If the sensor is dirty or has not been polarized for a sufficient period of time, it may lead to increased noise, slow response, and decreased sensitivity.  

Before calibrating and using the sensor, it should be polarized overnight.  The longer the polarization time, the more stable and reproducible will be the response of the sensor. Polarize the sensor by connecting it to the SensoReady or to the inNO system while immersed in water. 

If the sensor tip is dirty, clean it by one of the following methods:

1.  Immerse in a protease solution
2.  Immerse in a strong acid (3-5 M)
3.  Dip in boiling water
4.  Wipe with an ethanol or acetone soaked cotton swab