Oxygen signal not responding
From Bioblast
Problems
- The oxygen signal remains at or close to zero even at high oxygen levels.
- The signal at air saturation is abnormally low.
Test and Solutions
Option 1: The oxygen signal is very low at air saturation and less responsive than expected.
- Solution 1.1: Check the gain setting for the oxygen.
- The gain setting was too low, and the oxygen signal increases to the expected level after increasing the gain.
- The gain was correct [continue with Solution 1.2].
- Solution 1.2: Disconnect the polarographic oxygen sensor by unscrewing the sensor head from the sensor connection.
- The signal (electronic zero without connection to the sensor head) is close to zero, but increases when connecting the central pin and the thread with the tip of a finger. This indicates that the problem resides in the POS sensor head but not in the electronics.
- Follow the instructions for oxygen sensor service MiPNet08.04. In particular, check if electrolyte has been added below the membrane, or if inadvertedly more than one membrane covers the sensor. In addition, check the gain for the sensor signal. If all service precautions fail to solve the problem, the polarographic oxygen sensor (POS) has to be sent to us for further service, or a new sensor is to be applied.
Option 2: The signal does not respond to short-circuiting by the finger tip.
- Solution 2: Disconnect the other oxygen sensor from the sensor connector and exchange the cables between right and left sides of the Oxygraph-2k.
- The signal does respond with the other sensor connector, and the problem has "moved" to the other side with the POS connector. This indicates location of the problem in the sensor connector. The defective sensor connector has to be sent to us for electronic service or exchange for a new sensor connector.
- The signal remains non-responsive on the previously defective side, and the problem did not "move" with the sensor cable to the other side. This indicates an electronic problem on the main unit of the Oxygraph-2k. Your instrument would have to be sent to us for electronic service. In this less favourable case, you should send the Oxygraph-2k, sensor connectors and sensor heads (dry, without electrolyte). The glass chambers should be removed before packing, and the original packing box (Box 1)should be used for shipment.
