Oxygen analyzer MOA-2

The simplest example of using analyzers in diving is to measure the O2 content in a Nitrox or Trimix cylinder before diving.

The analysis is performed by approaching the sensor for a few seconds to the unscrewed valve next to the cylinder and reading the result on the display.

The valve should be unscrewed to a small extent, maintaining a constant flow of about 2-4 l / min and remembering that the pressurized mixture flowing out (and other rubbish from the bottle) should not damage the delicate cathode inside the sensor. Another solution is an additional plastic tee put on the valve or screwed into the cylinder valve (DIN), to which the sensor is connected (angularly) or a special flow restrictor guaranteeing a constant flow regardless of the gas pressure in the cylinder.

Before the analysis, it is always necessary to calibrate the analyzer, preferably on a cylinder with 100% O2, or if we do not have one in the field, calibrate it assuming that the atmospheric air at sea level is 20.9% O2.

Analyzers are delicate devices and must be protected against moisture, low and high temperatures and shock.

However, when the sensors themselves are not working, it is good to disconnect them from the analyzer and protect them with a special plug, then their lifetime can be up to 36 months.