146-4080 Digital Multimeter Specification, Testing, and Maintenance Manual{0374, 0599, 0709} Caterpillar

Caterpillar Products: All

Introduction

Important Safety Information

Illustration 1	g02139237
Think Safety

European Union Compliant, CE Marked

Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.

Improper operation, lubrication, maintenance, or repair of this product can be dangerous and could result in injury or death.

Do not operate or perform any lubrication, maintenance, or repair on this product until you have read and understood the Tool Operating Manual.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the "Safety Alert Symbol" and followed by a "Signal Word" such as "DANGER", "WARNING", or "CAUTION". The Safety Alert "WARNING" label is shown below.

A non-exhaustive list of operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are, therefore, not all inclusive. If a tool, procedure, work method, or operating technique that is not recommended by Caterpillar is used, the operator must be sure that the procedures are safe. The operator must also be sure that the product will not be damaged or made unsafe by any unspecified procedures.

The information, specifications, and illustrations in this publication are based on information that was available at the time that the publication was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete and most current information before you start any job.

When replacement parts are required for this product Caterpillar recommends using Caterpillar replacement parts or parts with equivalent specifications including, but not limited to, physical dimensions, type, strength, and material.

Literature Information

This manual contains safety information, operation instructions and maintenance information and should be stored with the tool group

Some photographs or illustrations in this publication may show details that can be different from your service tool. Guards and covers might have been removed for illustrative purposes.

Continuing improvement and advancement of product design might have caused changes to your service tool, which are not included in this publication.

Whenever a question arises regarding your service tool or this publication, consult Dealer Service Tools (DST) for the latest available information.

Safety Section

The Safety section lists basic safety precautions.

Read and understand the basic precautions listed in the Safety section before operating or performing maintenance and repair on this service tool.

General Information Section

The General Information section describes tooling functions and features. The section provides useful information on individual parts, additional tooling, and resources.

Operation Section

The Operation section is a reference for the new operator and a refresher for the experienced operator.

Photographs and illustrations guide the operator through correct procedures for using the tool group.

Operating techniques outlined in this publication are basic. Skill and techniques develop as the operator gains knowledge of the service tool and the tools capabilities.

Safety Section

Safety Icon Nomenclature

Personal Protection/Important Information

Illustration 2	g02166423
Personal Protection/Important Information

Prohibited Action

No smoking

Hazard Avoidance

Crushing hazard (foot)

Crushing hazard (hand)

Pinch point

Fire hazard

Electrical Shock - Hazard

Fire hazard

General Information Section

Introduction

The 146-4080 Multimeter is an autoranging true RMS digital multimeter with an RS-232 (DB9) serial interface. It is a hand-held, battery powered instrument. It can measure Voltage, current, resistance, duty cycle, temperature, and total harmonic distortion on an AC power line. It can check continuity and diode junctions and can be programmed to compare measurements to desired reference values. The 146-4080 Multimeter is supplied with test leads, protective holster (equipped with a stand rest), 146-8487 Thermocouple Adapter , K-type thermocouple, NEHS0678 Tool Operating Manual. NEHS0682, Maintenance Manual can be ordered separately.

Illustration 3	g02540384
(1) Thermocouple Adapter and K-type thermocouple. (2) Test Leads. (3) Clip Adapter. (4) NEHS0678-01 Operation Manual . (5) 146-4080 RS-232 Digital Multimeter .

Optional Equipment

Illustration 4	g02540387
Optional Equipment for 146-4080 RS-232 Digital Multimeter . (6) 146-8488 Cable Assembly (RS-232 for use with CAT 131-5050 Data View ). (7) NEHS0682-01 Specification, Testing, and Maintenance Manual .

Additional Contact Information

For additional product support questions concerning this tool, contact the Dealer Service Tools Hotline at:

USA: 800-542-8665, Option 1

International: 1-309-578-7372

Note: Continuing improvement and advancement of product design can mean some photographs or illustrations in this publication will show details that are different from your service tool.

