Model 88 V. Automotive Multimeter. Users Manual

® Model 88 V Automotive Multimeter Users Manual PN 2166623 August 2004, Rev. 1, 1/06 © 2004, 2006 Fluke Corporation. All rights reserved. Printed ...
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Model 88 V

Automotive Multimeter

Users Manual

PN 2166623 August 2004, Rev. 1, 1/06 © 2004, 2006 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies.

LIMITED WARRANTY AND LIMITATION OF LIABILITY Each Fluke 20, 70, 80, 170 and 180 Series DMM will be free from defects in material and workmanship for its lifetime. As used herein, “lifetime” is defined as seven years after Fluke discontinues manufacturing the product, but the warranty period shall be at least ten years from the date of purchase. This warranty does not cover fuses, disposable batteries, damage from neglect, misuse, contamination, alteration, accident or abnormal conditions of operation or handling, including failures caused by use outside of the product’s specifications, or normal wear and tear of mechanical components. This warranty covers the original purchaser only and is not transferable. For ten years from the date of purchase, this warranty also covers the LCD. Thereafter, for the lifetime of the DMM, Fluke will replace the LCD for a fee based on then current component acquisition costs. To establish original ownership and prove date of purchase, please complete and return the registration card accompanying the product, or register your product on http://www.fluke.com. Fluke will, at its option, repair at no charge, replace or refund the purchase price of a defective product purchased through a Fluke authorized sales outlet and at the applicable international price. Fluke reserves the right to charge for importation costs of repair/replacement parts if the product purchased in one country is sent for repair elsewhere. If the product is defective, contact your nearest Fluke authorized service center to obtain return authorization information, then send the product to that service center, with a description of the difficulty, postage and insurance prepaid (FOB Destination). Fluke assumes no risk for damage in transit. Fluke will pay return transportation for product repaired or replaced in-warranty. Before making any non-warranty repair, Fluke will estimate cost and obtain authorization, then invoice you for repair and return transportation. THIS WARRANTY IS YOUR ONLY REMEDY. NO OTHER WARRANTIES, SUCH AS FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSED OR IMPLIED. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY. AUTHORIZED RESELLERS ARE NOT AUTHORIZED TO EXTEND ANY DIFFERENT WARRANTY ON FLUKE’S BEHALF. Since some states do not allow the exclusion or limitation of an implied warranty or of incidental or consequential damages, this limitation of liability may not apply to you. If any provision of this warranty is held invalid or unenforceable by a court or other decision-maker of competent jurisdiction, such holding will not affect the validity or enforceability of any other provision. Fluke Corporation P.O. Box 9090 Everett, WA 98206-9090 U.S.A. 2/02 To register your product online, visit register.fluke.com

Fluke Europe B.V. P.O. Box 1186 5602 BD Eindhoven The Netherlands

Table of Contents

Title Introduction .................................................................................................................... Contacting Fluke ............................................................................................................ Safety Information .......................................................................................................... The Meter's Features ..................................................................................................... Power-Up Options ..................................................................................................... Automatic Power-Off ................................................................................................. Input Alert Feature .................................................................................................. Making Measurements ................................................................................................... Measuring AC and DC Voltage.................................................................................. Measuring Temperature ............................................................................................ Testing for Continuity................................................................................................. Measuring Resistance ............................................................................................... Using Conductance for High Resistance or Leakage Tests ...................................... Measuring Capacitance............................................................................................. Testing Diodes........................................................................................................... Measuring DC or AC Current..................................................................................... Measuring Frequency................................................................................................

