Fluke 78 User Manual page 49

Turn off engine and insert test leads in the jacks shown.
1
Set rotary switch to volts dc. The meter defaults to the 40 V range.
2
3 Press the pushbutton 5 times to step to the 4 V range.
Connect the test leads to the sensor as shown. Start the engine. If the sensor
4
is unheated, fast-idle the car for a few minutes.
5
Press the pushbutton for 1 second to enter the MIN MAX mode. Let the engine
run for a few minutes to allow the meter to record enough readings.
Press the pushbutton to display the minimum reading; press again
to display the present reading; press again to display the maximum reading.
EXHAUST MANIFOLD
O
SIGNAL WIRE
4
CHASSIS
GROUND
HEATER WIRES
(LAMBDA) SENSOR
2
Figure 16. Using MIN MAX to Check an Oxygen Sensor
How to Store Minimum and Maximum Measurements
0
OFF
2
5
A
RPM
+
10A
30V
78
AUTOMOTIVE METER
DC
1 2 3 4
V
MAX
V Hz
V Hz
3
RPM
2 1
C F
PRESS
MIN / MAX 1 SEC
Hz
1 2 SEC
V
1
300V 30V
COM
CAT C F
FUSED
mt16f.eps
37