Specifications

Table 1

Electrical Specifications
Func.	Range	Res.	Acc.	Max. Input
DC V	400mV 4V 40V 400V 1000V	0.1m V 1mV 10mV 0.1V 1V	0.3% +2 digits 0.75% + 3 digits	1000V
DC A	400µA 4000µA 40mA 400mA 4A 10A	0.1µA 1µA 0.01m A 0.1m A 0.001A 0.01A	0.5% +1 digits 0.5% +1 digits 0.5% +1 digits	µA - 400mA/600V mA - 400mA/600V A - 10A/600V
AC V	4V 40V 400V 750V	1mV 10mV 0.1V 1V	0.75% +3 digits 0.75% +3 digits	750V
AC A	400µA 4000µA 40mA 400mA 4A 10A	0.1µA 1µA 0.01m A 0.1m A 0.001A 0.01A	1.0% +5 digits (45Hz to 1KHz)	µA - 400mA/600V mA - 400mA/600V A - 10A/600V
Ohms	400Ω 4KΩ 40KΩ 400KΩ 4MΩ 40MΩ	0.1Ω 1Ω 10Ω 0.1KΩ 1KΩ 10KΩ	0.5% +10 digits 0.5% +3 digits 1.01% + 10 digits	600V
Hz (1.5Hz to 200KHz)	200Hz 2KHz 20KHz 200KHz 7200KHz	0.01 Hz 0.1 Hz 1 Hz 10 Hz 100Hz	0.05% +2 digits (20,000 Counts)

Table 2

General Specifications
Function	Description
Continuity	Open circuit test Voltage: 1.2V THRESHOLD: Approximately <100Ω
Diode Check	Open circuit test Voltage: 3V MAXIMUM TEST CURRENT: 25mA
Duty Cycle (1.5Hz to 20KHz)	0.0 - 99.9% Accuracy: within ± (0.2% per KHz + 0.1%)
THD Measurement (50/60Hz) (Total Harmonic Distortion)	Voltage ± (2% + 2 digits) Current ± (2% + 2 digits)
DC V	Normal Mode Rejection Ratio: >20dB at 50Hz or 60Hz
	Common Mode Rejection Ratio: >100dB at DC, 50Hz or 60Hz
AC V	Common Mode Rejection Ratio: 85dB at dc to 60Hz
Crest Factor	1:1 through 3:1. For non-sinusoidal waveforms (45Hz to 1KHz), add ± (2% of reading) to the accuracy
FUSE Protection	µ;A or mA: 1A 600V FAST fuse
	A: 15A 600V FAST fuse with >10,000A interrupt rating

Table 3

Temperature Specifications
Range	Resolution	Accuracy	Maximum Input
−40° to -10°C (−40.0° to -14.0°F)	0.1° C (.1° F)	± 4.0°C + 1 digit (± 7.2°F + 1 digit)	60V DC or 24V AC RMS
−10° to 20°C (14.0° to 68.0°F)	0.1° C (.1° F)	± 3.0° C (± 5.4° F)	60V DC or 24V AC RMS
20° to 400°C (68.0° to 752.0°F)	0.1° C (.1° F)	± 1% + 2°C (± 1% + 3.6°F)	60V DC or 24V AC RMS
400° to 1370°C (752.0° to 2498.0°F)	1° C (2.0° F)	± 3.0% of reading	60V DC or 24V AC RMS

Controls and Indicators

Illustration 5	g02540262
146-4080 Digital Multimeter

Controls and Indicators

(1) Digital Display Digital readings are displayed on a 4000 count display with polarity indication and automatic decimal point placement. When the multimeter is turned ON, all display segments and symbols appear briefly during a self-test. The display updates four times per second.

(2) Analog Bar Graph The bar graph provides an analog representation of readings and updates 20 times per second. The 41 segment bar graph illuminates from left to right as the input increases. If the input equals or exceeds 4000 counts on the range selected, the bar graph displays an arrow at the far right for a positive input and an arrow at the far left for a negative input.

