Innovate Motorsports LM-1 Digital Air/Fuel Ratio (Lambda) Meter - Manual (Page 7)

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5. Calibration
There are two types of calibration for the LM-1: free air calibration and sensor heater calibration.
Sensor heater calibration is automatically performed the first time a new sensor is used, while
free air calibration should be executed frequently.
5.1. Free air calibration
To achieve maximum precision, the LM-1 and its sensor needs to be recalibrated frequently.
When the measured lambda is greater than 6, the display will show the oxygen content in %. For
free air it should show 20.9%. If the display value is different by more than 0.6%, recalibrate. You
can test the oxygen sensor by breathing on it. The oxygen content of your breath will show.
The sensor MUST be operated in free air for calibration.
If the wide-band sensor is installed in a vehicle, wait 6-8 hours after running the engine so that all
exhaust gas is dissipated from the exhaust tract of the vehicle. Better yet, disengage the oxygen
sensor and expose the sensor to air (away from the exhaust) for calibration purposes:
1. Connect the meter to 12V from the vehicle and switch it on.
2. After the sensor has warmed up, press the 'Calibrate' button for a minimum of 2 seconds.
3. After the calibration is complete, switch the LM-1 off and wait for 30 seconds before you start
the car.
The display will show "Free Air Calibr." while it calibrates itself. When the calibration procedure is
finished (2-3 seconds), the display returns to normal showing lambda and oxygen content. If the
oxygen content now differs from 20.9% by more than 0.6%, repeat the calibration.
5.2. Sensor heater calibration
If you change the sensor – either with a replacement sensor or a new type of sensor --, the
heater circuit of the LM-1 needs to be recalibrated as well. (See steps in chapter 3 'First Time
Use'). The heater calibration data in the LM-1 will be reset when the meter is operated from 12V
without a sensor connected for at least 5 seconds. You can force a reset by doing this, and then
recalibrate by turning the unit off, reconnecting the sensor, and turning the unit on.
After the sensor is warmed up the meter automatically calibrates the sensor heater controller to
the particular sensor. During this 20-second period the LM-1 collects and calculates sensor-
specific data required to quickly reach operating temperature in the future. During the heater
calibration the display will show:
Counting down to 0.
Note: When using the Bosch Sensors the LM-1 may perform multiple calibration passes. This is
normal and need not cause concern. When it completes, continue to a free air calibration. It is
recommended to perform a free air calibration after any time the sensor heater is
recalibrated.
5.3. Calibration Schedule