UNI-T UT105 User Manual

Model UT105: OPERATING MANUAL
41
Measurement Operation(25)
To be adapted to the provisions for low injection and fuel
saving in the early period of the eighties, the computer-
controlled regulators were installed in the automobile
and the sensors provided the computer with some data
required. The multimeter is an effective tool for the
detection of the operation of a sensor.
1.Oxygen Sensor
The oxygen sensor is used to test the oxygen content in
the exhaust, giving rise to an appropriate voltage or
resistance. A low voltage (high resistance) means a too
high oxygen content in the exhaust, while a high voltage
(low resistance) means a too low oxygen content. The
computer regulates the ratio between the air and the fuel
according to the high or low voltage. There are normally
two types of oxygen sensors: the zirconia and titania sensors.
(Refer to the different external properties of the two types
for the details.)
Testing Procedure:
(1) Move the oxygen sensor out of the automobile.
(2) Set the rotary switch to 200 Ω . As prompted at the
LCD connect terminal, insert the red test lead into
the Ω terminal and the black one into the COM terminal.
(3) Connect the black test lead probe of the meter to the
ground terminal (i.e. cold end) of the sensor.
Warning:
l If the sensor has a 1- or 3-lead outlet, the ground
terminal is its shell.
l If the sensor has a 2- or 4-lead outlet, the ground
terminal is its special wiring.

UNI-T UT105 Specifications

General

Product type	Digital multimeter
AC voltage range	2 - 750 V
DC current range	0.2 - 10 A
DC voltage range	0.2 - 1000 V
Dimensions (WxDxH)	88 x 39 x 179 mm
Battery voltage	9 V

Weight and Dimensions

Weight	352 g