i

Page 1 1 1 5 13 13 13 14 14 15 16 18 20 21 22 24 27

Model 88 V Users Manual Measuring Duty Cycle ............................................................................................... Measuring Pulse Width ............................................................................................. Bar Graph ...................................................................................................................... Zoom Mode (Power Up Option Only) ........................................................................ Uses for the Zoom Mode........................................................................................... HiRes Mode ................................................................................................................... MIN MAX Recording Mode ............................................................................................ Smooth Feature (Power Up Option Only) ...................................................................... AutoHOLD Mode ........................................................................................................... Relative Mode................................................................................................................ Using the Meter for Automotive Applications ................................................................. Measuring RPM ........................................................................................................ Testing MAP or BP/MAP Sensors with Frequency Output........................................ Measuring Internal Resistance of an Ignition Coil ..................................................... Measuring Pulse Width on a Port Fuel Injector ......................................................... Testing Ripple Voltage on an Alternator.................................................................... Measuring Voltages on a Typical Oxygen Sensor .................................................... Measuring Starter Circuit Voltage Drop..................................................................... Testing the Throttle Position Sensor Voltage ............................................................ Testing the Throttle Position Sensor Resistance ...................................................... Isolating a Circuit Causing a Current Drain ............................................................... Measuring System Voltage ....................................................................................... Testing for Continuity in a Switch .............................................................................. Maintenance .................................................................................................................. General Maintenance................................................................................................ Testing the Fuse ....................................................................................................... Replacing the Battery................................................................................................ Replacing the Fuses .................................................................................................

ii

29 30 30 30 30 31 31 32 34 34 34 35 38 40 42 44 46 48 50 50 52 54 56 58 58 58 59 60

Contents (continued) Service and Parts ........................................................................................................... Specifications ................................................................................................................. General Specifications............................................................................................... Detailed Specifications ..............................................................................................

iii

60 66 66 67

Model 88 V Users Manual

iv

List of Tables

Table

Title

Page

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Electrical Symbols ................................................................................................................. 88 V Automotive Multimeter Front Controls........................................................................... Input Terminals...................................................................................................................... Rotary Switch Positions......................................................................................................... Pushbuttons .......................................................................................................................... Display Features ................................................................................................................... Functions and Trigger Levels for Frequency Measurements................................................. MIN MAX Functions............................................................................................................... Battery Charge Voltages ....................................................................................................... Replacement Parts ................................................................................................................ Accessories ........................................................................................................................... AC Voltage Function Specifications....................................................................................... DC Voltage, Resistance, and Conductance Function Specifications..................................... Temperature Specifications................................................................................................... Current Function Specifications............................................................................................. Capacitance and Diode Function Specifications ................................................................... Frequency Counter Specifications.........................................................................................

4 5 6 7 8 11 28 33 54 62 65 67 68 68 69 70 71

v

Model 88 V Users Manual 18. 19. 20.

Frequency Counter Sensitivity and Trigger Levels................................................................ 72 Electrical Characteristics of the Terminals ............................................................................ 73 Min Max Recording Specifications ........................................................................................ 74

vi

List of Figures

Figure

Title

Page

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

88 V Automotive Multimeter Front ......................................................................................... Measuring AC and DC Voltage ............................................................................................. Testing for Continuity............................................................................................................. Measuring Resistance ........................................................................................................... Measuring Capacitance......................................................................................................... Testing a Diode ..................................................................................................................... Measuring Current................................................................................................................. Components of Duty Cycle Measurements ........................................................................... Measuring RPM with Inductive Pickup .................................................................................. Testing MAP or BP/MAP Sensors with Frequency Output .................................................... Measuring Internal Resistance on an Ignition Coil ................................................................ Measuring Pulse Width on a Port Fuel Injector ..................................................................... Testing Ripple Voltage on an Alternator ................................................................................ Measuring Voltages on a Typical Oxygen Sensor ................................................................. Measuring Starter Circuit Voltage Drop ................................................................................. Testing the Throttle Position Sensor Resistance................................................................... Isolating Circuit Causing Current Drain .................................................................................

5 14 17 19 21 23 26 29 37 39 41 43 45 47 49 51 53

vii

Model 88 V Users Manual 18. 19. 20. 21. 22.

Measuring the No-Load Voltage of a Battery ........................................................................ Testing for Continuity in a Switch.......................................................................................... Testing the Current Fuses..................................................................................................... Battery and Fuse Replacement............................................................................................. Replaceable Parts.................................................................................................................

viii

55 57 59 61 64

Automotive Multimeter Introduction To register your product, visit register.fluke.com

Introduction XWWarning

Safety Information

Read "Safety Information" before you use the Meter.

