are shown on the Start page in the box that says hover mouse here for instructions. Create a template for your site by simply deleting the pages for any unwanted instruments. You can always go back to the master template if you delete too much or need to add a new instrument. Values outside of the expected ranges are highlighted in red. This is something that paper forms can never do. Save the spreadsheet with a unique name that includes the site name and date. This will be much easier to retrieve than delving through a wodge of paper forms.

The opening page is for recording the essential information about the visit. Don't forget to record a comment if this a non-routine visit e.g. Visit to restore the power. Cells with a red dot in the top left have useful advice. Dates and times must be entered with the correct format so that Excel can recognise the data.

There are forms for all the common instruments. Values that are outside the expected range have highlighted in red. This simple alert allows you to check your typing or double check the instrument reading. Some values are just outside the expected range and are not a real problem. Other unexpected values can be the first sign of a fault which needs fixing as soon as possible. Paper forms cannot highlight out-of-range values.

Calibration zeros and spans are recorded in a standard and consistent form. There is advice shown that guides you through the data entry. This is where you need to enter the values in the correct box. Swapping zeros with spans or NOx with NO can make nonsense of your calibration. Cylinder details are important particularly the cylinder identification number. This can be difficult to read at every visit but you can always take the value from the last calibration spreadsheet. The cylinder pressure can show if the cylinder is nearly empty and when the cylinder was changed without anyone tell you!

Let me know if you find any mistakes or need a form for a new type of instrument.

Data ratification is so much easier if all the information is easily read - not handwritten, the numbers are recorded in the correct boxes, site operators are alerted to problems while on site and not months later, everyone uses the same site name, there is no doubt about which cylinder was used for the calibration and that it actually contained some gas.

Contact me Geoff.Broughton@aqdm.co.uk