(3) Display Back-Light Press HOLD for 2 seconds to turn backlight ON. Back-light turns OFF automatically after 60 seconds to extend battery life. To turn OFF the back-light before the automatic turn OFF, press HOLD for 2 seconds.

(4) Hold Automatically captures a stable reading, beeps, and holds the reading on the display. Freezes a reading in the Recording, Compare, Relative, or Percentage mode.

(5) CMP Enables GO-NO GO test in the Compare mode and works as an Increment button in the Editing mode. Press CMP to compare a reading with the stored HI (high) reference value and the stored LO (low) reference value. The Csymbol appears. A Hi is displayed if the compared reading is higher than the HI (high) reference value and a LO is displayed if the compared reading is lower than the LO (low) reference value. If the compared reading is between the HI (high) reference and the LO (low) reference, PASS is displayed. When in the Editing mode, press arrow to increase the blinking number displayed on the display by 1 digit.

(6) Edit Programming the Reference values. Press EDIT to program a new reference value by using the arrow in the Compare, Relative, or Percentage mode. An external reference source is not needed in these modes. Press EDIT. The 0 at the right side of the display will begin to blink and the arrow at the right of the bar graph will appear. This indicates the value entered is the HI (high) reference value. Use the arrow buttons, to enter the HI (high) reference value that the readings are to be compared to. Press HOLD to select "-" sign. Once the HI (high) reference value is entered (stored), press HI/LO to enter the LO (low) reference value. Press HI/LO and the arrow at the left of the bar graph will appear. This indicates that the value entered is the LOW (low) reference value that the readings are to be compared to.

Note: Both HI and LO reference values must be entered. Select another function with the rotary selector switch to exit this mode.

(7) Range HI/LO Selects the Manual Range mode in the Non-Editing mode. This enables the HI (high) reference value or the LO (low) reference value in the Compare mode. Press RANGE to select the Manual Range mode and turn OFF the AT (autoranging) symbol. (The multimeter remains in the range it was when manual ranging was selected.) Each time RANGE is pressed in the Manual Range mode, the range increases, and a new value is displayed. If the multimeter is already in the highest range, the multimeter wraps around to the lowest range. To exit the Manual Range mode and return to autoranging, press RANGE for 2 seconds. The AT symbol is displayed. When the range is changed manually, the Recording, Percentage, Compare, Relative, and Hold modes are disabled. Press HI/LO (RANGE) to recall the stored reference value in the Compare, Relative, or Percentage mode.

(8) REC Maximum, Minimum, and Average Recording; A left-shift button in the Editing mode. Press REC to enter the Recording mode. The R appears. This allows recording of Maximum, Minimum, and Average values for a series of measurements on the same function and range. The multimeter will beep every time a new maximum or minimum value is recorded. Press REC to scroll through the stored MAX, MIN, and AVG values. When an overload is captured, a beeper tone sounds and OFL (overload) is displayed. This multimeter can record for 24 hours in this mode. In the Recording mode, Auto Power Off is disabled and the multimeter automatically switches to Standby mode after approximately 1 hour to save battery life unless the Standby mode is disabled. To disable the Standby mode, turn the rotary switch from "OFF" to any function ("ON") position while pressing HOLD. If an ineffective button is pressed, the multimeter will sound 2 consecutive beeps indicating the button function does not work in the Recording mode. To exit and erase recorded readings, press REC for 2 seconds. In the Editing mode, press the arrow button to shift the blinking number position to the left by one decimal point. When the blinking number is at the left, the number will stay at the same position even if the arrow button is pressed.