The Meter complies with:

The Model 88 V Automotive Multimeter (“the Meter”) is a hand-held, battery-operated measurement device used for voltage, continuity, resistance, current, diode, capacitance, frequency, temperature, RPM, pulse width, and duty cycle measurements.

• • • • •

Contacting Fluke



To contact Fluke, call one of the following telephone numbers: USA: 1-888-44-FLUKE (1-888-443-5853) Canada: 1-800-36-FLUKE (1-800-363-5853) Europe: +31 402-675-200 Japan: +81-3-3434-0181 Singapore: +65-738-5655 Anywhere in the world: +1-425-446-5500

EN61010-1:2001 ANSI/ISA S82.01-2004 CAN/CSA C22.2 No. 1010.1:2004 UL61010-1 Measurement Category III, 1000 V, Pollution Degree 2 Measurement Category IV, 600 V, Pollution Degree 2

In this manual, a Warning identifies conditions and actions that pose hazards to the user. A Caution identifies conditions and actions that may damage the Meter or the equipment under test. Electrical symbols used on the Meter and in this manual are explained in Table 1.

For USA Service: 1-888-99-FLUKE (1-888-993-5853) Or, visit Fluke's Web site at www.fluke.com.

1

Model 88 V Users Manual

XWWarning



To avoid possible electric shock or personal injury, follow these guidelines: •



Do not use the Meter if it is damaged. Before you use the Meter, inspect the case. Look for cracks or missing plastic. Pay particular attention to the insulation surrounding the connectors.



Make sure the battery door is closed and latched before operating the Meter.



Replace the battery as soon as the battery indicator (M) appears.



Remove test leads from the Meter before opening the battery door.



2

Use this Meter only as specified in this manual or the protection provided by the Meter might be impaired.

Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity. Replace damaged test leads before you use the Meter.

• •

• • • •





Do not apply more than the rated voltage, as marked on the Meter, between the terminals or between any terminal and earth ground. Never operate the Meter with the cover removed or the case open. Use caution when working with voltages above 30 V ac, 42 V ac peak, or 60 V dc. These voltages pose a shock hazard. Use only the replacement fuses specified by the manual. Use the proper terminals, function, and range for measurements. Avoid working alone. When measuring current, turn off circuit power before connecting the Meter in the circuit. Remember to place the Meter in series with the circuit. When making electrical connections, connect the common test lead before connecting the live test lead; when disconnecting, disconnect the live test lead before disconnecting the common test lead. Do not use the Meter if it operates abnormally. Protection may be impaired. When in doubt, have the Meter serviced.

Automotive Multimeter Safety Information • •

• •

Do not operate the Meter around explosive gas, vapor, or dust. Use only a single 9 V battery, properly installed in the Meter case, to power the Meter. When servicing the Meter, use only specified replacement parts. When using probes, keep fingers behind the finger guards on the probes.

XWCaution To avoid possible damage to the Meter or to the equipment under test, follow these guidelines: •

Disconnect circuit power and discharge all high-voltage capacitors before testing resistance, continuity, diodes, or capacitance.



Use the proper terminals, function, and range for all measurements.



Before measuring current, check the Meter's fuses. (See "Testing the Fuse").

3

Model 88 V Users Manual Table 1. Electrical Symbols

B

AC (Alternating Current)

F

DC (Direct Current)

I

Fuse

X

Hazardous voltage

P

Conforms to European Union directives.

W

Risk of Danger. Important information. See Manual.

$

Conforms to relevant Canadian Standards Association directives.

M

Battery. Low battery when displayed.

T

Double insulated

R

Continuity test or continuity beeper tone.

E

Capacitance

CAT III

IEC Overvoltage Category III CAT III equipment is designed to protect against transients in equipment in fixedequipment installations, such as distribution panels, feeders and short branch circuits, and lighting systems in large buildings.

t

s

4

Underwriters Laboratories

J

CAT IV

G

Inspected and licensed by TÜV Product Services.

