Frequently Asked Questions

1. Why does the sample water sometimes turn "brown" when doing a test?

When using H
2Blue to measure water containing high levels of dissolved H2 (approx 4ppm or more), some "browning" of the 6mL sample may occur as drops are added. This is normal and is a result of the accumulation of the platinum catalyst, which does not get consumed during the reaction between H2Blue and the dissolved H2 gas . In order to determine the titration endpoint, watch for the sample to remain slightly blue.


2. Why does the 6mL sample change from "clear" back to "blue" after a few minutes?

As the sample is exposed to the air, the leucomethylene blue (clear form) oxidizes back to methylene blue (blue form)

3. Why does my dissolved hydrogen measure low, even though it contains a lot of visible gas bubbles? 

H2Blue detects only dissolved hydrogen gas, which is in the form of invisible nanobubbles. Water with high levels of visible gas may only indicate high levels of gas production, but low levels of dissolved gas. Many hydrogen machines include special infusion devices to encourage the gas to dissolve.

4. How accurate is H2Blue?

By design, H2Blue is able to resolve differences in H2 concentrations as small as 0.1mg/L. When done carefully, measurements using H2Blue are capable of producing both accurate (correct when compared to calibrated standard) and precise (repeatable) results. See the Accuracy vs Precision page for a detailed explanation.