(9) REL Relative Readings in the Relative mode; A right-shift button in the Editing mode. In the Relative mode, the difference between the stored reference value and the measured reading value is displayed. Press REL to enter the Relative mode. The REL symbol is displayed and the bar graph pointer is at the center of the scale. Press EDIT to program the reference value. Use the arrow buttons, to enter the value the readings are displayed in relation to. After the value is entered, press EDIT to exit the Editing mode. To recall the stored value, press HI/LO. All measurements are displayed as the difference between the stored value and the measured value. Negative readings are lower than the stored value. Positive readings are higher than the stored value. Push REL to exit this mode. In the Editing mode, press the arrow button to shift the blinking number position to the left by one decimal point. When the blinking number is at the far right, the number will stay at the same position even if the arrow button is pressed. RS-232 Communication Mode: Press and hold REL for two seconds to activate the RS-232 Communication mode. The RS-232 symbol will appear on the upper left of the display.

(10) % Readings in the Percentage mode, a decrement button in the Editing mode. In the Percentage mode, the difference in percentage between the stored reference value and the measured value is displayed. Press % and the percent symbol will come on the display, and the bar graph pointer will be at zero on the scale. To recall the stored reference value, press HI/LO. Press EDIT. Using the arrow buttons, enter the value that the readings are displayed as a percentage of. Once the value is entered, press EDIT to exit this mode. All measurements will be displayed as the difference in percentage between the stored reference value and the measured value. Negative readings are lower than the stored value. Positive readings are higher than the stored value. Press % to exit this mode. In the Editing mode, press the arrow button to decrease the blinking number on the display by 1 digit.

(11) DC/AC Toggles between DC and AC, toggles between °C and °F in the Temperature mode. Press the DC/AC button to toggle between DC and AC when measuring Volts (except mV) or Amperes. When AC is selected, the "AC" symbol is displayed. Press °C/°F to toggle between °C and °F when measuring temperature. When the Centigrade scale is selected, the "C" symbol is displayed and when the Fahrenheit scale is selected, the "F" symbol is displayed.

(12) THD @ 50/60Hz Total Harmonic Distortion measurement of the Line Voltage or Current at 50/60Hz. When measuring AC Voltage or amperes in the 50Hz or 60Hz power line, press DC/AC for 2 seconds to select the THD @ 50/60Hz mode. This mode measures THD (Total Harmonic Distortion) in percentage (%) from the 50Hz or 60Hz power line. In the THD @ 50/60Hz mode, the digital reading, the TRUE-RMS value of Voltage and amperes being measured, disappears and the symbol "%" and decimal points are displayed. After 2 seconds, the THD value in percentage (%) will be displayed. To exit this mode, press DC/AC for 2 seconds. The "%" symbol disappears.

(13) OFF Power to the multimeter is turned OFF.

(14) Rotary Switch Select functions by setting the rotary switch.

(15) Safety Shutter Prevents inadvertent connections to the current terminals.

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NOTICE
Always remove inputs before turning the rotary switch.

(16) A (Amperes Input Terminal) Connect the red test lead to measure current on the 4A or 10A AC or DC Ampere functions.

(17) mAµA (Milliamp/Microamp Input Terminal) Connect the red test lead into this terminal to measure µA or mA on either AC or DC ampere functions.

(18) VΩHz (Volts, Ohms, Diode Test, Frequency, Temp, and Temperature Input Terminal) Connect the red test lead into this terminal for all AC V, DC V, Ohms, continuity test, diode test, frequency, and duty cycle functions. To measure temperature, connect a thermocouple adapter into both this terminal and the COM input terminal.

(19) COM (Common Terminal) Connect the black test lead into this terminal for all measurements. To measure temperature, connect a thermocouple adapter into this terminal.

Units

Table 4

Exponents	Description
%	Percentage Annunciation in the Percentage (%) mode, the THD @ 50/60Hz mode, and Duty Cycle mode.
mV	Millivolts (1 x 10-3 V)
A	Amperes (Amps)
mA	Milliamperes (1 x 10-3 Amps)
µA	Microamperes (1 x 10-6 Amps)
Ω	Ohms
KΩ	Kilohm ( 1 x 103 Ohms)
MΩ	Megohm (1 x 106 Ohms)
Hz	Hertz (1 cycle/sec)
KHz	Kilohertz (1 x 103 cycles/sec) Standby Mode

Standby Mode

If the multimeter is ON and inactive for approximately 30 minutes (1 hour in the Recording mode), the multimeter will automatically switch to Standby mode. "BAT", will blink and the circuit power is reduced to save battery life. To resume operation, press any button or control function. To disable the Standby mode, turn the rotary switch from OFF to any function while pressing "HOLD".

