M3500A

Picotest Corp M3500A User Manual

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PICOTEST®

M3500A

6.5 Digit Digital Multimeter

Printed date: 02/2009

User’s Manual

M3500A DMM

User’s Manual

Table of Contents

1 GENERAL INFORMATION............................................................................................... 6

1.1 FEATURE OVERVIEW..................................................................................................... 6

1.2 WARRANTY INFORMATION ...........................................................................................7

1.3 PRECAUTION OF OPERATION .......................................................................................8

1.4 UPKEEP OF M3500A ...................................................................................................9

1.5 SAFETY INFORMATION.................................................................................................. 9

1.6 SYMBOLS AND TERMS ................................................................................................10

1.7 INSPECTION ................................................................................................................11

1.8 OPTIONS AND ACCESSORIES..................................................................................... 12

1.9 M3500A’S DIMENSION.............................................................................................13

2 OVERVIEW ...........................................................................................................................14

2.1 SETTING UP YOUR M3500A DIGITAL MULTIMETER .................................................. 14

2.1.1 To adjust the handle............................................................................. 14

2.1.2 To connect the power........................................................................... 17

2.1.2.1 To convert the voltage ..........................................................................17

2.1.2.2 To change the fuse.................................................................................20

2.1.3 Factory Default When Power-ON .....................................................24

2.2 FEATURES .......................................................................................................................26

2.3 M3500A FUNCTION INTRODUCTION .......................................................................26

2.3.1 The Front Panel .............................................................................................26

2.3.2 The Display ....................................................................................................30

2.3.2.1 Annunciators at Upper Side.................................................................31

2.3.2.2 Annunciators at Right Side ..................................................................31

2.3.3 The Rear Panel ..............................................................................................32

3 BASIC MEASUREMENT FUNCTION..........................................................................34

3.1 VOLTAGE MEASUREMENTS (DC & AC).................................................................... 34

3.2 CURRENT MEASUREMENTS (DC & AC) ................................................................... 36

3.3 RESISTANCE MEASUREMENTS (2 & 4-WIRE)..........................................................38

3.4 FREQUENCY & PERIOD MEASUREMENTS................................................................... 40

3.5 CONTINUITY MEASUREMENTS....................................................................................41

3.6 DIODE MEASUREMENTS ............................................................................................. 42

3.7 TEMPERATURE MEASUREMENTS ................................................................................43

3.7.1 Thermocouple Measurements ...........................................................44

3.7.2 RTD Measurements ............................................................................... 44

3.7.2.1 2-Wire RTD Measurements..................................................................45

3.7.2.2 3-Wire RTD Measurements..................................................................46

3.7.2.3 4-Wire RTD Measurements..................................................................48

4 FRONT PANEL OPERATIONS......................................................................................51

4.1 MEASUREMENT CONFIGURATION ..............................................................................51

4.1.1 Set ADC (Auto Zero & Auto Gain)................................................... 51

4.1.2 Filter ............................................................................................................54

4.1.2.1 AC Filter ......................................................................................................54

4.1.2.2 Digital Filter..................................................................................................55

4.1.3 Resolution Setting (Digits) ................................................................. 57

4.1.4 DC Input Resistance..............................................................................59

4.1.5 Threshold Resistance (Continuity)...................................................61

4.1.6 Range (Manual & Auto)........................................................................61

4.1.7 Rate (Integration Time).......................................................................63

4.1.8 S e n s o r S e l e c t i o n f o r Temperature Measurements......................................... 64

4.1.9 Remote Interface Selection................................................................68

4.1.10 Input Terminal Switch .......................................................................69

4.2 TRIGGER OPERATIONS ............................................................................................... 70

4.2.1 Trigger Mode............................................................................................70

4.2.2 Trigger Source......................................................................................... 72

4.2.3 Trigger Setting ........................................................................................74

4.3 MATH OPERATIONS ....................................................................................................78

4.3.1 Ratio............................................................................................................79

4.3.2 % (Percent)..............................................................................................80

4.3.3 Min/Max .....................................................................................................81

4.3.4 Null .............................................................................................................. 83

4.3.5 Limits Test ................................................................................................ 84

4.3.6 MX+B ..........................................................................................................86

4.3.7 dB/dBm ......................................................................................................88

4.4 OTHER SYSTEM RELATED OPERATIONS.................................................................... 92

4.4.1 Display........................................................................................................92

4.4.2 Beeper ........................................................................................................94

4.4.3 Reading Memory (Store & Recall) ...................................................95

4.4.4 Sensitivity Band (Hold)........................................................................97

4.4.5 Scanning (Scan) .....................................................................................98

4.4.6 Stepping (Step) .................................................................................... 102

4.4.7 Initial Mode............................................................................................. 104

4.4.8 Language................................................................................................. 105

4.4.9 Error Condition......................................................................................105

4.4.10 Firmware Revision .............................................................................106

4.4.11 Calibration ............................................................................................107

4.4.12 Self-Test .............................................................................................. 108

5 REMOTE INTERFACE OPERATIONS..........................................................................113

5.1 PASS/FAIL OUTPUT FROM USB CONNECTOR........................................................ 113

5.2 SETTING UP FOR REMOTE INTERFACE....................................................................114

5.3 REMOTE INTERFACE COMMANDS............................................................................. 115

6 ERROR MESSAGES ......................................................................................................... 127

6.1 ERROR TYPE ..............................................................................................................128

6.1.1 Execution Errors ...................................................................................128

APPENDIX............................................................................................................................... 132

A. SPECIFICATION LIST..................................................................................................... 133

B. GENERAL SPECIFICATIONS........................................................................................... 136

C. REMOTE INTERFACE REFERENCE .................................................................................137

C.1 An Introduction to the SCPI Language ..............................................137

C.2 Output Data Formats................................................................................ 142

C.3 The MEASure? Command........................................................................ 142

C.4 The CONFigure Command.......................................................................144

C.5 The Measurement Configuration Command..................................... 146

C.6 The Math Operation Command.............................................................153

C.7 The Triggering Commands...................................................................... 156

C.8 The System-Related Commands..........................................................157

C.9 The SCPI Status Pattern..........................................................................159

C.10 Status Reporting Commands...............................................................167

C.11 SCPI Compliance Information.............................................................169

C.12 IEEE-488 Compliance Information.................................................... 171

D. ABOUT APPLICATION PROGRAMS ................................................................................ 173

1 General Information

This section contains general information about PICOTEST M3500A

Multimeter. The information is shown below:

z Feature Overview z Warranty Information z Safety Information z Symbols and Terms z Specifications z Inspection z Options and Accessories

If you have any questions after reading this information, please contact

your local service representative.

1.1 Feature Overview

M3500A is a 6.5 digit digital multimeter. It has 0.0015% 24-hour basic

DC voltage accuracy at 10V range and 0.002% 24-hour basic resistance

accuracy at 10kΩ range. At 6.5 digit, the multimeter delivers 50

triggered RDGS/sec via remote interface. At the fast 4.5 digit, it reads

over 2000 RDGS/sec into its internal buffer. M3500A provides wide

measurement ranges:

※ Note: The 24-hour measurement is subject to calibration accuracy.

z DC voltage: 0.1V, 1V, 10V, 100V & 1000V. z AC voltage: 0.1V, 1V, 10V, 100V & 750V. z DC current: 10mA, 100mA, 1A & 3A. z AC current: 1A & 3A. z 2 & 4-wire resistance: 100Ω, 1KΩ, 10KΩ, 100KΩ, 1MΩ, 10MΩ &

100MΩ.

z Frequency: From 3Hz to 300kHz. z Period measurement. z Diode measurement. z Continuity measurement for resistance. z Thermocouple temperature & RTD measurements.

Some additional capabilities of M3500A include:

z Full math functions – dB, dBm, MX+B, ratio, %, Max/Min, null &

limits.

z Optional multipoint scanner card – For internal scanning, options

include M3500–opt01, a 10-channel, general-purpose card.

z USB and GPIB (Optional) remote control interface. z Through Microsoft Office Word & Excel for remotely storing and

recalling the measured values.

z Through M3500 AP software for simulating the real operation on PC.

1.2 Warranty Information

If the equipment is used in a manner not specified by the manufacturer,

the protection provided by the equipment may be impaired.

1. Warranty: PICOTEST CORP. guarantees that this product meets its

published specifications at the time of shipment from the factory.

Under proper installation it should work as expected.

2. Warranty Period: This equipment is warranted against defects in

material and manufacturing for a period of one year from the date of

shipment. During the warranty period, PICOTEST is responsible for

necessary repairs as long as the product can be proved to be

defective.

For warranty service or repair this product must be returned to a

service facility designated by PICOTEST. Please contact your local

service representative.

3. Excluded Items: This warranty does not include consumptive parts

such as fuses, buttons and relays. Neither does this warranty cover

defects caused by improper installation, improper or insufficient

maintenance, unauthorized modification, improper operation,

ignorance of environmental specifications or improper software or

interfacing.

4. Remarks: z No other warranty is expressed or implied, except for the above

mentioned.

z The remedies provided herein are the buyer’s sole and exclusive

remedies. PICOTEST shall not be liable for any direct, indirect, special,

incidental or consequential damages.

Limitation of warranty

1. Our warranties do not cover any damage resulting from unauthorized

modification or misuse.

2. Unless mentioned elsewhere in this document, our warranty does not

apply to fuses, probes, and problems arising from normal wear or

user’s failure to follow instructions.

3. Our warranties do not apply on any direct, incidental, special, or

consequential damages.

4. The above warranties are exclusive and no other warranty is

expressed or implied. PICOTEST disclaims any implied warranties of

MERCHANTABILITY, SATISFACTORY QUALITY, and FITNESS for any

particular reasons.

