When we first began 7 years ago, there were no standards for measuring HHO gas production from a generator (still are no standards today). There were various methods tried from plastic bottles in a bucket of water, to gas/air flow meters, to highly expensive hydrogen meters that no one could afford. One mfg used such a complicated method of measurement, that no one would ever be able to compare test results (he claimed his was absolutely the most efficient units on the market). Ridiculous.
The upside down plastic bottle in a tank of water was and is most commonly used, but is not accurate and can have so many variables as to make it unreliable. One bottle may be ultra thin and light, another may be a heavier mil thickness, skewing the results. Since the measurement is based on timing, the start and stop times can be off by a few seconds either way, also skewing the results.
But the biggest problem in measuring the accurate production of HHO gas from a generator, is quite frankly, fraud and lying, not the measurement technique.We used these types of gas/airflow meters instead of the bottles, as we felt they were more accurate. The argument in using these is that the heat and steam produced by an hho generator can also skew the results.
I cannot emphasize enough how MOST companies selling hho kits online, FAKE their results. That's why we quit even publishing them - whats the point if everyone is just lying about it? How do they Fake the numbers? Easy. They know you are not paying attention, so here is what most do:They Crank Up amperage/voltage Way higher than normal for short videos.They Don't show amp gauge/voltage meter at same time as gas production.They zoom in close to bubbles and turn up current out of sight of camera. They have NO PROOF and NO VIDEOS of production - so they just make up numbers.