RS-232 Connection to Data View

The Cat 146-4080 Multimeter has an RS-232 output which can be used to connect it to a PC or to the 131-5050 Cat Dataview Hardware using the 146-8488 Cable Assembly (RS-232 male/male). Dataview is a portable diagnostic tool that allows measurements from the Cat Multimeter, or sensors installed on a machine to be viewed on a PC or recorded in a built-in data logger. The readings taken by the multimeter can then be displayed along with other readings taken by the sensors and can be shared with other PC programs such as SIS or ET.

Note: Cat Dataview has a software program that runs on the PC. The earliest version of this program is Version 1.0. The 1.0 version will not work with the Cat multimeter. A later version will support the Multimeter and will be provided free to anyone who owns a Dataview. It will be available in early 1998. Contact CSTG for more information.

As shown in Illustration 6, Dataview has an RS-232 connector (1) located at the left end of the front panel. To use the multimeter with Dataview, use the 9-pin 146-8488 RS-232 Cable (RS-232 male/male) to connect the RS-232 connector located on the rear of the multimeter to the RS-232 connector on the front panel of Dataview. If the serial number of your Dataview is 100 or less, use the connector adapter provided with the cable. Later Dataview units have a male pin connector for the RS-232 input and do not require the cable adapter. With the multimeter and Dataview ON, run the Dataview software program on the PC to observe or log the readings. Complete instructions are given in the Dataview software manual. To prevent the multimeter from automatically switching to the standby mode disable the Standby mode as described in the previous section.

Note: Some 131-5050 Data View Hardware units were manufactured with incorrect internal wiring of the RS232 connector on the front panel. This problem will cause the Cat 146-4080 Multimeter to only work with Dataview when the Dataview hardware is connected to external power. The Multimeter will not work with Dataview when it is on internal battery powered operation. Most of these units have been corrected at the factory, however some may have been already sold when the problem was discovered. Listed below are the serial numbers of the units which had the problem. Reworked units have the letter "A" after the serial number. If your unit has one of the serial numbers listed below and does not have the letter "A" following the serial number, contact CSTG to get it repaired free of charge. Here are the Serial numbers located on the rear panel of the bad units: (S/N: CDV0056-60), (S/N: CDV0120-127), (S/N: CDV0129-131), (S/N: CDV0136-178), and (S/N: CDV0180-182).

Illustration 6	g02540277

Using Test Leads

Use only test leads which are rated for 1200 V. Although these test leads are rated for 1200 V, do not try to measure any Voltage greater than 1000 V DC or 750 V AC.

Basic Electrical Tests And Measurements

Measuring Voltage

Autoranging

Each time a different function is selected with the rotary switch the multimeter automatically defaults to the Autoranging mode and AT appears on the display. In the Autoranging mode, the meter automatically selects the proper range for the reading.

To exit the Autoranging mode and select the Manual range mode, press RANGE. AT will disappear.

To exit the Manual range mode and return to the Autoranging mode, press RANGE for 2 seconds. ATappears on the display.

DC Volts

Illustration 7	g02540297

To measure DC Volts:

1. Set function and range switch to the desired DC Volts range when in the Manual Ranging mode.

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NOTICE
To measure an unknown Voltage and prevent multimeter damage, always start with the highest range and reduce the setting as required to obtain a satisfactory reading.

2. Connect the red test lead into the VΩHz input terminal and the black lead into the "COM" input terminal of the instrument.

3. Touch the test probes to the circuit to be tested.

4. The measured Voltage will appear on the display.

5. If the red test lead is connected to the negative (or lower Voltage) side of the circuit, a minus sign will appear at the left of the display.