1.3 Precaution of Operation

z Please carefully read the manual before operating this device. z This manual is for reference only. Please consult your local service

representative for further assistance.

z The contents of this manual may be amended by the manufacturer

without notice.

z Never dismantle the equipment by any unauthorized personnel, or

equipment may be damaged.

z The equipment has been strictly tested for quality before delivery

from our factory. However, this equipment must not be used in

dangerous situations where damage may result.

z This product should be placed in a safe area in case of unpredictable

personnel use.

z The rear protective conduct terminal needs to be connected to the

actual earth ground or electric shock may occur.

z The patent and related documents for the equipment belong to

PICOTEST CORP. and they aren’t allowed to be used by others

without permission.

1.4 Upkeep of M3500A

z Although M3500A multimeter is very durable and weather resistant,

care should be taken not to expose it to severe impact or pressure.

z Keep M3500A far from water and damp environment. z Calibration will be taken every year. Please contact with your local

service representative for more information.

z If the incorrect display or abnormal beeps occurred you should stop

using the equipment at once.

z Do not use the Meter around explosive gas or inflammable vapor. z Wipe the surface of M3500A multimeter with a piece of dry and clean

cloth.

1.5 Safety Information

Caution! Please read through the following safety information

before using the product.

To avoid possible electric shock or personal injury, please read and follow

these guidelines carefully:

z Follow the guidelines in this manual and DO NOT use the Meter if the

case is damaged. Check the Meter case and terminals, and make sure

all the devices are in the proper positions.

z Do not apply excessive voltage to the Multimeter. Apply voltage

within the rated range only.

z Use caution when measuring voltages above 30 V RMS, 42 V peak, or

60 V DC. These voltages pose an electric shock hazard.

z When using the probes, always keep your fingers behind the finger

guards.

z Always connect the common test leads (black) before connecting the

live test leads (red), and disconnect the live test leads (red) before

disconnecting the common test leads (black). This will reduce the

chance of an electric shock.

z Disconnect circuit power and discharge all high-voltage capacitors

before testing resistance, continuity, diodes or capacitance.

z If you need to open the Meter case or replace any parts, read the

instruction in this manual first. You must be a qualified personnel to

perform this action.

z When replacing fuses, use only the same type and same rating as

specified.

z Do not try to operate the Meter if it is damaged. Disconnect the power

from the equipment and consult the local service representative.

Return the product to PICOTEST service department if necessary.

1.6 Symbols and Terms

This symbol indicates hazards that may cause damages to the

instrument or even result in personal injury.

This symbol indicates high voltage may be present. Use extra

caution before taking any action.

This symbol indicates the frame or chassis terminal presented need

to be connected to the actual earth ground.

This symbol indicates “Protective Conductor Terminal”.

This symbol indicates earth (ground) terminal.

This symbol indicates this product complies with the essential

requirements or the applicable European laws or directives with

respect to safety, health, environment and consumer protections.

Note: Full M3500A specifications are included in Appendix A.

1.7 Inspection

Your product package is supplied with the following items:

z One M3500A Multimeter unit. (224mm x 113mm x 373mm, approx.

4.3 Kg)

z One power line cord. z One USB cable.

z Standard Test Leads

z One CD (including this electronic User's Manual and software

applications).

z Optional accessories as you ordered. z Multi-Point scanner card. (Optional) z GPIB interface card. (Optional)

1. The M3500A is provided with a Standard Test lead set, described below.

Test Lead Ratings:

IEC 61010-031 CAT III

Operating Voltage: 1000V DC

Current: 10 Ampers

UL/CE Rated

Material:

Probe Body: Outer Insulation-Santoprene Rubber.

Banana Plug: Body Brass, Nickel Plated Spring Beryllium Copper, Nickel Plated.

Insulation: Polypropylene Resin Flasme Retardant Grade 2038.

Others

If any part of the Test Lead Set is damaged, please do not use and replace with

a new set.

※ Warning: If users use the Test Lead Set without following the

specification of Picotest Corp., the protection of the Test Lead Set could

be impaired. In addition, please don’t use a damaged Test Lead Set

against the instrument break or personal injury.

1.8 Options and Accessories

The following options and accessories are available from PICOTEST for

use with the Model M3500A. Please refer to the following Table 1-1.

Table 1-1

Part Name Part Number

Multi-point Scanner Card M3500-opt01

Thermocouple adapter M3500-opt02

Adapters (Banana to BNC Adapter) M3500-opt03

GPIB Card M3500-opt04

RTD Probe Adapter M3500-opt05

RS232 Adapter M3500-opt06

Kelvin Probe M3500-opt07

1.9 M3500A’s Dimension

Please get the dimension’s information in the following different ways.

1. The dimension without the handle and the front & Rear Bumpers is in

the following Picture 1. (LxWxD - 213.6x88.6x370 mm)

2. The dimension with the handle and the front & Rear Bumpers is in the

following Picture 2. (LxWxD - 255x113x373 mm)

3. The dimension with the front & Rear Bumpers, but without the handle

is in the following Picture 3. (LxWxD - 224x113x373 mm)

2 Overview

This chapter will give you an overview of M3500A’s basic features and

guide you through the basics of M3500A digital multimeter. Users will

become familiar with those features after reading this chapter.

2.1 Setting up Your M3500A Digital Multimeter

The purpose of this section is to prepare users for using M3500A DMM.

You may want to check if you have all the parts with your multimeter. All

our products are handled and inspected professionally before shipping

out to our customers. If you find any damaged or missing parts, please

contact your local service representative immediately and do not

attempt to operate the damaged product. If users have any doubt about

their products, they are encouraged to contact their local service

representative.

2.1.1 To adjust the handle

You may adjust the carrying handle to suit your needs. The following

figures show you how to adjust the handle.

I. Taking off the handle from the Multimeter

【Step 1】(Turn up the handle)

Pull slightly outward on both sides of the handle and slowly rotate it up as

shown in Figure 1-1.

Figure 1-1

【Step 2】(Pull out the handle)

When the handle is turned up to 90° with the multimeter please pull out

the handle from the multimeter as shown in Figure 1-2.

Figure 1-2

Ⅱ. Adjusting the position for your convenience

Here are some example positions to suit users’ needs.

【Position 1】

The default position is for packing as shown in Figure 1-3。

Figure 1-3

【Position 2】

The adjusted position is for operation as shown in Figure 1-4。

Figure 1-4

【Position 3】

The carrying position is with the handle as shown in Figure 1-5。

Figure 1-5

2.1.2 To connect the power

Check the power-line voltage on the rear panel to see if voltage setting is

correct for your area. Change the setting if it is not correct or the fuse is

broken. Please follow the steps below.

2.1.2.1 To convert the voltage

Warning! In some areas, the power supplied voltage is 240V or

120V; in others, the power supplied voltage is 220 V or 100 V. Please

refer to your local power supplied voltage to see if you have the right

setting.

Warning! Before changing the setting, make sure the multimeter is

disconnected from the AC power. An incorrect voltage setting may cause

severe damage to your instrument.

Warning! The power cord supplied with M3500A contains a

separate ground wire for use with grounded outlets. When proper

connections are made, instrument chassis is connected to power line

ground through the ground wire in the power cord. Failure to use a

grounded outlet may result in personal injury or death due to electric

shock.

Suppose your condition is in AC 100V and you want to convert the

voltage to the 220V. Follow these steps to change the voltage setting.

【Step 1】

Verify that the meter is disconnected as shown in Figure 2-1.

Figure 2-1

【Step 2】

Open the voltage setting selector cap as shown in Figure 2-2. (You

might need a screwdriver to do so.)

Figure 2-2

【Step 3】

Remove the red voltage setting selector from the right middle seam as

shown in Figure 2-3. (You might need a screwdriver to do so.)

Figure 2-3

【Step 4】

Turn it over to 220V position as shown in Figure 2-4.

Figure 2-4

【Step 5】

Insert the voltage setting selector back into the socket and close the cap

as shown in Figure 2-5.

Figure 2-5

2.1.2.2 To change the fuse

Warning! Before replacing the power-line fuse, make sure the

multimeter is disconnected from the AC power. You must be a qualified

personnel to perform this action.

Warning! For continued protection against fire or instrument

damage, only replace fuse with the same type and rating. If the

instrument repeatedly blows fuses, locate and correct the cause of the

trouble before replacing the fuse.

Verify that the power-line fuse is good. Replace the fuse if it is damaged.

Use only the same type and same rating fuse noted on the rear panel.

Please follow the steps below to change the fuse.

【Step 1】

Verify that the meter is disconnected as shown in Figure 2-6.

Figure 2-6

【Step 2】

Open the voltage setting selector cap as shown in Figure 2-7. (You

might need a screwdriver to do so.)

Figure 2-7

【Step 3】

Remove the red voltage setting selector from the right middle seam as

shown in Figure 2-8. (You might need a screwdriver to do so.)

Figure 2-8

【Step 4】

Remove the broken fuse from the selector as shown in Figure 2-9.

Figure 2-9

【Step 5】

Replace with the new fuse as shown in Figure 2-10.

Figure 2-10

【Step 6】

Insert the voltage setting selector back into the socket and close the cap

as shown in Figure 2-11.

Figure 2-11

【Step 7】

Make sure the power switch on the front panel is in “Power OFF”

condition before plugging as shown in Figure 2-12.

Figure 2-12

Power switch:

“POWER OFF”

【Step 8】

After finishing the above procedures, you can plug in your power cord as

shown in Figure 2-13.

Figure 2-13

【Step 9】

Press on the power switch on the front panel for activating M3500A as

shown in Figure 2-14.

Figure 2-14

Power switch:

- “POWER ON”

2.1.3 Factory Default When Power-ON

Table 2-1 shows the factory default of M3500A.

