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. Under these conditions, watch for the sample to remain slightly blue in order to determine the titration endpoint.


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

As the sample is exposed to oxygen in 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. While water with a lot of visible gas bubbles may indicate high levels of H2 gas production, it can contain relatively 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.

Frequently Asked Questions