6. Remove the test probes from the circuit.

AC Volts

To measure AC Volts:

1. Set function and range switch to the desired AC Volt range when in the Manual Ranging mode.

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NOTICE
To measure an unknown Voltage and prevent multimeter damage. To prevent personal injury, always start with the highest range and reduce the setting as required to obtain a satisfactory reading.

2. Connect the red test lead into the VΩHz input terminal and the black lead into the "COM" input terminal of the instrument.

3. Touch the test probes to the circuit to be tested.

4. The measured Voltage will appear on the display.

5. Remove the test probes from the circuit.

Three-Phase AC Volts

Three-phase circuits line-to-line Voltage is higher than the rated line-to-ground three-phase Voltage. It is important not to exceed the maximum AC (RMS) rating of 750 V AC. To find the RMS Voltage line-to-line on a three-phase power line, multiply the rated line-to-ground Voltage by the square root of 3 (approximately 1.732).

For example in a 480 V three-phase line circuit (that is, 480 V line-to-ground), the total available Voltage line-to-line is about 832 V AC (= 480 V x 1.732).

Note: In some DC and AC Voltage ranges with the test leads not connected to any circuit, the display may show fluctuating readings due to the high input impedance. This is normal. When the test leads are connected to a circuit, a real measurement is displayed.

Testing Magnetic Pickups

When measuring output Voltage from magnetic pickups, which are sensing gear teeth, always use ACV in the manual range mode, rather than Autoranging mode. Due to the high frequency output of the pickup, the Digital Multimeter may not accurately display the correct Voltage when Autoranging is used. Putting the Digital Multimeter into manual range mode and selecting the desired range, allows the meter to obtain the most accurate reading. To do this, press the RANGE button once to activate manual range mode, and press the RANGE button again to change to the desired scale.

Resistance (Ohms)

When measuring resistance, be sure that the contact between the test leads and the circuit under test is good. Dirt, oil, solder flux, or other foreign matter seriously affect the reading value.

Illustration 8	g02540303

To measure ohms:

1. Set function switch to the desired Ω position.

2. Connect the black test lead into the "COM" input terminal and the red test lead into the voltage Ω Hz input terminal.

3. Connect the test probes to the circuit to be measured.

4. The measured resistance is displayed.

Note: To measure critically low ohm values, touch tips of test leads together and record the reading. Subtract this reading from any additional measurement to obtain the most accurate value.

Continuity Test and Diode Test

During a continuity test, a measured value of approximately 100W or less causes the multimeter to emit a continuous tone.

Diode Test

The diode test will check diodes, transistors, and other semiconductors for opens, shorts, and normal operation.

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NOTICE
Never connect the test leads to a source of Voltage when the rotary switch is set to the diode position.

Illustration 9	g02540312

To check a diode:

1. Set the function switch to the correct position.

2. Connect the black test lead into the COM input terminal and the red test lead into the VWHz input terminal.

3. Touch the red test probe to the Anode (+ side, non-banded end) and the black test probe to the Cathode (- side, banded end).

4. If the diode is good, the reading should indicate 0.3 to 0.8 V on the display.

5. Reverse the red and black probes on the diode, if the display reads OFL (the overload sign), the diode is good.

Note: A defective diode will read OFL (the overload sign) or 0.00 no matter how the test probes are connected.

Current (AMPS)

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NOTICE
The current functions are protected by a fuse rated at 600 V. To avoid damage to the instrument, current sources having open circuit Voltages greater than 600 V DC or AC must not be measured.

To measure current, turn power OFF. Open the circuit and connect the test leads in series with the current. Turn power on, to measure current.

Illustration 10	g02540317

To measure DC (or AC) Amps:

1. Set function and range switch to the desired DC Amps or AC Amps range. To measure an unknown value, always start with the highest range and reduce the setting as required to obtain a satisfactory reading.