Table 2-1

Function Default

Function DCV

Autozero On

Frequency and Period Source AC Voltage

Output Format ASCII

Ratio Off

Bandwidth

Input

20Hz

Frequency

AC Digits 5.5

Voltage

Current

Frequency

and Period

Slow 5.5

DC digits

(1 PLC)

Range Auto

AC Digits 5.5

Slow 5.5

DC Digits

(1 PLC)

Range Auto

Digits 5.5

Range AUTO

Medium

Rate

(100ms)

Digits 5.5

Diode Test

Resistance

(2-wire)

Temperature

Triggers

Input Resistance 10MΩ

Range 1mA

Rate 0.1 PLC

Slow 5.5

Digits

(1 PLC)

Range Auto

Slow 6.5

Digits

(10 PLC)

Thermocouple Universal Type

Source Immediate

Delay Auto

2.2 Features

z Resolution: 6.5 digits. z 5*7 dot matrix VFD, dual displays with 3-color annunciators. z 11 standard measurement functions & 8 math functions. z

4 front ground terminal are connected to Chassis.

z Stability, Accuracy and Speed (2000RDGS/Sec at 4.5 Digit, 50

RDGS/Sec at 6.5 Digit in 60 Hz)

z Multi-Points Scanner Card: Up to 10 Channels. (Optional) z RTD probe Adapter (optional) convenient to use. z Built-in USB and GPIB (Optional) Interfaces. z Easy & Free PC applications.

2.3 M3500A Function Introduction

For users to become familiar with the M3500A DMM, we will give a brief

introduction to the basic operations of M3500A DMM. There are three

major parts of M3500A: (2.3.1) the front panel, (2.3.2) the display,

and (2.3.3) the rear panel. We will discuss each of them in the

following sections.

2.3.1 The Front Panel

There are different buttons and terminals on the front panel. They are

divided into the following groups: (DISPLAY & POWER), (FUNCTION,

MATH, TRIGGER, MEMORY, SETUP, RANGE, INPUT TERMINALS), and

(FILTER, DIGITS, LOCAL, and SHIFT) as shown in Figure 2-15.

Figure 2-15

1. Power & Display:

z Power: Activates M3500A DMM. z Display: Shows model, version & condition by pressing round PREV

& NEXT buttons.

2-1. First row without SHIFT button:

z DCV: Selects DC voltage measurement. z ACV: Selects AC voltage measurement.

z Ω2: Selects 2-wire resistance measurement. z FREQ: Selects frequency measurement. z CONT: Selects the continuity test. z TEMP: Selects RTD temperature measurement.

2-2. First row with SHIFT button:

z DCI: Selects DC current measurement. z ACI: Selects AC current measurement. z Ω4: Selects 4-wire resistance measurement. z PERIOD: Selects period measurement.

z z TCOUPL: Selects thermocouple temperature measurement.

2-3. Second row without SHIFT button:

z FILTER: Enable or disable the digital filter.

: Selects diode testing.

z DIGITS: Changes resolution. z RATIO: Enables the dcv:dcv ratio function. z %: Calculates the ratio to a target value in percentage. z MIN/MAX: Captures the minimum or maximum readings from the

measurement.

z NULL: Activates the offset function in order to get the real measured

reading.

2-4. Second row with SHIFT button:

z STEP: Scans from a channel to the next channel in delayed action

when using the scanner card.

z SCAN: Enables scanning function when using the scanner card. z LIMITS: Used for Setting upper and lower limit values for readings. z MX+B: Used for calculating slope. X is the normal display reading. M

and B are constants specified by user for scale factor and offset.

z dBm: Used for displaying voltage measurement in dBm power unit. z dB: Used for displaying voltage measurement in decibel unit.

2-5. Third row without SHIFT button:

z SINGLE: Manually triggers the multimeter to make measurements. z AUTO TRIGGER: Instructs the multimeter to make measurements

continuously.

z STORE: Stores a specified number of subsequent readings. z RECALL: Displays stored readings and buffer statistics. Use ◁▷ or

△▽ searching buttons to toggle between reading number and

reading.

z LOCAL: Cancels USB or GPIB remote mode. z SHIFT (in blue): Used for accompanying other button with upper print

in blue and converting function.

2-6. Third row with SHIFT button:

z EXTRIG: Selects external triggers as the trigger source via BNC port

on the rear panel.

z HOLD: Holds reading.

3-1. The first row in SETUP section

z ◁▷: Scrolls through buffer, conceals or reveals the digits while

measuring.

3-2. The second row in SETUP section:

z ESC: Cancels selection, moving back to measurement display. z ENTER: Accepts selection, moving to next choice or back to

measurement display.

z LOCK: Presses SHIFT then ESC button to prevent unpredictable

operation on the panel. In order to release lock condition, please

press ESC again.

3-3. The third row in SETUP section:

z CONFIG: Offers setting or adjusting function, relating some front

panel buttons.

z MENU: Offers setting or adjusting function, not relating other front

panel buttons.

4. RANGE:

z △: Moves to higher range. z ▽: Moves to lower range. z AUTO: Enables or disables auto-range.

5. Terminals: Selects input signal connections on front or rear panel.

6. Inserted Connections & Fuse Device:

z 4 Chassis Ground Connections: Separate environmental noises. z HI & LO: Used for all measurements, except DC and AC current.

(Maximum input voltage: 1000V for voltage measurements. 200V for

4-wire measurement)

z LO & I: Used for making DC and AC current measurements. z Front Fuse: Secures your Meter against damage of strong current pulse.

(Maximum current: 3A, 250V)

7. Chassis Ground Terminal:

z The chassis ground terminal is used for shielding the noise from the

nature, especially when users want to get a very small signal via the

application of a BNC-to-Banana Adapter. Please refer to the Figure

2-16.

Figure 2-16

2.3.2 The Display

M3500A has a 5x7 dot matrix, dual-display with three-color (White, Red

and Yellow) annunciators for a better view. There are two rows in the

dual-display screen. The upper row displays readings and units. A

maximum 13 characters are allowed for upper row dot-matrix display.

The lower row displays range of the measurements, condition or

information about an ongoing configuration. A maximum 16 characters

are allowed for lower row dot-matrix display. There are additional

annunciators at upper side and right side of the display screen for

indicating the state or the condition of an ongoing measurement. They

are explained individually in the following sections.

Upper Row Display

Lower Row Display

Figure 2-17

2.3.2.1 Annunciators at Upper Side

Figure 2-18

z ADRS: Indicates the multimeter is controlled via GPIB Interface. z RMT (REMOTE): Indicates the remote state. (USB Interface) z MAN: Indicates the manual range is taken. z TRIG: Shows the single triggering is enabled. z HOLD: Indicates reading hold function is enabled. z MEM: Indicates the using of internal memory. z RATIO: Indicates the dcv:dcv ratio operation. z MATH: Indicates the “MATH” operation is taken. z ERR: Error occurs. z SHIFT: Indicates SHIFT button is pressed. z REAR: The rear panel input terminal is selected for the measurement. z FILT: The digital filter is started.

2.3.2.2 Annunciators at Right Side

z 4W: Indicates 4 –wire mode is selected for resistance measurement.

●)

)

z z

z CW: Not used for Model M3500A. z CC: Not used for Model M3500A. z CV: Not used for Model M3500A. z EXT: Indicates the External Trigger Mode is enabled. z LOCK: Indicates the front panel menu operation

z OVP: Not used for Model M3500A. z OCP: Not used for Model M3500A. z OFF: Indicates the front panel display is turned off. Figure 2-19

): Indicated the continuity testing is enabled.

: Indicates the diode testing operation is taken.

is locked.

2.3.3 The Rear Panel

3 4 5

The rear panel of the M3500A is shown in Figure 2-20. This figure

includes important abbreviated information that should be reviewed

before using the instrument.

1. Inserted Connections & Fuse Device:

z HI & LO: Used for all measurements, except AC & DC current and

temperature.

z LO & I: Used for making DC and AC current measurements. z Rear Fuse: Secures your Meter against damage of strong current

pulse.

Figure 2-20

2. BNC Connections:

z VM COMP: Voltmeter Complete Output Terminal. Outputs a low-true

pulse after the completion of each measurement.

z EXT TRIG: External Trigger Input Terminal. Inputs a low-true pulse

from a remote interface.

3. USB Connection: Connects a remote computer for changing

operation environment instead of the front panel control.

4. Protective Conductor Terminal.

5. Power Module: Contains the AC line receptacle, power line fuse, and

line voltage setting. Configured for line voltages of 100/220V or

120/240V. (Depend on the power utility in your area.)

6. Option Slot: Designed for installing an optional multi-point scanner

card (Model: M3500-opt01).

7. Option GPIB/IEEE488 Connection: Connects a remote computer

with an IEEE488 cable for changing operation environment instead of

the front panel control (Model: M3500-opt04).

3 Basic Measurement Function

This chapter introduces some basic measurement functions in M3500A.

You will learn how to use your M3500A multimeter to measure voltage,

current, resistance, frequency, period, continuity, diode and

temperature in this chapter.

3.1 Voltage Measurements (DC & AC)

The ranges for DC voltage measurements in M3500A are 100mV, 1V,

10V, 100V and 1000V. For AC voltage measurements, the ranges are

100mV to 750V AC-Coupled

show the locations of the buttons needed and message display for

voltage measurement. Figure 3-3 shows the location of the input

terminals on the rear panel.

Warning: Do not apply more than 1000V (peak) to the multimeter.

Applying excess voltage may damage your meter, or cause possible

electric shock or personal injury.

※ Note: To eliminate the thermal EMFs due to the differences between

two metals, use copper leads to connect your source signal to the meter.

How to measure voltage

① Selects input signal connections on front or rear panel. ② Connect the test leads to the terminals as shown in Figure 3-1(DC)

TRMS, or 1000V peak. Figures 3-1 and 3-2

or Figure 3-2 (AC).

③ Set RESOLUTION of DCV (Refer to 4.1.3), BAND WIDTH of ACV (Refer

to 4.1.2.1) or skip this step if default is to be used.

④ Press DCV or ACV button for DC or AC voltage measuring. ⑤ Select the auto-range function by pressing AUTO button on the front

panel or use △ ▽ buttons to select desired range.

⑥ Connect test leads to your source signal and observe the reading

shown on the display. If the input signal is beyond the allowed range,

an overflow message “OVLD” will be displayed.

