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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 |
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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 |
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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. |
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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. |
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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.
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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.
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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!
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Let me know if you find any mistakes or need a form for a new
type of instrument. |
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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. |
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Contact me Geoff.Broughton@aqdm.co.uk |
