I know this has been asked a lot and I did search but I could not find a definite answer. To calibrate the LC-1 to free air I must ground the calibration wire (the black one) for 3 seconds. I have the indicator LED hooked up between the black wire and the ground. Well during this three seconds where it's grounded the LED will flash. In the manual it says that the LED should be off during the calibration? Am I doing something wrong? Also the sensor is still reading wrong after I do this.