ETAS
Functional Description
ES430.1 - User’s Guide
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5
Functional Description
5.1
Broadband Lambda Sensor LSU
The broadband lambda sensor is a planar two-cell, marginal current sensor.
The combination of modular design and planar technology permits the integra
-
tion of several functions.
As the LSU sensor consists of a combination of a Nernst concentration cell
(sensor cell) and a pump cell transporting oxygen ions, it can carry out precise
measurements not only in the stoichiometric point at
= 1, but also in the lean
and rich ranges. Each sensor is calibrated individually.
The operational state of the lambda sensor LSU is characterized by the follow
-
ing parameters:
• R
i
(internal resistance of the lambda sensor)
• I
p
(pump current of the lambda sensor)
5.2
Operating Modes of the Measurement System
The measurement system consisting of ES430.1 and lambda sensor can either
be in a “Normal” operating mode or on “Standby”.
In the operating mode “Normal”, the ES430.1 is operated alone or in connection
with other modules of the ES400 family. The lambda sensor is connected to the
ES430.1 using a CBAL45x cable. When using a cable with an additional analog
output, a measure value is available additionally as an analog voltage signal at
the BNC socket of the sensor cable (see section 5.3.2 on page 34).
No measure values are available when it is “Off” or on “Standby”. The lambda
sensor can continue to be heated if necessary (see section 5.7 on page 38).