ECM AFRecorder 4800 - Page 41

To compensate for differences in voltage references and ground potentials between the
AFRecorder and a data acquisition system receiving its outputs, use Equation A:
(
)
AFR AFR AFR
V
AFR=−×+
5
00
5
[Equation A]
where: AFR is the compensated AFR value.
AFR
0
is the programmed AFR for 0 Volts.
AFR
5
is the programmed AFR for 5 Volts.
V is the voltage calculated from Equation B.
Note that the “AFR” in Equation A is replaced by λ, φ, or %O
2
if those are the
chosen AFR units.
V
V
VV
VV
VV
ad
ad ad
ad ad
ad ad
=
−
+
−
−
3
41
4
41
4
1
[Equation B]
where: V is the value calculated and used in Equation A.
V
ad
is the voltage reported by the data acquisition system when collecting
data.
V
ad1
is the voltage reported by the data acquisition system when the
AFRecorder is outputting “1” Volt.
V
ad4
is the voltage reported by the data acquisition system when the
AFRecorder is outputting “4” Volts.
Note that V
ad1
and V
ad4
must be measured when the data acquisition system is
fully hooked-up and the AFRecorder is fully hooked-up and the AFR sensors
are “on”.
Simulated Exhaust Gas Oxygen (EGO) Sensor Outputs:
• Programmable transition Air-to-Fuel Ratio (in AFR, φ, or λ) for each AFR
sensor.
• "High" Output Level (for richer than programmed transition AFR):
Approximately 0.8 V., 20 mA max.
• "Low" Output Level (for leaner than programmed transition AFR):
Approximately 0.02 V.
• Transition Time (10% to 90% complete): Approximately .05 seconds.
• Update Rate: 0.01 seconds.
• Connector: See Analog Outputs Connector on page 36.
Specifications and Limits 37