Figure 3-1

Figure 3-2

※ Note: The rear panel terminals can also be used via the same

procedures as the front panel terminals. (Refer to Figure 3.3)

Figure 3-3

3.2 Current Measurements (DC & AC)

The ranges for DC current measurements in M3500A are 10mA, 100mA,

1A and 3A. For AC current measurements, the range is 1A with a

sensitivity of 1 μA to 3A AC-Coupled TRMS with a sensitivity of 10μA.

Figure 3-4 and 3-5 show you how to measure DC/AC currents in

M3500A.

Warning! The maximum input current allowed is 3A, 250V. Do not

apply excess current to your meter to avoid damaging the fuse of current

input.

※ Note: To eliminate the thermal EMFs due to the differences between

two metals, use copper leads to connect your source signal to the meter.

How to measure current

① Selects input signal connections on front or rear panel. ② Connect the test leads to the terminals as shown in Figure 3-4. ③ Set RESOLUTION of DCI (Refer to 4.1.3), BANDWIDTH of ACI (Refer

to 4.1.2.1) or skip this step if default is to be used.

④ Press SHIFT+DCV or SHIFT+ACV buttons for DCI or ACI

measurement.

⑤ Select the auto-range function by pressing AUTO button on the front

panel or use △ and ▽ buttons to select desired range.

⑥ Connect test leads to your source signal and observe the reading

shown on the display. If the input signal is greater than the allowed

range, an overflow message “OVLD” will be displayed.

Figure 3-4

※ Note: The rear terminal panel also can be used via the same

procedures as the front panel. (See Figure 3-5)

Figure 3-5

3.3 Resistance Measurements (2 & 4-wire)

The ranges for resistance measurement are 100 Ω, 1KΩ, 10kΩ, 100kΩ,

1MΩ, 10MΩ, and 100MΩ, with a sensitivity of 100 μΩ (on 100 Ω range.)

There are two modes for measuring the resistance: 2-wire mode as

shown in Figure 3-6 and 4-wire mode as shown in Figure 3-7. With

4-wire mode, the test current is measured from the test resistance

through one pair of the test leads, and the test voltage across the

resistance under test is measured from another set of the test leads. As

a result, the 4-wire mode is more accurate for low resistance

measurements. The trade off is the longer settling time for 4-wire mode.

Figure 3-8 and 3-9 show the input terminal connections on the rear

panel for 2-wire mode and 4-wire mode respectively.

How to measure resistance

① Selects input signal connections on front or rear panel. ② Connect the test leads to the terminals as shown in Figure 3-6

(2-wire) or Figure 3-7 (4-wire).

③ Set RESOLUTION (Refer to 4.1.3) or skip this step if default is to be

used.

④ Press Ω2 button for 2-wire measurement or SHIFT + Ω2 buttons for

4-wire measurement.

⑤ Select the auto-range function by pressing AUTO button on the front

panel or use △ and ▽ buttons to select the desired range.

⑥ Connect test leads to your source signal and observe the reading

shown on the display. If the input signal is greater than the allowed

range, an overflow message “OVLD” will be displayed.

Figure 3-6

Figure 3-7

※ Note: The rear terminal panel also can be used via the same

procedures like the front panel as shown in Figures 3-8 and 3-9.

Figure 3-8

Figure 3-9

3.4 Frequency & Period Measurements

M3500A uses an on-board counter with 25MHz to measure the frequency

(period). The measurement band is from 3Hz to 300kHz (or 333 ms to

3.3 μs) and the measurement voltages range from 100mV to 750 V in

AC. The default for “RANGE” is auto-range.

Warning! The maximum input allowed is 1000V. Applying excess

voltage may damage your meter.

How to measure frequency and period

① Selects input signal connections on front or rear panel. ② Connect the test leads to the terminals as shown in Figure 3-2. ③ Set RESOLUTION (Refer to 4.1.1) and INPUT JACK. Or skip this step

if default is to be used.

④ Press FREQ button for frequency measurement or SHIFT + FREQ

buttons for period measurement.

⑤ Select the auto-range function by pressing AUTO button on the front

panel or use △ and ▽ buttons to select the desired range.

⑥ Connect test leads to your source signal and observe the reading

shown on the display. If the input signal is beyond the allowed range,

an overflow message “OVLD” will be displayed.

※ Note: The rear terminal panel also can be used via the same

procedures as the front panel. (Please refer to Figure 3-3)

3.5 Continuity Measurements

M3500A uses 1 K Ω range for the continuity measurement. The meter

beeps when the test resistance is less than the threshold resistance. The

default threshold resistance is 10Ω, but user can set the threshold

resistance to anything between 1 Ω and 1 K Ω. The resistance value set

by user is stored in a volatile memory and will be cleared after the meter

has been turned off. The source current for the continuity measurement

is 1 mA.

Warning! The maximum input voltage allowed is 1000 V. Applying

excess voltage may damage the meter and cause unpredictable

hazards.

How to measure the continuity

Selects input signal connections on front or rear panel.

① Connect the test leads to the terminals as shown in Figure 3-2. ② Set REConnect the input signal as the following figure. ③ Set threshold resistance via pressing CONFIG + CONT buttons. (Or

skip this step if default resistance is to be used) When ready, press

ENTER button.

④ Press CONT button. ⑤ The measured value will be shown on the display automatically. Meter

“beeps” when measured resistance value is lower than threshold

value.

Figure 3-10

3.6 Diode Measurements

M3500A uses a current source of 1 mA for diode testing. The maximum

resolution is 10 μV on a fixed range of 1 V DC. The default threshold

voltage is fixed between 0.3 and 0.8 volts and the reading rate is fixed at

0.1 PLC (The voltage bound is adjustable from 0.01V up to 1.2V.). A

“Beep” sound will appear when the diode measured value is in the range.

Warning! Positive end of the source signal is to be cennected to HI

of the input terminals, and the negative end to LO of the input terminals.

How to measure diode

① Selects input signal connections on front or rear panel. ② Connect the diode to the terminals. For forward bias, connect the

probe from input terminal “HI” to the positive end of the diode, and

connect the probe from input terminal “LO” to the negative end of the

diode.

③ Set voltage bound via pressing CONFIG + SHIFT + CONT buttons.

When ready, press ENTER. (Or skip this step if you wish to use the

default voltage bound.)

④ Press SHIFT + CONT buttons to select the diode testing function and

observe the reading on the display.

Figure 3-11

3.7 Temperature Measurements

The M3500A supports thermocouples and resistance temperature

detector (RTD) types of probes. For thermocouples, M3500A supports 7

types: E, J, K, N, R, S and T. Please refer to Table 3-1 for their

temperature ranges. Be sure that the temperature function is configured

for the right sensor type before making measurements (Refer to 4.1.8

for how to make the sensor configuration).

In general, RTDs have a better accuracy and long-term stability than

thermocouples. The default RTD type in M3500A is PT100 and the

thermocouple is type K.

Table 3-1

Sensor Type Temperature

Range(°C)

E -270~1000 -518~1832

J -210~1200 -140~2192

K -270~1372 -518~2502

N -270~1300 -518~2372

R -50~1768 -122~3236

S -50~1768 -122~3236

T -270~400 -518~752

RTD (PT 100) -200~850 -392~1562

Temperature

Range(°F)

3.7.1 Thermocouple Measurements

Connect the thermocouple adapter to the banana jacks on the front

panel. The difference between each type is subject to the patch thermal

leads.

※ Note: Only connection via the front panel can be used for temperature

measurements.

How to measure thermocouple

① Use terminals switch to select terminals on the front panel. ② To measure thermocouple must be via thermocouple adapter and the

low thermal patch leads as shown in Figure 3-12. (When the

mentioned modules are well connected as the following figure, please

go to the next step.)

③ Configure the thermocouple type and unit using CONFIG + SHIFT +

TEMP, such as K TYPE and ºC. When ready, press ENTER button.

④ Press SHIFT + TEMP buttons. ⑤ Take the reading on the display.

Figure 3-12

3.7.2 RTD Measurements

There are three kinds of temperature measurements with RTDs: 2-wire,

3-wire and 4-wire measurements. You will find connection instructions

and measuring procedures in the following sections.

3.7.2.1 2-Wire RTD Measurements

2 3

How to measure temperature with 2-Wire RTD

The following Figure 3-13 shows theory diagram of 2-Wire RTD

measurement.

① Use terminals switch to select front terminals. ② Insert a specified adapter into the front terminals. Connect the low

thermal patch leads to the adapter as shown in Figure 3-14.

③ Configure sensor type and unit using CONFIG + TEMP and ◁ or ▷.

When ready, press ENTER button.

④ Press TEMP button. ⑤ Place RTD in the desired position and take the reading on the display.

Figure 3-13

Figure 3-14

3.7.2.2 3-Wire RTD Measurements

How to measure temperature with 3-Wire RTD

The following Figure 3-15 shows theory diagram of 3-Wire RTD

measurement.

① Use terminals switch to select front terminals. ② Insert a specified adapter into the front terminals. Connect the low

thermal patch leads to the adapter as shown in Figure 3-16.

③ Configure sensor type as you would be with 4-wire RTD and unit using

CONFIG + TEMP and ◁ or ▷. When ready, press ENTER button.

④ Press TEMP button. ⑤ Place RTD in the desired position and take the reading on the display.

※ Note: When users do the 3-wire RTD measurement the input LO and

sense LO have to be connected in short condition.

※ Note: “Source” means RTD Probe or RTD Simulator.

In Short Condition

Figure 3-15

In Short Condition

Figure 3-16

3.7.2.3 4-Wire RTD Measurements

How to measure temperature with 4-Wire RTD

The following Figure 3-17 shows theory diagram of 4-Wire RTD

measurement.

① Use terminals switch to select front terminals. ② Insert a specified adapter into the front terminals. Connect the low

thermal patch leads to the adapter as shown in Figure 3-18.

③ Configure sensor type and unit using CONFIG + TEMP and ◁ or ▷.

When ready, press ENTER button.

④ Press TEMP button. ⑤ Place RTD in the desired position and take the reading on the display.

1 2 3

Figure 3-17

Figure 3-18

4 Front Panel Operations

This chapter contains information about how to change the parameters

and settings for your measurements and all the details about each

feature and function.

