Motec LTC, Руководство пользователя

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16 Introduction
Calibration
Warning: The Bosch LSU 4.9 Lambda sensors are fitted from factory with a
calibrated trimming resistor embedded in the sensor connector, if the factory
sensor connector is cut off and replaced with another type the LTC will not
operate correctly.
Note: Unlike the Bosch LSU 4.9 the NTK sensors standard connector can be
removed and replaced by a non-standard connector without affecting the
performance of the sensor or the LTC-NTK. However, the initial factory
calibration method will not work as the calibration resistor is built into the
original connector. In this case Free Air calibration is required. It is
recommended that no wiring modification is made to the NTK sensor or LTC-
NTK unless completely necessary.
Calibration Methods
Initial factory calibration
The default calibration method uses the known characteristics of a new
sensor that has been factory trimmed.
Free Air Calibration
As a sensor ages, the sensor calibration may change. To maintain accurate
readings, the LTC allows for re-calibration using the known oxygen
concentration of free air. The free air calibration procedure takes several
readings with the sensor in free air to calculate new calibration values.
To perform an accurate free air calibration, the lambda sensor must be
removed from the exhaust and placed in an open air environment.
It is recommended to perform the calibration outside of a workshop or dyno
room as there may be large amounts of hydrocarbons in the atmosphere.
Contaminated air will result in an incorrect calibration or a failure to
calibrate. Wind should also be avoided as it can affect the free air
calibration.
Reference Gas Calibration (LTC-NTK only)
Reference gas samples for different lambda can be purchased (not
available from MoTeC) for use as a means of calibrating the LTC-NTK.
This method is provided for but is unlikely to be implemented by most
users.
Calibrate the LTC 4.9 Unit
•
Click Calibrate… to open the Gain Calibration window