Earth ground

IEC Overvoltage Category IV CAT IV equipment is designed to protect against transients from the primary supply level, such as an electricity meter or an overhead or underground utility service.

Diode

Automotive Multimeter The Meter's Features Table 2. 88 V Automotive Multimeter Front Controls

The Meter's Features Tables 2 through 6 briefly describe the Meter's features.

1

88

2 MIN MAX

RANGE

REL

Number

Description

A

Display

B

Pushbuttons

C

Rotary Switch

D

Input Terminals

AutoHOLD

Hz %

3

4 A

mA A

10A MAX FUSED

COM

400mA FUSED

ayg40f.eps

Figure 1. 88 V Automotive Multimeter Front

5

Model 88 V Users Manual Table 3. Input Terminals Terminal

6

Description

A

Input for 0 A to 10.00 A current measurements (20 A overload for 30 seconds maximum), current frequency, duty cycle, and pulse width measurements.

mA µA

Input for 0 µA to 400 mA current measurements (600 mA for 18 hrs.), current frequency, duty cycle, and pulse width.

COM

Return terminal for all measurements.

I RPM

Input for voltage, continuity, resistance, diode, capacitance, frequency, temperature, duty cycle, pulse width, and RPM measurements.

Automotive Multimeter The Meter's Features Table 4. Rotary Switch Positions Switch Position Any Position

Function When the Meter is turned on, the Meter model number briefly appears on the display.

K

AC voltage measurement

L

DC voltage measurement Press A for RPM o, press again for RPM n. 600 mV dc voltage range

M

Press A for temperature

(T).

Press E for continuity test.

N

e Resistance measurement Press A for capacitance measurement.

O

Diode test

e

DC current measurements from 0 mA to 10.00 A Press A for ac current measurements, from 0 mA to 10.00 A.

f

DC current measurements from 0 µA to 6000 µA Press A for ac current measurements from 0 µA to 6000 µA.

7

Model 88 V Users Manual Table 5. Pushbuttons Button

A (Yellow)

B

8

Switch Position

Function

N

Selects capacitance

M

Selects temperature

g K L

Selects measurement of RPM o or RPM n

e f

Switches between dc and ac current

Power-up

Disables automatic power-off feature (Meter normally powers off in 30 minutes). The Meter reads “PoFF” until A is released.

Any switch position

Starts recording of minimum and maximum values and disables power-off feature. Steps the display through MAX, MIN, AVG (average), and present readings. Cancels MIN MAX (hold for 1 second).

Power-up

Enables the Meter’s calibration mode and prompts for a password. The Meter reads “CAL“ and enters calibration mode. See the 80 Series V Callibration Manual for more information.

Switches between dc and ac current

Automotive Multimeter The Meter's Features Table 5. Pushbuttons (cont.) Button

C

D

Switch Position

Function

Any switch position

Switches between the ranges available for the selected function. To return to autoranging, hold the button down for 1 second.

M

Switches between °C and °F when temperature is selected.

Power-up

Enables the Meter’s smoothing feature. The Meter reads “5___” until C is released.

Any switch position

AutoHOLD captures the present reading on the display. When a new, stable reading is detected, the Meter beeps and displays the new reading.

MIN MAX recording

Stops and starts recording without erasing recorded values.

Frequency counter

Stops and starts the frequency counter.

Power-up

Turns on all LCD segments until D, is released.

Any switch position

Turns the backlight on, makes it brighter, and turns it off.

H Power-up

Hold H down for one second to enter the HiRes digit mode. The “HiRes” icon appears on the display. To return to the 3-1/2 digit mode, hold H down for one second. HiRes=19,999 Changes the default ranging from manual to auto for the V ac and V dc functions. The Meter reads “Avto” until H is released.

9

Model 88 V Users Manual Table 5. Pushbuttons (cont.) Button

E

Switch Position Continuity ReE

Turns the continuity beeper on and off

MIN MAX recording

Switches between Peak (250 µs) and Normal (100 ms) response times.

Hz, Duty Cycle

Toggles the meter to trigger on positive or negative slope.