4.1 Measurement Configuration

The following information will guide you through ways to configure

measurement functions. It provides you the flexibility to change any

parameter in any measurement function when needed, including ADC

setting, filter, resolution setting (digits), DC input resistance, threshold

resistance (continuity), range (manual & auto), rate (integration time),

sensor type for temperature measurements, remote interface selection

and input terminal switch.

4.1.1 Set ADC (Auto Zero & Auto Gain)

Zero and Gain

The purpose of Auto Zero and Auto Gain functions are used for

minimizing the offset influence on your measurements. When Auto Zero

or Auto Gain is enabled, M3500A takes the input signal reading as a base

value and then internally disconnects the input signal, and takes a offset

reading (a null offset). It then subtracts the offset from the base to get

an accurate measurement.

Displayed reading = Base value (input signal) – Offset value

When the Auto Zero or Auto Gain is enabled the meter takes an offset

reading for each subsequent measurement. However, when Auto Zero or

Auto Gain is disabled, the meter only takes one offset reading each time

when you change the function settings. User can set “PERIOD” to change

the time interval for taking an offset reading.

Defaults

The default settings for Auto Zero and Auto Gain are enabled. The user

selected values for Auto Zero and Auto Gain are stored in a volatile

memory and the default settings will be restored when the meter is

power-off.

How to set Auto Zero and Auto Gain

You can change the Auto Zero and Auto Gain setting through the front

panel or through the remote interface operation.

Front Panel Operation

The following steps show how to set Auto Zero and Auto Gain directly

through the front panel.

Be aware that Auto Zero setting is always affected by the resolution

setting. Whenever the resolution is altered, Auto Zero may be changed

accordingly. The relation between resolution and Auto Zero is shown in

Table 4-1.

Press MENU and then ENTER on SET ADC. If “SET ADC” is not shown on

the display, use ◁ and ▷ buttons to locate it. Press ENTER on ZERO or

GAIN. Again, use ◁ and ▷ buttons to locate it if it is not shown on the

display. Press ENTER on AUTO ZERO or AUTO GAIN option and then use

◁ and ▷ to the “ON” or “OFF”. Press “ENTER” by your choice. The

locations of these buttons are shown with red rectangle frames in Figure

4-1.

Procedures: MENU→SET ADC → ZERO→ AUTO ZERO {ON|OFF}

MENU→SET ADC → GAIN→ AUTO GAIN {ON|OFF}

Table 4-1

Auto

Integration

Resolution

Zero

Gain

Time(PLC)

Fast 4 ½ digits Off Off 0.02

Slow 4 ½ digits On On 0.1

Fast 5 ½ digits Off Off 0.1

Slow 5 ½ digits On On 1

Fast 6 ½ digits On On 1

Slow 6 ½ digits On On 10

※ Note: To change resolution, refer to Section 4.1.3: Resolution Setting

in this chapter.

Figure 4-1

Remote Interface Operation

To set Auto Zero and Auto Gain through the remote interface, use the

following commands:

SENSe:ZERO:AUTO {OFF|ONCE|ON}

SENSe:GAIN:AUTO {OFF|ONCE|ON}

The OFF and ONCE parameters have a similar effect. Auto Zero OFF or

Auto Gain OFF doesn’t issue a new offset measurement. However, Auto

Zero ONCE or Auto Gain ONCE issues an immediate offset measurement.

4.1.2 Filter

Filter is used to remove noises in measurement readings. M3500A is

equipped with two types of filters: AC filter and digital filter. AC filter is

for AC measurements only. It also affects the speed of the multimeter

to yield a measurement reading. Digital filter further stabilizes the

measurement readings by averaging. Both of them are described in

detail in the subsequent sections respectively.

4.1.2.1 AC Filter

Definition:

User is allowed to set the bandwidth for selecting one of the three AC

filters (Slow, Medium and Fast), in order to achieve either higher

accuracy in low frequency measurements or faster AC settling time.

Defaults

The factory default is 20 Hz (Medium). Users can select their filter type as

they wish when setting bandwidth value. The selection is stored in a

volatile memory and the default setting will be restored when the meter

is power-off.

Table 4-2

Time

Bandwidth AC Filter

( seconds per reading)

3 Hz ~ 300 KHz S l o w 7

20 Hz ~ 300 KHz Medium 1

200 Hz ~ 300 KHz Fast 0.1

How to set AC Filter in AC measurements:

User can set the AC Filter either through the front panel operation or

through the remote interface operation.

Front Panel Operation

Press CONFIG + ACV button. Use ◁ and ▷ buttons to locate “BAND

WIDTH” submenu, and then press ENTER to select it. Look for the desired

bandwidth using ◁ and ▷ buttons. Then press ENTER on your

selection. There are three options: 3Hz, 20Hz and 200Hz. The locations

of these buttons are shown with red rectangle frames in Figure 4-2.

Figure 4-2

Remote Interface Operation

From your PC terminal, use the following command to specify the filter

type:

DETector:BANDwidth {3|20|200|MIN|MAX}

4.1.2.2 Digital Filter

Definition:

M3500A uses an averaging digital filter to yield a reading for display from

a specified number of measurement readings in the past. The past

measurement readings are stored in a stack of memory. The number

may be in the range of 2 to 100. User may select one of the two modes

of digital filter operations: Moving Average and Repeating Average.

The moving average filter puts the specified number of reading

conversions in a first-in, first-out order. The very first measurement

reading simply fills up the stack. To yield a reading for display, the filter

produces an average of the stacked measurement readings every time a

new measurement reading is available and replaces the oldest reading in

the stack. In the repeating average mode, the multimeter waits for the

measurement reading stack to fill up and then take an average to

produce a reading for display. It then flushes the stack and starts over

with an empty stack. Consequently, the repeating digital filter yields one

reading for display every specified number of measurement readings.

Digital filter is not available for diode, continuity, frequency and period

measurements.

Default

The digital filter is enabled and is in moving average mode with 10

readings by default.

How to enable/disable digital filter

Press FILTER button to switch the digital filter function. The “FILT”

anunnciator indicates the state of the digital filter. When it is lit, the filter

is enabled.

How to configure digital filter:

You can configure the digital Filter either through the front panel

operation or through the remote interface operation.

Front Panel Operation

For READINGS setting, please press CONFIG and then FILTER button for selecting READINGS. Press ENTER to access. Use ◁, ▷, △ and ▽

buttons to set the READINGS (from 2 to 100) in order to get an average

value. Press ENTER when it’s ready.

For MODE setting, please press CONFIG and then FILTER button for

selecting MODE. Press ENTER to access. Use ◁, ▷ to select MOVING AVG.

or REPEAT AVG.. Please ENTER to confirm.

Press FILTER button to enable or disable this function.

Remote Interface Operation

Use the following commands to set your digital filter:

SENSe:AVERage:TCONtrol {MOVing|REPeat}

SENSe:AVERage:TCONtrol?

SENSe:AVERage:COUNt {<value>|MINimum|MAXimum}

SENSe:AVERage:COUNt? [MINimum|MAXimum]

SENSe:AVERage:STATe {OFF|ON}

SENSe:AVERage:STATe?

4.1.3 Resolution Setting (Digits)

Definition

Resolution is the number of digits a multimeter can measure. User can

select the resolution for a specific measurement. The choices for the

resolution setting are: fast 4.5, slow 4.5, fast 5.5, slow 5.5, fast 6.5 and

slow 6.5. For a higher accuracy, user can select 6.5 digit resolution. For

a faster measurement, user can select 4.5 digit resolution.

The resolution setting applies to all math operations under the selected

measurement function. The selected value is stored in a volatile memory

and the setting is only valid for the current measurement function. User

can select different resolution for different measurement function.

Default

The default value for the resolution is slow 5.5 digit and the default value

will be restored when the meter has been turned off or after a remote

interface reset. The user selected value for the resolution setting is

stored in a volatile memory and the setting is only valid for the current

measurement function. Please refer to Table 2-1 on page 24.

※ Note: The resolution setting for AC measurements is actually fixed at

6 ½ digits. When user selects a lower resolution, the meter will mask out

the extra digits. User’s selection of resolution for AC function will not

affect the actual speed or accuracy.

How to set the resolution

The resolution can be set either through the front panel or the remote

interface operation.

Front Panel Operation

There are two ways to set the resolution. The locations of the buttons are

shown with red rectangle frames in Figure 4-3.

z First select your desired measurement function by pressing one of the

function buttons located on the first row of your meter's front panel.

z Press DIGITS button to select your desired resolution for your

measurement. User can press DIGITS button several times to see

how the resolution setting changes from 4.5, 5.5 to 6.5.

※ Note: When using Method A to set the resolution, your options are 4.5

(slow), 5.5 (slow) and 6.5 (fast).

z Press CONFIG and then select a function as you wish from DCV, DCI

(SHIFT +DCV), Ω2, Ω4 (SHIFT + Ω2), FREQ and PERIOD (SHIFT +

FREQ).

z Press ENTER on RESOLUTION submenu. If it is not shown on the

display, use ◁ and ▷ to locate it.

z Use ◁ and ▷ to find your desired resolution. Press ENTER on your

choice.

※ Note: The resolution of AC measurements is fixed at 6.5 digit.

※ Note: The options for frequency and period measurements are 4.5

(slow), 5.5 (slow) and 6.5 (slow).

Figure 4-3

Remote Interface Operation

Use the following commands on your PC terminal to set the resolution for

your measurement.

CONFigure:<function> <range>,<resolution>

MEASure:<function>? <range>,<resolution>

SENSe:<function>:RESolution <resolution>

Users can specify the resolution in the same units as the measurement

function, not in number of digits. For instance, specify the resolution in

vots and the frequency in hertz. The examples are in the following.