2. Connect the red test lead into the mAµA input terminal (connect the red test lead into the "A" input terminal for the 4A or 10A ranges) and the black test lead into the "COM" input terminal.

3. Turn power OFF from the circuit to be tested.

4. Connect the test probes in series to the circuit to be tested.

5. Turn power ON to the circuit, the measured current is displayed.

6. Turn power OFF to the circuit before disconnecting the test probes from the circuit.

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NOTICE
Never connect the test leads across a Voltage source while the rotary switch is set to Amps. This can cause damage to the circuit under test or the Multimeter.

THD @ 50/60Hz Mode

The multimeter indicates the RMS value of the 3rd harmonic as a percentage of the RMS value of the fundamental frequency in the 50Hz or 60Hz and 110/220 V AC range used in power lines. In this application, the 3rd harmonic content is a useful indication of the THD value.

In general, there are two ways to express the THD value:

THD-F = Total Harmonic Distortion as a percent of the fundamental frequency.

THD-R = Total Harmonic Distortion as a percent of the total rms value.

When measuring line Voltage, a maximum THD level of 5% or less is considered acceptable. Below the 5% level, both measurements (THD-R and THD-F) are essentially the same. For the THD levels above 5%, convert THD-R readings to THD-F readings using either the following formula or the conversion chart.

F(%) = 100 x R(%)

Square Root of [1000-R2(%)] (formula)

Where F (%) = THD-F (%) and R (%) = THD-R (%)

Table 5

THD-R (%) versus THD-F (%) Chart
THD-R (%)	THD-F (%)
0	0
5	5.01
10	10.05
15	15.17
20	20.41
25	25.82
30	31.45
35	37.36
40	43.64
45	50.39
50	57.74
55	65.86
60	75
65	85.53
70	98.02
75	113.39
80	133.33
85	161.36
90	206.47
95	304.24
100	Infinity

Crest Factor versus THD-R (%) or THD-F (%)

A Crest Factor indicates whether harmonic contents are included or not in the power line.

To measure THD-R (%) in the power line:

1. Set function and range switch to the AC Volts or Amps range.

2. To measure Voltage or amperes in the 50Hz or 60Hz power line, press and hold the DC/AC button for 2 seconds to select the THD @ 50/60Hz mode.

3. In the THD mode, the digital reading (True-RMS value of Voltage or amperes being measured) disappears and the symbol "%" and decimal points are displayed.

4. After 2 seconds, the THD-R (%) will be displayed.

5. To exit this mode, press and hold the DC/AC button for 2 seconds. The % symbol disappears and the multimeter will return to the AC functions.

Duty Cycle

Duty Cycle is the percentage (%) of the time that an input signal is above the trigger level (or below the trigger level if the negative trigger slope is selected). Press RANGE to select the trigger slope. An arrow in the lower left corner for a negative slope indicates a negative trigger slope. An arrow in the lower right corner of the display indicates a positive slope. The multimeter defaults to a negative trigger slope.

Temperature

Temperature is measured in either degrees Celsius or Fahrenheit using K-type thermocouple. The temperature measurement range of the K-type thermocouple is −40° to +1370°C (-40.0° to +2498.0°F).

There are available in the Caterpillar parts system, some optional type-K thermocouples: 8T-0933 type-K Thermocouples , 8T-0934 type-K Thermocouples , 8T-0935 type-K Thermocouples , 8T-0936 type-K Thermocouples , and 8T-0458 type-K Thermocouples . These thermocouples are used with the following Probe Seal Adapters; except for the 8T-0458 bead type Thermocouple .