Power-up

F (Relative mode)

G

Any switch position Power-up Any switch position except diode test Power-up

10

Function

Disables the beeper for all functions. The Meter reads “bEEP” until E is released. Stores the present reading as a reference for subsequent readings. The display is zeroed, and the stored reading is subtracted from all subsequent readings. Enables zoom mode for the bar graph. The Meter reads “2rEL” until F is released. Press G for frequency measurements. Starts the frequency counter. Press again to enter duty cycle mode, and again to measure pulse width (ms). Enables the Meter’s high impedance mode when the mV dc function is used. The Meter reads “Hi2” until G is released.

Automotive Multimeter The Meter's Features Table 6. Display Features

Number

Feature

D

a

E

ayg04f.eps

Number

Feature

Y

A

Indication Polarity indicator for the analog bar graph.

TrigY

Positive or negative slope indicator for Hz/duty cycle triggering, pulse width, RPM.

B

X

The continuity beeper is on.

C

W

Relative (REL) mode is active.

-

Indication Smoothing is active. Indicates negative readings. In relative mode, this sign indicates that the present input is less than the stored reference. Indicates the presence of a high voltage input. Appears if the input voltage is 30 V or greater (ac or dc). Also appears in cal, Hz, and duty cycle modes.

F

Z

G

RS

H

S

Display Hold is active.

I

p

Indicates the Meter is in Peak Min Max mode and the response time is 250 µs.

J

m MAX MIN AVG

K

b

AutoHOLD is active.

Indicators for minimummaximum recording mode. The battery is low. XWWarning: To avoid false readings, which could lead to possible electric shock or personal injury, replace the battery as soon as the battery indicator appears.

11

Model 88 V Users Manual

Number

L

Feature

Indication

A, µA, mA

Amperes (amps), Microamp, Milliamp

V, mV

Volts, Millivolts

µF, nF

Microfarad, Nanofarad

nS

Nanosiemens

%

Percent. Used for duty cycle measurements.

ms

Milliseconds. Used for pulse width measurement.

e, Me, ke

Hertz, Kilohertz

AC DC

Alternating current, direct current

M

°C, °F

Degrees Celsius, Degrees Fahrenheit

N

610000 mV HiRes

P

Indication

Auto

The Meter is in autorange mode and automatically selects the range with the best resolution.

Manual

The Meter is in manual range mode. The number of segments is relative to the full-scale value of the selected range. In normal operation 0 (zero) is on the left. The polarity indicator at the left of the graph indicates the polarity of the input. The graph does not operate with the capacitance, frequency counter functions, temperature, or peak min max. For more information, see “Bar Graph” later in this manual. The bar graph also has a zoom function, as described under "Zoom Mode".

Q

Displays selected range The Meter is in high resolution (Hi Res) mode. HiRes=19,999

R

12

Feature

Ohm, Megohm, Kilohm

Hz, kHz

O

Number

RPMon

oconventional (4 cycle) Counts every other revolution. nwaste spark or 2 cycle. Counts every revolution.

Automotive Multimeter The Meter's Features

Number

-bAtt diSC EEPr Err CAL Err

Feature

0L

Indication Overload condition is detected.

Messages Replace the battery immediately. In the capacitance function, too much electrical charge is present on the capacitor being tested. Invalid EEPROM data. Have Meter serviced. Invalid calibration data. Calibrate Meter.

LEAd

WTest lead alert. Displayed when the test leads are in the A or mA/µA terminal and the selected rotary switch position does not correspond to the terminal being used.

F8-Err

Invalid model. Have Meter serviced.

0PEn

Open thermocouple is detected.

Power-Up Options Holding a button down while turning the Meter on activates a power-up option. Table 5 includes the powerup options.

MAX Recording is enabled, the Meter will not power off. To disable automatic power-off, refer to Table 4.

Input Alert Feature If a test lead is plugged into the mA/µA or A terminal, but the rotary switch is not set to the correct current position, the beeper warns you by making a chirping sound and the display flashes “LEAd”. This warning is intended to stop you from attempting to measure voltage, continuity, resistance, capacitance, or diode values when the leads are plugged into a current terminal. XW Caution Placing the probes across (in parallel with) a powered circuit when a lead is plugged into a current terminal can damage the circuit you are testing and blow the Meter's fuse. This can happen because the resistance through the Meter's current terminals is very low, so the Meter acts like a short circuit.