CONF:VOLT:DC 10,0.001 (4 1/2 digits on the 10 Vdc range)

MEAS:CURR:AC? 1,1E-6 (6 1/2 digits on the 1 A range)

CONF:FREQ 1 KHz,0.1 Hz (1000 Hz input, 0.1 Hz resolution)

VOLT:AC:RES 0.05 (50 mV resolution on the ac function)

4.1.4 DC Input Resistance

Definition

To reduce the effect of loading errors due to the input resistance,

M3500A allows user to select a much larger input resistance (> 10G Ω)

for low input DC voltage (100mV, 1V and 10V) measurements. This

feature is only available for DC voltage measurements and it is not

applicable to other measurement functions.

Default

The default input resistance for all measurements is 10M Ω. Please refer

to Table 2-1 on page 24. The DC input resistance can only be changed

for measurements with 100mV, 1V or 10V range. For 100V DCV, 1000 V

DCV and other measurement functions, the input resistance is fixed at

10M Ω and can not be changed. Also note that the user selected value

is stored in a volatile memory. The default setting will be restored after

the meter has been turned off.

How to set the DC input resistance

You can set the DC input resistance either through the front panel

operation or through the remote interface operation.

Front Panel Operation

Press CONFIG + DCV , and then use ◁ and ▷ buttons to locate “INPUT

R” option. Press ENTER to select it. Then select desired value for the

input resistance by pressing ◁ or ▷ button. Press ENTER to choose it.

Two values are available: 10M Ω or > 10G Ω. The locations of these

buttons are shown with red rectangle frames in Figure 4-4.

Figure 4-4

Remote Interface Operation

The automatic input resistance mode can be enabled / disabled. With

AUTO OFF (default), the input resistance is fixed at 10MΩ for all ranges.

With AUTO ON, the input resistance is set to >10GΩ for the three lowest

DC voltage ranges (100mV, 1V and 10V). Use the following command

from your PC terminal to disable the auto input DC resistance setting

(the result is a fixed input DC resistance at 10M Ω for all

measurements.)

INPut:IMPedance:AUTO {OFF | ON}

4.1.5 Threshold Resistance (Continuity)

Definition

When testing continuity, the beeper goes off when the measured

resistance is less than the threshold resistance. The threshold resistance

can be set to any value between 1Ω and 1000Ω.

Default

The factory default for continuity threshold resistance is 10Ω. User’s

selection is stored in a volatile memory and the default value will be

restored after the meter has been turned off.

How to set the threshold resistance

User can change the threshold resistance only through the front panel.

Press CONFIG button and then CONT button. Use ◁ and ▷ buttons to

move through the digits and lower or increase the number to your desired value using △ and ▽ buttons , then press ENTER button to set

the value. The locations of these buttons are shown with red rectangle

frames in Figure 4-5.

Figure 4-5

4.1.6 Range (Manual & Auto)

Definition

When making measurements except CONT, DIODE and Temperature,

you can let the machine choose ranges for you, or you can select the

appropriate ranges manually by yourself. The difference between

auto-range and manual-range is the settling time. Auto-range is a

convenient way for user, but manual-range can usually speed up the

process.

If the input signal is beyond allowed range, an “OVLD” message will be

shown on the display. The thresholds of maximum/minimum readings

for each range are 120 % of the range for maximum and 10% of the

range for minimum.

Default

The default is auto-range. The user selected range is stored in volatile

memory and the default will be restored when the meter is power-off.

Please refer to Table 2-1 on page 24 for the factory default range.

How to set the auto / manual range:

You can set the auto / manual range either through the front panel

operation or through the remote interface operation.

Front Panel Operation

First choose a measurement function on the front panel, then press

“AUTO” button to select auto-range feature. Or use △ and ▽ buttons

to manually select a range. If selected range is not shown on the

bottom of the display, press round PREV or NEXT buttons until the range

information appears. The locations of these buttons are shown with a

red rectangle frame in Figure 4-6.

Figure 4-6

Remote Interface Operation

Use the following commands from your PC terminal to set the range:

CONFigure:<function> <range>,<resolution>

MEASure:<function>? <range>,<resolution>

SENSe:<function>:RANGe <range>

SENSe:<function>:RANGe:AUTO {OFF|ON}

4.1.7 Rate (Integration Time)

Definition

Integration time is the period of time the analog-to-digital (A/D)

converter takes to sample the input signal. The integration time feature

allows user to optimize either the speed or the resolution, as well as the

noise rejection and the accuracy of the measurement. The unit of the

integration time is in PLC (power line cycles). One PLC for 60 Hz is 16.67

ms, and for 50 Hz is 20 ms.

There are 4 different integration times in M3500A for user to select from:

0.02, 0.1, 1 and 10 PLCs.

Default

For DCV, DCI, and resistance measurement, the default integration time

is 1 PLC. The user selected value is stored in a volatile memory and the

default value will be restored when the meter is power-off.

How to set the integration time:

You can set the integration time either through the front panel operation

or through the remote interface operation.

Front Panel Operation

Integration time is set indirectly when user selects the measurement

resolution. Please refer to chapter 4.1.3 for details about how to set

resolution or the digits. Table 4-1 on page 51 shows the relationship

between the resolution and the integration time.

Remote Interface Operation

Use the following commands on your PC terminal to set the resolution.

CONFigure:< function> <range>, <resolution>

MEASure:< function>? <range>, <resolution>

SENSe:< function>:RESolution <resolution>

Or you can set integration time directly by the following commands.

SENSe:VOLTage:DC:NPLCycles {0.02|0.1|1|10|MINimum|MAXimum}

SENSe:VOLTage:DC:NPLCycles? [MINimum|MAXimum]

SENSe:CURRent:DC:NPLCycles {0.02|0.1|1|10|MINimum|MAXimum}

SENSe:CURRent:DC:NPLCycles? [MINimum|MAXimum]

SENSe:RESistance:NPLCycles {0.02|0.1|1|10|MINimum|MAXimum}

SENSe:RESistance:NPLCycles? [MINimum|MAXimum]

SENSe:FRESistance:DC:NPLCycles {0.02|0.1|1|10|MINimum|MAXimum}

SENSe:FRESistance:DC:NPLCycles? [MINimum|MAXimum]

For frequency and period measurements, aperture time (or gate time) is

analogous to integration time, and you can use the following commands

to set it. Specify 10 ms (4.5 digits), 100 ms (default; 5.5 digits), or 1

second (6.5 digits).

SENSe:FREQuency:APERture {0.01|0.1|1|MINimum|MAXimum}

SENSe:FREQuency:APERture? [MINimum|MAXimum]

SENSe:PERiod:APERture {0.01|0.1|1|MINimum|MAXimum}

SENSe:PERiod:APERture? [MINimum|MAXimum]

4.1.8 Sensor Selection for Temperature Measurements

The multimeter supports both thermocouple and RTD. User needs to

configure the multimeter for the right sensor type before they can make

temperature measurements.

RTD

(

[

]

(

)

Definition

If you are using RTD, the options are: PT100, D100, F100, PT385,

PT3916, user-defined RTD, NTCT and SPRTD. If you need to change the

factors that are used to calculate the temperature in RTD, choose

user-defined RTD in which you are able to change any factors as you wish.

The default factors used are listed in Table 4-3:

Table 4-3

Type Alpha Beta Delta R-zero

PT100 0.003850 0.10863 1.49990 100Ω

D100 0.003920 0.10630 1.49710 100Ω

F100 0.003900 0.11000 1.49589 100Ω

PT385 0.003850 0.11100 1.50700 100Ω

PT3916 0.003916 0.11600 1.50594 100Ω

NTCT 0.003850 0.10863 1.49990 100Ω

Here is the temperature equation that is used to determine the RTD

temperature:

When

Where:

If you are using SPRTD(Standard Platinum RTD), select SPRTD and

Ct°< 0 :

<° 6300 :

CtC °

++=

⎞ ⎟

100

⎠

410−

⋅−=αδB

810−

⋅−=αβC

1 BtAtRR

⎛

⎜ ⎝

)

1001

−+++= tCtBtAtRR

specify the seven coefficients under SPRTD submenu.

The ITS (International Temperature Scale) -90 standard provides two

reference equations for Standard Platinum Thermometers covering

temperature range from 18.8033K to 1234.93K. However, one SPRTD

usually cannot cover the entire range, so the temperature range is

broken up into a few subranges. These subranges depend on the

calibration point of temperature scale and are based on the melting or

triple points of various pure substances. For an exact list of the elements

needed and details on RTD calibration, refer to NIST Technical Note 1265

“Guidelines For Realizing the International Temperature Scale of 1990”.

In each subrange, the calibration constants required for that subrange

are listed.

Default

The default sensor type in M3500A is PT100.

How to set up RTD

You can set up the RTD configuration either through the front panel

operation or through the remote interface operation.

Front Panel Operation

If you are using RTD, press CONFIG and then TEMP. Use ◁ and ▷ to

locate SENSOR submenu. Press ENTER to go to the submenu. Use ◁

and ▷ to locate your sensor type Press ENTER to select your desired

sensor type.

Choosing USER takes you to a menu where you can specify factors used

in the calculation equation to obtain the temperature. Use ◁ and ▷ to

move through the digits and △ and ▽ to change the numbers to a

desired value. Press ENTER to set the value.

Choosing SPRTD takes you to a menu where you can specify the seven

coefficients that are used to determine the temperature. Use ◁ and ▷

to move through the digits and △ and ▽ to change the numbers to a

desired value. Press ENTER to set the value.

Remote Interface Operation

Use the following commands to set up the RTD configuration.

SENSe:TEMPerature:RTD:TYPE{PT100|D100|F100|PT385|PT3916|USER|SPRTD|NTCT}

SENSe:UNIT {Cel|Far|K}

SENSe:UNIT?

