Most of the following tools were developed by Dr Raymond J. Ritchie who has kindly allowed us to reproduce them here. The tools offer a range of calculating functions in the form of spreadsheets, and are largely self explanatory. Insert your parameter values and the calculator should do the rest. You may have to upgrade your software and download the Solver function. Feel free to download and use for your research. Our only stipulation is that these tools not be sold for commercial gain.
The Ritchie Carbonate Calculator calculates the concentration of CO2, HCO3-, and CO32- in natural waters or artificial media. Required inputs: pH, Temperature, Salinity, Current atmospheric CO2 (ppm), Total alkalinity.
Download Carbonate Calculator (56 KB)
The Ritchie Dilution Calculator determines the volume of Stock solution required to produce a volume of target solution. Required inputs: Concentration and volume of the Final solution required, and the concentration of the Stock solution. The Calculator also determines the concentration and volume of a Final solution created by mixing two solutions (with known concentrations and volumes) together.
Download Dilution Calculator (15 KB)
The Ritchie Irradiance Calculator calculates by interpolation the Photosynthetic Photon Flux Density (PPFD), UV-A and UV-B in units of micromols photons per metre squared per second, in increments of 15 minutes over the course of every day in a 365 day sequence. Calculations of irradiance in PPFD, UV-A and UV-B are also provided in units of mols per metre squared per day, and summed to provide mols per metre squared per annum.
Light Curve interpolator (for estimating light curve intensities from halogen-globe fluorometers)
Raymond J. Ritchie,
Faculty of Technology and Environment,
Prince of Songkla University-Phuket,
Kathu, Phuket 83120, Thailand
E mail: firstname.lastname@example.org,
FAX: +66 76 276 102,
Phone: +66 76 276 108.