Table 6

Thermocouple Adapters
Part No.	Description
5P-2720	Adapter, 1/8 in NPT
5P-2725	Adapter, 1/4 in NPT
4C-4547	Adapter, 1/2 in O-Ring
5P-3591	Adapter, 9/16 in O-Ring
4C-4545	Adapter, 3/4 in O-Ring

Illustration 11	g02540336
Thermocouple Probe. Probe lengths are: 8T-0933 Thermocouple Probe , 25.4 mm (1.00 inch) long 8T-0934 Thermocouple Probe , 38.1 mm (1.50 inch) long 8T-0935 Thermocouple Probe , 63.5 mm (2.50 inch) long 8T-0936 Thermocouple Probe , 89.9 mm (3.50 inch) long

To measure temperature:

1. Set the rotary switch to the TEMP position.

2. Connect the thermocouple adapter into the COM input terminal and the TEMP input terminal observing the proper polarity.

3. Connect a K-type thermocouple probe into the thermocouple adapter observing the proper polarity.

4. Read the temperature on the display.

Note: The multimeter automatically defaults to the Centigrade scale. To measure in Fahrenheit, toggle the DC/AC button when the rotary switch is set to the TEMP position.

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NOTICE
Repeated sharp flexing can break the thermocouple lead. To prolong lead life, avoid sharp bends in the lead, especially near the connector.

Battery

To replace the battery:

1. Turn the rotary switch to the OFF position.

2. Remove two screws and remove battery cover.

3. Remove battery from multimeter and disconnect it. Replace the battery with a 1U-9534 Battery (9 V alkaline) or 1U-9539 Battery (9 V heavy-duty).

4. Install rear cover and replace two screws.

Fuse Test

To test internal fuses:

1. Set the rotary switch to the diode position.

2. To test F2 (15A, 600V), connect the test lead into the VΩHz input terminal and touch the probe to the A input terminal. The display should read about 0.000 V. If the display reads OFL (overload), replace the fuse and test again. If any other value is displayed, have the multimeter serviced.

3. To test F11 (1A, 600V), touch the probe to the mAµA input terminal. The display should read approximately 1.2 V. If OFL (over-load) is displayed, replace the fuse and test again. If any other value is displayed, have the multimeter serviced.

Fuse Replacement

Illustration 12	g02540345

To replace fuse:

1. Turn the rotary switch COUNTERCLOCKWISE to the OFF position.

2. Remove two screws and remove battery cover.

3. Remove and disconnect battery.

4. Remove the back cover after removing the three screws located on the back of the multimeter.

5. Separate the front and rear housing.

6. Remove the four screws (1), (Illustration 12) located on the top of the printed circuit board.

7. Carefully separate the fuse printed circuit board from the Display Printed Circuit Board (LCD PCB) by pulling straight up on it.

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Illustration 13	g02540348

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NOTICE
Do not move the position of the switch contact disk on printed circuit board. Make sure the position of the switch contact disk is the same as position as shown (Illustration 13, Position A). If the contact disk is not in the proper position the selector switch will not select the proper function after the multimeter is reassembled.

8. Replace the fuse with the following ratings: F2: 9U-6398 Fuse (15 Amp, 600 V RMS) (Buss- Fast-Acting KTK-15). F11: 3N-5612 Fuse (1 Amp, 600 V RMS) (BUSS- BBS-1).

9. Connect the Fuse Printed Circuit Board to the Display Printed Circuit Board with the four screws.

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NOTICE
Make sure that the selector switch is turned COUNTERCLOCKWISE in the OFF position. If the selector switch is not COUNTERCLOCKWISE in the OFF position, the selector switch will not select the proper function after the multimeter is reassembled.

10. Snap the front and rear housing together and install the screws.

11. Connect and install the battery.

12. Install battery cover and two screws.

For any technical information or technical assistance, contact EXTECH Instruments at (617) 890-7440 or by fax at (617) 890-7864.

Warranty and Service

EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment. If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (617) 890-7440 or by fax (617) 890-7864 for authorization. A Return Authorization (RA) number must be issued before any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance, and proper packaging to prevent damage in transit.

This warranty does not apply to defects from action of the used such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. Extech specifically disclaims any implied warrants or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental, or consequential damages. Extech's total liability is limited to repair or replacement of the product.

The warranty set forth above is inclusive and no other warranty, whether written or oral, is expressed or implied.