SENSe:TEMPerature:RTD:RZERo {<value>|MINimum|MAXimum} SENSe:TEMPerature:RTD:ALPHa {<value>|MINimum|MAXimum} SENSe:TEMPerature:RTD:BETA {<value>|MINimum|MAXimum} SENSe:TEMPerature:RTD:DELTa {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:RZERo {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:A4 {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:B4 {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:AX {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:BX {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:CX {<value>|MINimum|MAXimum} SENSe:TEMPerature:SPRTD:DX {<value>|MINimum|MAXimum}

Thermocouple

Definition

If users are using the thermocouple function, the selections on the

M3500A are: type E, J, K, N, R, S and T. (On the other hand, other

selection “SIMULATED” simulates the reference junction.) To use the the

thermocouple function, users have to adjust something. First of all, via a

thermocouple adaptor, users need to measure a known and accurate

reference temperature (T1) as a criterion. Then the display of the

M3500A will show a reference value (T2). At the moment, a remainder

(T3) from (T1 – T2) will be calculated. After that, users just adjust the

default (simulated value 23.0°C) to 23.0°C + (T3). Under the

circumstance, the thermocouple function will be activated completely.

For Example:

If the criterion value is (T1 =30.0°C), the reference value showing on the

M3500A is (T2=24.0°C). Users will get a remainder T3 (T1 – T2 = 6.0°C).

Then users just configure the default simulated value from 23.0°C to

29.0°C on the M3500A.

How to set up thermocouple

You can set up the thermocouple configuration either through the front

panel operation or through the remote interface operation.

Front Panel Operation

1. Configure the thermocouple type and unit. Pressing CONFIG > SHIFT

> TEMP (TCOUPL), and then using PREV and NEXT to select the type

and unit.

2. Measure a known and accurate reference temperature (T1). The

result showing on the M3500A is (T2).

3. Adjust the simulated value (23.0°C to 23.0°C + T3.)

4. Configure the Simulated value by pressing CONFIG > SHIFT >

TEMP(TCOUPL) > NEXT > SIMULATED > ENTER, and by buttons 「PREV」 or 「 NEXT」 and △& ▽ assistance to adjust the value.

Remote Interface Operation

Use the following commands to set up the thermocouple configuration.

SENSe:UNIT {Cel|Far|K}

SENSe:UNIT?

SENSe:TCOuple:TYPE {E|J|K|N|R|S|T}

SENSe:TCOuple:SIMulated {<value>|MINimum|MAXimum}

4.1.9 Remote Interface Selection

The multimeter supports both GPIB and USB interfaces, but only one

interface can be activated at a time. If you are using GPIB, you must set

the address for the multimeter. You can set the address to any value

from 0 and 31. The address is set to “11” when the multimeter is shipped

from the factory.

※ Note: The remote interface can only be set through the front panel

operations.

How to select a remote interface

Press MENU and then use ◁ and ▷ to select INTERFACE. Then Press

ENTER on your choice of USB or GPIB interface.

How to set address when using GPIB

Press MENU and then use ◁ and ▷ to access INTERFACE. Select GPIB

to set address. Use ◁, ▷, △and ▽ to adjust the numbers to the

desired address. Press ENTER to set it.

4.1.10 Input Terminal Switch

Definition

User can select either the front input terminals or the rear input

terminals for their measurements. There are 5 input terminals in the

front panel as well as the rear panel. If the rear terminal is enabled the

REAR annunciator at the upper side will be shown.

Default

The default situation is the front terminals.

How to switch the terminals:

To switch between the front and the rear input terminals, press

“TERMINALS” switch button on the front panel. Please see the following

figure for the location of the switch. The location of the button and

terminals is shown with a red rectangle frame in Figure 4-7.

Figure 4-7

4.2 Trigger Operations

In this section we will discuss the triggering system in M3500A. M3500A

provides a variety of trigger operations for user. User can select a trigger

mode, a trigger source and different trigger settings for a specific

measurement. The user’s selection is stored in a volatile memory and the

default settings will be restored after power-off. Figure 4-8 shows the

trigger operation in M3500A.

Figure 4-8

4.2.1 Trigger Mode

There are three trigger modes in M3500A: auto, immediate, and single

triggering. User can specify the trigger mode for their measurement. The

factory default is auto triggering when the meter is power-on.

A. Auto Triggering Mode (Front Panel Operation only)

Definition

Auto triggering takes continuous readings at a fastest rate possible for

the present measurement. The rate of taking readings depends on the

current settings. This function is only available through the front panel.

The auto triggering is also the default for trigger mode in M3500A.

How to use Auto Trigger

Press ATUO TRIGGER on the front panel to toggle for enabling auto

trigger mode. The location of the button is shown with a red rectangle

frame on Figure 4-9.

Figure 4-9

B. Internal Immediate Trigger Mode (Remote Interface Operation Only)

Definition

The immediate triggering mode is only available through the remote

interface operations and it is the default for the remote interface

operations. When the meter is in immediate trigger mode, a trigger will

be issued immediately as soon as the meter is in “wait for event” state.

How to use Immediate Trigger

Use the following command in your PC terminal to set the internal

immediate trigger.

TRIGger:SOURce IMMediate

C. Single Trigger Mode (accessible only through the front panel)

Definition

Single trigger mode takes one reading (or specified number of readings)

each time when user presses SINGLE key. (Please refer to 4.2.3 for

setting the number of samples on each trigger.) When the TRIG

annunciator on the display is lit, the meter is ready for next trigger event.

The single trigger mode is only available through the front panel

operations.

How to use Single Trigger

First select the measurement function, and then press SINGLE key on

the front panel to set the trigger mode. The location of the button is

shown with a red rectangle frame in Figure 4-10.

Figure 4-10

4.2.2 Trigger Source

In M3500A, user can specify the trigger source to be one of these three

options: front panel operations, external hardware trigger source and

remote interface operations.

Front Panel Operation

Use the front panel buttons - AUTO TRIGGER for auto triggering and

SINGLE for single triggering.

External Hardware

User applies a trigger pulse to the Ext TRIG (BNC) terminal on the rear

panel. External hardware triggering is like using single trigger but the

trigger source is an external hardware. When the multimeter receives a

pulse from the trigger source, it takes one reading, or a specified number

of readings. To set the external hardware trigger, press both the SHIFT +

SINGLE buttons to enable external hardware trigger. The lit “EXT”

annunciator on the display indicates the enabling of the external

hardware trigger.

External Triger Terminal

Users can trigger the M3500A by using a low-true pulse to the Ext Trig

(external trigger) terminal located on the rear panel. And to use this

terminal via the remote interface, users have to select the external

trigger source by using the TRIGer:SOURce EXTernal command.

Input

※ Note: Users can use a simple switch to generate an external trigger by

using the Ext Trig input as shown in the following.

> 1 μs

VM COMP (Voltmeter Complete) Terminal

The real panel VM COMP terminal provides a low-true pulse after

finishing each measurement. The VM COMP and external trigger shown

below provides a standard hardware handshake sequence between

measuremen and switching devices.

Output

Approximately

2 μs

Remote Interface Operation (By software or internal trigger)

By software trigger: The software trigger is similar to the single

triggering, but instead of using the “SINGLE” button on the front panel,

you send a command from your PC to the multimeter to generate an

event. For using software trigger, use the following command from your

PC terminal to set trigger source:

TRIGger:SOURce BUS

By internal trigger: The internal trigger is the default trigger mode for

the Remote Interface Operation. In the internal trigger mode, a trigger

signal will be issued whenever the multimeter is in the wait-for-trigger

state. To set the internal trigger, use the following command from your

PC terminal:

TRIGger:SOURce IMMediate

4.2.3 Trigger Setting

In M3500A, user can specify a variety of trigger settings including the

number of samples per trigger, the number of triggers per event, reading

hold, and the trigger delay for their measurements.

A. Number of samples on each trigger

By default, the multimeter takes only one reading on each trigger, but

you can instruct the multimeter to take specific number (up to 50000) of

readings each time it receives a trigger. The user’s input setting is stored

in a volatile memory which will be cleared after the meter has been

turned off and the default value will be restored. You can set the number

of samples on each trigger through front panel or the remote interface.

Front Panel Operation

Press MENU button and locate “TRIG” submenu by pressing ◁ and ▷

buttons. Press ENTER to choose “TRIG” option. Again locate “N SAMPLE”

submenu using ◁ and ▷ buttons and then press ENTER to select it.

Then set the desired number by pressing △and ▽ buttons to increase

or decrease the number, and using ◁ and ▷ buttons to move through

the digits. The locations of these buttons are shown with red rectangle

frames in Figure 4-11.

Procedures: MENU → TRIG → N SAMPLE →<Number>

Figure 4-11

Remote Interface Operation

Use the following command to set the number of samples from your PC

terminal.

SAMPle:COUNt <value>

B. Number of triggers

Although the meter normally takes one trigger before returning to the

“idle” state, user can manually specify the number of triggers it accepts

before the “idle” state. However, this can only be done through the

remote interface. The following command show how to set multiple

triggers per returning idle state.

TRIGger:COUNt <value>

C. Reading hold

The reading hold feature is used to hold a stable reading on the display.

When a reading is stable, enabling the reading hold will hold the stable

reading and trigger a beeping sound. Reading hold feature depends on

an adjustable sensitivity band to determine if a reading is stable. The

multimeter considers a reading stable when three consecutive readings

are within the sensitivity band. Chapter 4.4.6 will explain how to adjust

the sensitivity band.

How to use reading hold

This feature is only available from the front panel operations. To enable

reading hold, press both SHIFT and AUTO TRIGGER buttons. To disable it,

simply press AUTO TRIGGER. The locations of the buttons are shown

with red rectangle frames in Figure 4-12.

Figure 4-12

D. Trigger delay

This feature is useful for user who needs a longer delay time to wait for

the system to be stabilized. The time needed to stabilize a measurement

system is called the “settling time.” The settling time depends on the

measurement range, cable properties and signal source.

Defaults

The default of the trigger delay is automatic. M3500A automatically

selects a delay time for you according to the setting of the measurement

if you do not specify a delay. A list of the default for each measurement

function is shown on Table 4-4. The range for the delay is from 0 to

3600 seconds. User's selection of delay time is stored in a volatile

memory and the default will be restored when the meter is power-off.

The internal settings of automatic trigger delay

The delay time for automatic trigger delay is determined by the selection

of measurement function, range, and the setting of integration time and

AC filter speed. The following table shows the default delay time

for each measurement setting.

