MoTeC PLM - Manual (Page 9)

MoTeC Meter Operation 9
Exhaust slip joints should be avoided near sensor placement as some designs
allow air to enter. Slip joints can be reversed to make them better for use near
sensors.
Sensor Warm-up
The internal heater in the LSU or NTK sensor is powerful enough to allow
accurate measurement when gas temperature is at room temperature. The
Bosch LSU will take ~20seconds to heat up, while the NTK ~30 seconds before
reading.
The maximum continuous operating temperature of the sensors is 850 degrees,
and sensors should not be used for a prolonged period at temperatures higher
than this. The sensor can be heated to 930 degrees for a short period (not
exceeding 10 minutes), but the accuracy may be reduced.
Sensor Lifetime
The sensor life time is dependant on the type of fuel being used and the volume
of gas flow over the sensor. The sensor can also be contaminated by exhaust
manifold sealants, so Exhaust Gas Sensor friendly sealants should be used.
Leaded fuel will reduce the sensor lifetime substantially due to lead
contamination of the sensor element. Typically, for high performance engines
the sensor should last at least 500 Hrs in unleaded fuel and 50 Hrs in leaded
fuel. Longer lifetimes can be expected for less demanding applications.
Exhaust slip joint design to avoid incorrect lambda readings
Exhaust flow
Introduced air No air introduced