Adjustment to oxygen tension ideal for the fish
The ideal oxygen tension for fish at any given time depends on the temperature. Thus, it is not desirable to adjust for a fixed concentration in mg/l but for the ideal tension. What this means in practice is that the controller automatically adjusts the concentration in mg/l to suit the temperature. A figure of 100 is the ideal tension at a given temperature. Figures of 50 and 200 respectively are half and twice the numbers of milligrammes per litre required.
Indirect controlling of the oxygen tension at the outlet
Dr.Oxygen measures the oxygen tension at the outlet. A special PID regulation routine calculates a new SET point on the basis of the requirement at the outlet, and this controls the oxygen supply. The oxygen tension at the inlet is measured after the water has been aerated. This also means that natural changes in tension in the inlet water are immediately included optimally and utilized, with minimum oxygen consumption and minimum variations from the desired tension.
Control of an aerator
Dr.Oxygen has a relay terminal for controlling an aerator. The aerator is started when oxygenation is required.
Operation of pumps and supply of oxygen
Dr.Oxygen has relay terminals for two oxygen valves and two pumps, allowing partial loading and thus reducing energy consumption. Dr.Oxygen supplies oxygen "continuously variably" via time modulation with self-optimizing cycle times.
Dr.Oxygen can be set to give alarms at too high and too low IDEAL oxygen tensions and temperature levels in the inlet water.
There is a built-in clock which keeps going even in the event of power cuts. All data and control parameters are remembered.
Dr.Oxygen has built-in data logging with a facility for displaying "historic" data.
A battery-operated low-power model is available for logging data only.
Communicating with a personal computer
It is possible to connect Dr.Oxygen to a computer to transfer the logged information so it can be displayed graphical using Professor Partyline.
You're also able to control Dr.Oxygen from the computer. It can be part of a network with up to 32 units.