Innovate Motorsports LM-1 Digital Air/Fuel Ratio (Lambda) Meter - Manual (Page 6)

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The maximum temperature of the sensor at the bung (the sensor hexagon)
should not exceed 500 o C or 900 o F. If these temperatures are exceeded in your
application you should either install a copper heat sink (instructions below) or the
Innovate Motorsports Heat-Sink Bung extender (HBX-1).
The bung extender is recommended for situations where airflow is restricted or
the encountered heat is higher than a heat sink can handle.
3.2. How to fabricate a copper heat sink
Use a 4” x 4” (10cm x 10 cm) sheet of copper sheet metal 14ga (1.5mm) thick. Drill a hole in the
center with the same diameter of the oxygen sensor threads ~3/4” (19mm).
Fold the sides up 45 deg and mount it between the sensor and the bung like you would a big
washer. Orient it such that the sides are exposed to good airflow.
4. Operation
Once the LM-1 has been installed and is in place (see Chapter 4: Installation), lambda
measurements can now be taken.
In operation, the meter's display shows:
showing both the current lambda value and air-fuel-ratio. The numeric lambda and air-fuel-ratio
values are averaged over about 0.2-0.3 seconds so that the numbers are more consistent and
easy to read.
If lambda is greater than 6 (for example, in free air), the display will show “—“ for Lambda, and
instead of an AFR reading, the percent of oxygen will be shown..
The bar-graph at the bottom shows the actual instant lambda value in 16 steps. The more of the
bar showing, the richer the mixture. The bar at mid-level means a lambda value of 1.0 (AFR of
14.7 for gasoline engines). If the whole bar shows, the actual lambda value is 0.68 or richer (AFR
of 10 or less for gasoline engines). If none of the bar shows the lambda value is 1.32 or leaner
(AFR 19.4 or more for gasoline engines).