LM-1: Digital Air/Fuel Ratio Meter

Tuning an engine for maximum power previously required long trial-and-error sessions on a dynamometer. With the LM-1, precise AFR measurement allows the user to correctly adjust many variables- including carburetor jetting, fuel injection, turbo fuel curves, etc.- without long and expensive dyno sessions. The meter’s digital signal processing technology provides data on exactly how rich or lean an engine is running at any load. The LM-1’s self-calibrating circuitry also compensates for changes in temperature, altitude, and sensor condition.

The instrument can sample and store the air-fuel-ratio and the other sensor data internally in operation for later analysis on a personal computer. At a sampling rate of 12 samples/second the instrument can store up to 44 minutes worth of data in non-volatile memory. The data can be downloaded to a personal computer using a standard serial port and viewed/analyzed by the included software or any standard spreadsheet program.

The standard LM-1 includes a Bosch wide-band oxygen sensor and cable, cigarette-lighter adapter, serial cable for PC connection, 9V battery, exhaust bung and plug, CD and manual. The LM-1 ships with a Bosch sensor, however, it can also function with other wide-band sensors, including Honda/NTK and VW sensors.

Available accessories include auxiliary input cables, alligator-clip power cable, exhaust clamp, analog output cable, and Aux. input expander. Additional accessories include a dash-mountable display and AC adapter.

The LM-1 sells for $349.99, including the oxygen sensor (Bosch LSU4.2), 10' sensor cable, 10' power cable, serial PC cable, and software.