Pyro Workbench

Upper Oxygen Calibration Point

Ambient Air
If ambient air is used as air calibration standard, there is no need for preparation. The dry oxygen sensor is simply exposed to the ambient air, optionally together with the dry external or optical temperature sensor. Wet sensors will cause undefined humidity levels around the sensors. And even worse, the evaporation of water drops would cool down the sensors causing undefined temperatures.

Air Saturated Water
Fill an appropriate amount of water into a flask (e.g. Duran flask) with a lid prepared with holes for inserting the oxygen sensor and a temperature sensor. Stream air through the water with an air stone connected to an air pump (available as commercial equipment for fish aquaria) for about 10 minutes. Alternatively, if no air pump is available, fill water into the flask leaving >50% air in the headspace, close it with a lid and shake the flask strongly for about 1 minute. Open the lid shortly for ventilating the headspace with fresh air. Close it again and shake the flask for 1 more minute. Insert the oxygen sensor and temperature sensor into the flask and ensure that the tips of the sensors are immersed in the water and free of air bubbles.

Air (100% RH)
Enclose wet cotton wool into a flask (e.g. DURAN flask) with a lid prepared with holes for the oxygen sensor and a temperature sensor from PyroScience. Typically, about 1/3 to 1/2 of the flask volume is filled with the wet cotton wool, while the other volume fraction is left free for inserting the tip of the oxygen sensor and optionally also the temperature sensor.

Custom (advanced)
Instead of air, a custom oxygen containing gas can be used for calibration. The necessary parameters (oxygen concentration, humidity and temperature) can be entered. The dry oxygen sensor is simply exposed to the custom calibration gas, optionally together with the dry external or optical temperature sensor. Wet sensors will cause undefined humidity levels around the sensors. And even worse, the evaporation of water drops would cool down the sensors causing undefined temperatures. For 100% humidity in your custom calibration gas, enclose wet cotton wool into a flask (e.g. DURAN flask) with a lid prepared with holes for the oxygen sensor and a temperature sensor from PyroScience and gas the flask with your custom calibration gas for a sufficient amount of time. Typically, about 1/3 to 1/2 of the flask volume is filled with the wet cotton wool, while the other volume fraction is left free for inserting the tip of the oxygen sensor and optionally also the temperature sensor.