CEM DT-9995 Instruction Manual

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AUTOMOTIVE MULTIMETER

WITH PC INTERFACE

INSTRUCTION MANUAL

Contents

Introduction……………………………………………………………………….1
Safety………………………………………………………… …………………… 2
Getting Started…………………………………………………………………6

Meter Basics…………………………………………………………………………7
Digital and Analog display…………………………………………………………8
Function and Range Select…………………………………………………………9

Push-button Functions……………………………………………………10

Mode Button… ……… …… …… …… …… …… …… …… …… …… 10
Range Select Button…………………………………………………………10
Range Exit ……………………………………………………………………10
+ TRIG Button………………………………………………………………10
Data Hold /Backlight Button………………………………………………12
MAX/MIN/RS232 Button……………………………………………………12
Relative Button………………………………………………………………12

Meter Functions

Voltage (V)……………………………………………………………………14
Resistance (Ω ) ………………………………………………………………15
Diode Check( )……………………………………………………………16
Audible Continuity ( )……………………………………………………17
AC or DC Current (A) ………………………………………………………18
Temperature (℃/ 0F) ………………………………………………………19
Frequency (Hz) ……………………………………… …………………… 20
Dwell ( )……… …………………………………………………………21
Duty Cycle (%)………………………………………………………………22
Ms – PULSE& ms- PERIOD (ms) …………………………………………23
RPM ( ) ……………………………………………………………………25

Maintenance………………………………………………………………………26
Replacing The Battery……………………………………………………………26
Battery Installation…………………………………………………………………26
Replacing The Fuses………………………………………………………………27
Trouble Shooting………… ………………………………………………………28

General Specifications…………………………………………………………29
Electrical Specifications…………………………………………………………30
Ready – to – Use Windows® Application Program………………………35

his chapter covers brief, introductory information, You will find:

1 2

 Safety precautions

Safety

DANGER

 Engines produce carbon monoxide which

is odorless, causes slower reaction time,
and can lead to serious injury. When the
engine is operating, keep service areas
WELL VENTILATED or attach the vehicle
exhaust system to the shop exhaust
removal system.

 Set the parking brake and block the

wheels before testing or repairing the
vehicle. It is especially important to block
the wheels on front-wheel drive vehicles;
the parking brake does not hold the drive
wheels.

 Wear an eye shield when testing or

repairing vehicles.

Exceeding the limits of this meter is
dangerous.This will expose you to serious
or possibly fatal injury. Carefully read and
understand the cautions and the
specification limits of this meter.

 Voltage between any terminal and ground

must not exceed 1000V DC or 750V AC.

 Use caution when measuring voltage above 25V DC or 25V AC.
 Circuit tested must be protected by a 20A fuse or circuit breaker.
 Do not use the meter if it has been damaged.
 Do not use the test leads if the insulation is damaged or if metal

is exposed.

CAP

Hz

20A

MAX every

For

MAX

FUSED

15 min.

FUSED

20A MAX

30 sec.

400mA

500V

1000VDC
750VAC

MAX

-PERIOD

AmA

μ

DWELL

RPM
ms

¦¸

RPM

COM

DWELL

ms-PULSE

%duty

V

x10RPM

OFF

24

¡ã

C

CAP

¡ã

¦¸

Hz

20A

A

F

μ

mA

ms
TEMP.

%

CEM

TRIG¡À

3 4

Safety Cont’d

…

Danger

 Avoid electrical shock: do not touch the test

leads, tips or the circuit being tested.

 Do not try a voltage measurement with the

test leads in the 20A or the mA terminal.

 When testing for the presence of voltage or current, make sure

the meter is functioning correctly. Take a reading of a known
voltage or current before accepting a zero reading.

 Choose the proper range and function for the measurement. Do

not try voltage or current measurements that may exceed the
ratings marked on the Function/Range switch or terminal.

 When measuring current, connect the meter in series with the

load.

 Never connect more than one set of test leads to the meter.
 Disconnect the live test lead before disconnecting the common

test lead.

 The mA and the 20A terminals are protected by fuses. To avoid

possible injury or damage, use only in circuits limited to 400mA
or 20A for 30 seconds.

See also…

 Fuse Replacement

Safety Cont’d

…

IMPORTANT

 To maintain accuracy of the meter,replace the discharged battery

immediately when the battery symbol appears on the
meter display.

 Avoid measuring error from outside interference.Keep the meter

away from spark plug or coil wires.

 Avoid damaging the meter when testing voltage.Disconnect the

test leads from the test points before changing functions.

 Do not exceed the limits shown in the table below:

Function

Terminal

Input limit

AC Volts

V-Ω -RPM

750Volts AC rms

DC Volts

1000Volts DC

Frequency

V-Ω -RPM

250VoltsAC/DC

Ohm(resistance)

V-Ω -RPM

250VoltsAC DC

Diode

AC/DC μ A mA

μ A / mA

400mAAC/DC

AC/DC20A

20A

*20AAC/DC

RPM

V-Ω -RPM

250Volts AC/DC

Duty Cycle(%)

Dwell angle

* 20 Amp measurement for 30 seconds maximum.
① Ohms can not be measured if voltage is present, ohms
can be measured only in a non-powered circuit. However,
the meter is protected to 250 volts.

5 6

Notes:

Getting Started

his chapter will help you get started. It describes the basic
functions of the Meter.

7 8

Meter Basics

1. Digital and Analog display

Display features:

a. Four character digital display
b. Symbols to identify function
c. Analog bar graph

The digital display is best for
stable input. The bar graph is best
for rapidly changing input.

2. Function buttons

Press the button to select a
function. A symbol will display to
verify your choice.

3. Rotary Selector Switch

Turn this switch to select a
function or turn the meter OFF.

4. Volts Terminal

The Red test lead is used to
measure Amps, Volts, Ohms,
TEMP, Hz, RPM, Cap, mS and
Dwell.
The Black test lead is used
in the Common(COM) terminal for
all tests

Meter Basics Cont’d…

Digital and Analog display

AC DC Press the Mode button to select Alternating Current

(AC) or Direct Current (DC)

HOLD Press Hold to hold data display or resume testing.

RPM (Tach)

Negative Polarity Indicator
Continuity Test
When Dwell (# of cylinders) is selected with the
rotary switch.
Low Battery Replace the master battery when this
symbol displays.
Analog bar Graph display with polarity.

Units of measure:

Kilo (k=1,000)
Hertz (Hz)
Milli (M=1/1000,)
Volts (V)
mega(m=1,000,000)
ohms (Ω)
dwell degrees
duty percent (%)

9 10

Meter Basics Cont’d…

Function and Range Select

Turn the rotary switch in either
direction to select a function.

Most functions also have ranges.
Always select a range higher
than you expect the current or
voltage to be. Then select a lower
range if better accuracy is
needed.

 If the range is too high, the

readings are less accurate.

 If the range is too low, the

meter shows (over
limit).

Push–button Functions

Mode Button

Press the Mode button to toggle
between DC and AC in the
voltage & current measurements.

Range / # CYL Select

The range is automatically
selected by the meter. You can
also manually select a range or
DWELL (#CYL) range within a
function by pressing the

RANGE button.
Range Exit

To exit the RANGE mode and
return to autoranging, press and
hold the RANGE button for 2
seconds.

Note:

· If the range is too high, the
readings are less accurate.

· If the range is too low, the

meter shows OL (over limit).

+ TRIG

Toggles between a Negative (-)
and Positive (+) Trigger Slope
when the Meter is in the
ms-pulse, %duty cycle mode,
press this button down for 2
seconds to toggle between
a negative(-) and positive (+)
trigger slope.