The LA4 Lambda Meter is a high-precision measuring device for emission levels. It allows determining lambda values, oxygen content, and A/F ratio, as well as internal resistance, pump current, and heater voltage of the LSU lambda sensor. The LA4 permits exhaust gas measurements on gasoline, diesel, and gas engines. Based on the output signals from Bosch LSU broadband lambda probes, the measurement results can be calculated either by means of an analytical method that considers fuel properties and ambient conditions or by characteristic curves. The Lambda Meter LA4 is suited to both engine test bed use and in-vehicle deployment. It features a display, and may be used as a standalone unit or supply its data to INCA. The measured values can be continuously displayed on the built-in LCD. An additional display can be installed separately. A membrane keyboard allows quick and easy switching between the measured variables. Independently from the display, measured values can be transmitted to the PC or the ES5901/ES591 Interface Module via a serial SMB (V24) interface or to other devices via an analog output. The SMB interface is also used to daisy-chain LA4 modules.

After power-on, the device conducts a self-test using an internal reference. An optimized heater control ensures that the sensor quickly reaches its operating temperature while preventing overheating damages, even at highly fluctuating exhaust gas temperatures and different supply voltages.

Functions at a Glance

• Wide measurement range of  lambda, oxygen content and air/fuel ratio
• Fast measurement-readiness
• Rapid response of the measurement system to exhaust gas changes
• Derivation of emission values by characteristic curves or analytic calculation
• Membrane keyboard and built-in LCD – additional external  display available
• Analog output of measured values (configurable)
• Host connection via serial SMB (V24) interface