When using H2Blue, the accuracy and precision of your results will depend upon the care you take when performing the various steps involved in the titration. As outlined in the "Helpful Hints For Measuring" section, the most important considerations are:
• Run flow-through machines at least 20 seconds prior to collecting the test sample of H2 water
• Clean the graduated beaker each time before using
• Perform tests at as close to normal room temperature as possible, 72-77F (22-25C)
• Minimize splashing when filling the graduated beaker
• Measure the 6mL sample carefully, aligning the bottom of the meniscus to the 6mL line
• Holding bottle vertically, add drops in quick succession (counting them as you go), but without adding too many to avoid "passing" the titration endpoint
• Apply gentle, even pressure to the bottle when dispensing drops
• Stir the test sample gently with a stir wand-do not swirl or shake
• Be sure to count the last drop required to make the test sample remain pale blue
For best results, develop a consistent "testing style" during which you perform your H2Blue titrations the same way every time. By following the recommendations for testing, your margin of error should remain within the range of +- 12.5%.
Resolution, Accuracy, and Precision:
By design, H2Blue is able to resolve differences in H2 concentrations as small as *0.1 mg/L . Using advanced gas chromatography, H2 Sciences has recently conducted measurements of H2Blue up to 10 mg/L, where it was found to measure within 4% when measured using a calibrated gas standard. When titrations are done carefully, measurements using H2Blue are capable of producing both accurate (when measured against a calibration standard) and precise (repeatable) results. The following examples explain the difference between accuracy and precision:
* Techniques exist that can improve upon this resolution