Automatic Power-Off The Meter automatically turns off if you do not turn the rotary switch or press a button for 30 minutes. If MIN

13

Model 88 V Users Manual

Making Measurements

AC Voltage 88

The following sections describe how to take measurements with the Meter.

Switch Box MIN MAX

Measuring AC and DC Voltage The Meter's voltage ranges are 600.0 mV, 6.000 V, 60.00 V, 600.0 V, and 1000 V. To select the 600.0 mV dc range, turn the rotary switch to mV. To measure ac or dc voltage, refer to Figure 2.

REL

A

mA A

Hz %

COM

400mA FUSED

DC Voltage

88

mV

MIN MAX

RANGE

REL

For better accuracy when measuring the dc offset of an ac voltage, measure the ac voltage first. Note the ac voltage range, then manually select a dc voltage range equal to or higher than the ac range. This procedure improves the accuracy of the dc measurement by ensuring that the input protection circuits are not activated.

AutoHOLD

V

10A MAX FUSED

When measuring voltage, the Meter acts approximately like a 10 MΩ (10,000,000 Ω) impedance in parallel with the circuit. This loading effect can cause measurement errors in high-impedance circuits. In most cases, the error is negligible (0.1% or less) if the circuit impedance is 10 kΩ (10,000 Ω) or less.

RANGE

AutoHOLD

Hz %

V A

mA A

10A MAX FUSED

COM

+

400mA FUSED

aug01f.eps

Figure 2. Measuring AC and DC Voltage

14

Automotive Multimeter Making Measurements

Measuring Temperature

To measure temperature, do the following:

The Meter measures the temperature of a type-K thermocouple (included). Choose between degrees Celsius (°C) or degrees Fahrenheit (°F) by pushing C.

1.

Connect a type-K thermocouple to the Meter’s COM and h terminals.

2.

Turn the rotary switch to M.

XW Caution

3.

Press A to enter temperature mode.

To avoid possible damage to the Meter or other equipment, remember that while the Meter is rated for -200.0 °C to +1090.0 °C and -328.0 °F to 1994.0 °F, the included K-Type Thermocouple is rated to 260 °C. For temperatures out of that range, use a higher rated thermocouple.

4.

Push C to choose Celsius or Fahrenheit.

Display ranges are -200.0 °C to +1090.0 °C and -328.0 °F to 1994.0 °F. Readings outside of these ranges show OL on the Meter display. When there is no thermocouple connected, the display shows OPEn for Meters above serial number (90710501) and OL for meters below serial number (90710501). Note To locate the serial number remove the Meter from the holster. The serial number is on the back of the holster.

15

Model 88 V Users Manual

Testing for Continuity XWCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before testing for continuity. The continuity test features a beeper that sounds as long as a circuit is complete. The beeper allows you to perform quick continuity tests without having to watch the display. To test for continuity, set up the Meter as shown in Figure 3 . Press Eto turn the continuity beeper on or off. The continuity function detects intermittent opens and shorts lasting as little as 1ms. A brief short causes the Meter to emit a short beep.

16

Automotive Multimeter Making Measurements

For in-circuit tests, turn circuit power off. ON (closed)

88

88

OFF (open)

Activates continuity beeper MIN MAX

RANGE

REL

A

mA A

10A MAX FUSED

COM

400mA FUSED

MIN MAX

AutoHOLD

RANGE

REL

Hz %

A

mA A

10A MAX FUSED

AutoHOLD

Hz %

COM

400mA FUSED

ayg03.eps

Figure 3. Testing for Continuity

17

Model 88 V Users Manual

Measuring Resistance XWCaution •



To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before measuring resistance. Follow the manufacturers test procedures when testing air bags. See Table 19 for current levels.

