CompostManager Dissolved Oxygen Calculators
The Environment Agency are a UK regulator responsible for composting sites. They have recently released some technical guides to assist composters with the correct interpretation of oxygen readings taken from compost with a view to odour avoidance.
The CompostManager system is ideally suited to collecting and interpreting oxygen data from composting processes.
These calculators were developed by Eric Crouch © Soil & Land Consultants Ltd 2013 and are based on the spreadsheet calculations by Nick Sauer (Environment Agency) to accompany Odour Technical Guides 2 and 3.
Download the technical guides here:
Instant Online Calculator
There are two versions of the calculators which both give the same result: one online version to give instant results and one Excel add-in for processing larger volumes of data.
The Calculator is very simple to use.
Step 1 Enter the oxygen readings at the detector and compost temperature.
Step 2 Enter the detector temperature if known (this parameter is not too critical in most applications).
The calculator will automatically work out the corrected oxygen concentration and oxygen saturation concentration.
Microsoft Excel Add-in
This Add-in allows you to carry out dissolved oxygen calculations on Excel worksheets so large amounts of data can be processed instantly.
Here's a brief description of how to install and use the add-in (more detailed instructions to follow)
- Click on this link to download the add-in.
- When prompted, click 'save file' and save it somewhere on your computer. Chose the file location carefully as the file will need to remain in the same place for the add-in to work.
- Open up Microsoft Excel (2010 onwards)
- Click on the 'Developer' tab in the ribbon (if this is not visible, you'll need to right-click the ribbon and tick 'developer' in the ribbon options).
- Click on 'Add Ins' then 'Browse'.
- Locate the file you saved earlier then click on 'OK'. This should now load the add-in each time you open Excel
- The add-in contains two functions which correspond to the two technical guidance notes:
- RtnCorrectedO2(), which calculates oxygen concentrations corrected for volumetric effects; and
- RtnO2SatConcentration(), which calculates oxygen saturation concentrations from corrected oxygen levels and temperature.
- The easiest way to use the functions is via the function wizard: to do this, click the small fx symbol to the left of the cell contents bar
- Select 'Oxygen Calculation' from the category list
- The two functions are then visible, together with a description of each of the required input parameters.