Measuring H2 and O2 Concentrations in Electrolysis Gas Streams

Hello everyone,
I’m a researcher in Ohio. I have a water electrolysis test setup generating high-purity hydrogen and oxygen. I’m looking into sensors to measure the concentration of H2 and O2 in these gas streams.
I noticed that ATO sells both hydrogen and oxygen fixed gas detectors (SKU: GD300-H2 and GD300-O2). The specs appear to meet our requirements in terms of resolution and LDL, but I have a few concerns.
1. These sensors look like they’re designed for ambient gas detection—can they be adapted for flow-through measurement (e.g., using a tee fitting)?
2. If so, is there a recommended flow rate we should maintain?
3. What pressure range do these sensors tolerate?
Any insights or prior experience with similar setups would be greatly appreciated!

Hello everyone,
I’m a researcher in Ohio. I have a water electrolysis test setup generating high-purity hydrogen and oxygen. I’m looking into sensors to measure the concentration of H2 and O2 in these gas streams.
I noticed that ATO sells both hydrogen and oxygen fixed gas detectors (SKU: GD300-H2 and GD300-O2). The specs appear to meet our requirements in terms of resolution and LDL, but I have a few concerns.
1. These sensors look like they’re designed for ambient gas detection—can they be adapted for flow-through measurement (e.g., using a tee fitting)?
2. If so, is there a recommended flow rate we should maintain?
3. What pressure range do these sensors tolerate?
Any insights or prior experience with similar setups would be greatly appreciated!Hello,
Just to clarify a few things:
GD300-H2 and GD300-O2 are only designed for gas (not water or liquid environments).
They require a constant flow of 1 L/min to function properly.
They must be operated at a pressure of 1 bar ±10%.
They can measure both ambient concentrations and pipeline concentrations, but only under the above flow and pressure conditions.
So yes, you could run your gas through them, but only if you can meet those requirements.

Thanks for the information!
The streams will be entirely gas, but the flow is variable depending on the current we are applying. If we have to hold at least 1 L/min, then these sensors won’t work for our system since the flow ranges from ~75 mL/min to 900 mL/min.
Thank you for your time!