The Meter measures resistance by sending a small current through the circuit. Because this current flows through all possible paths between the probes, the resistance reading represents the total resistance of all paths between the probes. The Meter's resistance ranges are 600.0 Ω, 6.000 kΩ, 60.00 kΩ, 600.0 kΩ, 6.000 MΩ, and 50.00 MΩ. To measure resistance, set up the Meter as shown in Figure 4.

18

The following are some tips for measuring resistance: •

The measured value of a resistor in a circuit is often different from the resistor's rated value.



The test leads can add 0.1 Ω to 0.2 Ω of error to resistance measurements. To test the leads, touch the probe tips together and read the resistance of the leads. If necessary, you can use the relative (REL) mode to automatically subtract this value.



The resistance function can produce enough voltage to forward-bias silicon diode or transistor junctions, causing them to conduct. If this is suspected, press C to apply a lower current in the next higher range. If the value is higher, use the higher value. Refer to Table 19.



For low ohms tests, use 600 Ω and press H for 1 second to enter Hi-Res mode. The display will show 0.01 Ω resolution up to 199.99 Ω.

Automotive Multimeter Making Measurements

In-Circuit Resistance Measurements

Isolating a Potentiometer

Circuit Power

OFF

88

1 3

2 Disconnect

MIN MAX

RANGE

REL

AutoHOLD

Hz %

2

1 3

Isolating a Resistor A

mA A

10A MAX FUSED

COM

400mA FUSED

Disconnect aug06f.eps

Figure 4. Measuring Resistance

19

Model 88 V Users Manual

Using Conductance for High Resistance or Leakage Tests

The following are some tips for measuring conductance: •

High-resistance readings are susceptible to electrical noise. To smooth out most noisy readings, enter the MIN MAX recording mode; then step to the average (AVG) reading.



There is normally a residual conductance reading with the test leads open. To ensure accurate readings, use the relative (REL) mode to subtract the residual value.

Conductance, the inverse of resistance, is the ability of a circuit to pass current. The Meter's 60 nS range measures conductance in nanosiemens (1 nS = 0.000000001 Siemens). Because such small amounts of conductance correspond to extremely high resistance, the nS range lets you determine the resistance of components up to 100,000 MΩ, 1/1 nS = 1,000 MΩ. This test might be used to test DIS coil packs on a car. To measure conductance, set up the Meter as shown for measuring resistance (Figure 4); then press Cuntil the nS indicator appears on the display.

20

Automotive Multimeter Making Measurements

Measuring Capacitance 88

XWCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before measuring capacitance. Use the dc voltage function to confirm that the capacitor is discharged. The Meter's capacitance ranges are 10.00 nF, 100.0 nF, 1.000 µF, 10.00 µF, 100.0 µF, and 9999 µF.

Select Capacitance

MIN MAX

RANGE

A

mA A

10A MAX FUSED

AutoHOLD

Hz %

REL

COM

400mA FUSED

To measure capacitance, set up the Meter as shown in Figure 5. To improve the accuracy of measurements less than 1000 nF, use the relative (REL) mode to subtract the residual capacitance of the Meter and leads. Note If too much electrical charge is present on the capacitor being tested, the display shows “diSC”.

+ + + + + + + +

+ ayg02f.eps

Figure 5. Measuring Capacitance

21

Model 88 V Users Manual

Testing Diodes XWCaution To avoid possible damage to the Meter or to the equipment under test, disconnect circuit power and discharge all high-voltage capacitors before testing diodes. Use the diode test to check diodes, transistors, silicon controlled rectifiers (SCRs), and other semiconductor devices. This function tests a semiconductor junction by sending a current through the junction, then measuring the junction's voltage drop. A good silicon junction drops between 0.5 V and 0.8 V. To test a diode out of a circuit, set up the Meter as shown in Figure 6. For forward-bias readings on any semiconductor component, place the red test lead on the component's positive terminal and place the black lead on the component's negative terminal. In a circuit, a good diode should still produce a forwardbias reading of 0.5 V to 0.8 V; however, the reverse-bias reading can vary depending on the resistance of other pathways between the probe tips.

22

A short beep sounds if the diode is good (