Table 4-4

Measurement Function Setting

PLC >= 1 1.5 ms

DCV/DCI

PLC < 1 1.0 ms

100Ω ~ 100kΩ 1.5 ms

Ω2 and Ω4

1 MΩ 15 ms

(PLC >= 1)

10 MΩ ~ 100 MΩ 100 ms

100Ω ~ 100kΩ 1.0 ms

Ω2 and Ω4

1 MΩ 10 ms

(PLC < 1)

10 MΩ ~ 100 MΩ 100 ms

ACV/ACI

3 Hz 7.0 s

(Remote Interface/

20 Hz 1.0 s

External Trigger/

Trigger Delay

Time

Single Trigger)

ACV/ACI

(Front Panel w/ Auto

Trigger On)

200 Hz 600 ms

3 Hz 1.5 s

20 Hz 200 ms

200 Hz 100 ms

Remote Interface /

1.0 s

External

Frequency/Period

Front Panel w/ Auto

0 s

Trigger ON

How to specify a delay time

User can set the delay time from either the front panel operations or the

remote interface operations.

Front Panel Operation

To set the delay time, press MENU button and use ◁ and ▷ buttons to

locate “TRIG” option. Press ENTER to select it. Then again find “DELAY”

option using ◁ and ▷ buttons. Press ENTER to select it. Then use ◁

and ▷ buttons to move through the digits and △ and ▽ buttons to set

the desired delay time (between 0 to 3600 second). The locations of the

buttons are shown with red rectangle frames in Figure 4-13.

Figure 4-13

Remote Interface Operation

You can also use the remote interface operations from your PC terminal

to set the trigger delay. To select a delay time, use the following

command or set the trigger delay to be automatic:

TRIGger:DELay {<seconds>|MINimum|MAXimum}

TRIGger:DELay:AUTO {OFF|ON}

4.3 Math Operations

This section will introduce the mathematical operations in M3500A.

There are eight math operations: RITIO, %, Min/Max, NULL, Limits,

MX+B, dB and dBm testing. They either store data for later use or

perform mathematical operations on the readings. Note that these math

operations are available to all measurement functions except continuity

and diode testing.

※ Note: The “MATH” anunnciator on the display indicates the state of a

mathematical feature, excluding Ratio, and will be lit by enabling

whichever math feature. Also, press the same buttons again for the

enabled math feature will disable the same math feature.

※ Note: Press RATIO button, the “RATIO” anunnciator will be lit on the

display.

4.3.1 Ratio

This function calculates the ratio of an input DC voltage to a reference DC

voltage according to the following equation:

How to make a ratio measurement

There are two ways to make a ratio measurement: Through the front

panel operation or through the remote interface operation.

Front Panel Operation

Use TERMINALS button to select the front terminals or the rear terminals.

Press CONFIG + RATIO, and then use ◁ and ▷ buttons to locate

“RESOLUTION” option (Refer to 4.1.3) and “FILTER” option (Refer to

4.1.2.2). Press ENTER to make choices. Then select desired value for it by pressing ◁, ▷, △ and ▽ button. Press ENTER to choose it. For

operating this function, please press RATIO button and observe the

reading on the display as shown as Figure 4-14.

※ Note: To close this function, please press one of the measurement

function buttons.

Figure 4-14

Remote Interface Operation

Use the following command to make a RATIO measurement.

CONFigure:VOLTage:DC:RATio {<range>|MIN|MAX|DEF},{<resolution>|MIN|MAX|DEF}

4.3.2 % (Percent)

Definition

This mathematical function calculates the ratio of a measurement

reading to a specified target value as the form of percentage. The

calculation formula is shown below:

The specified target value is store in a volatile memory and will be

cleared after the meter has been turned off or a remote interface reset.

How to use % (Percent) function

There are two ways to make a percent measurement: Through the front

panel operation or through the remote interface operation.

Front Panel Operation

To specify a target value, user needs to configure Percent function by

pressing CONFIG + %, then use ◁ and ▷ to move through the digits

and △ and ▽ buttons to increase or decrease the numbers to a desired

target value. Press ENTER to set the value. Press % to activate this

function. And then observe the calculated percent value on the display as

shown as Figure 4-15.

※ Note: Press % again to disable this function. The “MATH” annunciator

on the display indicates the state of a mathematical feature.

Figure 4-15

Remote Interface Operation

Use the following commands to enable and configure Percent function:

CALCulate:FUNCtion PERCent

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:PERCent:TARGet {<value>|MINimum|MAXimum}

CALCulate:PERCent:TARGet? [MINimum|MAXimum]

4.3.3 Min/Max

Definition

When the Min/Max function is enabled, the multimeter takes in a series

of readings from the measurements, stores the minimum and maximum

readings in the memory, and then calculates the average value of all

readings. The number of readings taken since Min/Max operation is

enabled is recorded as well. These data are stored in a volatile memory

and will be cleared when the meter is turned off, or when the MIN/MAX is

turned on, or after a remote interface reset. The meter beeps every time

when it captures a new minimum or maximum.

How to use Min/Max

You can use the Min/Max feature either through the front panel operation

or the remote interface operation.

Front Panel Operation

User first selects the measurement function they wish to use, and then

press MIN/MAX button to enable the Min/Max function. To read the

min/max value, the average value or the readings count, user can press

CONFIG button and then MIN/MAX button. Use ◁ and ▷ buttons to

switch between those values. The locations of the buttons are shown

with red rectangle frames in Figure 4-16.

※ Note: Press MIN/MAX again to disable this feature. The “MATH”

anunnciator on the display indicates the state of a mathematical feature.

Figure 4-16

Remote Interface Operation

The following commands show you how to use the Min/Max operation

from your PC terminal.

CALCulate:FUNCtion AVERage

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:AVERage:MINimum?

CALCulate:AVERage:MAXimum?

CALCulate:AVERage:AVERage?

CALCulate:AVERage:COUNt?

4.3.4 Null

Definition

When null function is enabled, the displayed measurement reading is the

difference between the measured input signal reading and the stored

null (also called relative) value. The null (relative) value is stored in a

volatile memory and the value will be cleared when the multimeter is

power-off. Moreover, user can specify or alter a null value. The null

feature is available for all functions, except continuity, diode. When user

selects the null feature for a measurement, it is visible only for this

measurement.

How to use null (relative) measurement

You can activate null feature from either the front panel operation or the

remote interface operation.

The Front Panel Operation

The null measurements can be used with any function except continuity

and diode. To store the null test lead resistance, short the two test leads

together and then press NULL button. The new reading taken will replace

the old value, if any, in the null register. Then, connect the two test leads

to the input source. The value with null offset will show on the display. In

addition, the null offset value can be adjusted manually by pressing

CONFIG then NULL. Use ◁ and ▷ buttons to move through the digits

and use △ and ▽ buttons to increase or decrease the numbers to a

desired value. Press ENTER to set the value. The locations of the buttons

are shown with red rectangle frames in Figure 4-17.

※ Note: Press NULL again to disable this feature. The “MATH”

anunnciator on the display indicates the state of a mathematical feature.

Figure 4-17

The Remote Interface Operation

You can use the following commands on your PC terminal to make a null

measurement.

CALCulate:FUNCtion NULL

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:NULL:OFFSet {<value>|MAXimum|MINimum}

4.3.5 Limits Test

The limits testing operation allows user to adjust a maximal and a

minimal limit values. The multimeter beeps and an “HI” or “LO” message

will be shown when the reading exceeds the upper or lower limit

respectively. Users can specify the limit values and the values are stored

in a volatile memory. The default values for both upper and lower limits

are “0”. This function is available to all except continuity and diode

measurements.

How to set the limits

You can set the limits or make a limit testing either through the front

panel or the remote interface operation.

Front Panel Operation

To set the limits, user needs to configure the LIMITS math function by

pressing CONFIG + SHIFT + RATIO, and then use ◁ and ▷ to locate

either lower limit (MIN) or upper limit (MAX). Press ENTER to select the

limit you wish to set. Then use ◁ and ▷ to move through the digits and

△ and ▽ to increase or decrease the numbers to a desired value. Press

ENTER to set the value. The locations of the buttons are shown with red

rectangle frames in Figure 4-18.

Figure 4-18

How to make a limit testing

The locations of the buttons are shown with red rectangle frames in

Figure 4-19.

z Select a measurement function for purpose except continuity and

diode.

z Enable the limit operation by pressing SHIFT + RATIO buttons. z After enabling the limit function, user can set the limit value as

mentioned above.

z Observe the displayed reading.

※ Note: Press SHIFT+RATIO again to disable this feature. The “MATH”

anunnciator on the display indicates the state of a mathematical feature.

Figure 4-19

Remote Interface Operation

Use the following commands to enable the limits function or to set the

limits:

CALCulate:FUNCtion LIMit

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:LIMit:LOWer {<value>|MINimum|MAXimum} CALCulate:LIMit:UPPer {<value>|MINimum|MAXimum}

4.3.6 MX+B

Definition

This mathematical function multiplies a measurement reading (X) by a

specified scale factor (M) and add an offset (B) automatically. The

answer (Y) will then be shown on the display according to the following

equation.

Y=MX+B

This is especially useful when user needs to do slope calculations on a

series of measurements.

The values of the “M” and “B” can be changed through the configuration

of this function and they are stored in a volatile memory and will be

cleared after the meter has been turned off or a remote interface reset.

User can either use front panel or remote interface to perform this

function and set these two constant.

How to use MX+B function

You can use MX+B function from the front panel operation or the remote

interface operation.

Front Panel Operation

To set the values of M and B, user needs to configure this math function

by pressing CONFIG and SHIFT + %. Use ◁ and ▷ to switch between M

and B. Press ENTER on your selection. Then use ◁ and ▷ to move

through the digits and use △ and ▽ to increase or decrease the number

to a desired value. Press ENTER to set the value. User needs to set the

values of M and B first. Then Select a measurement function and press

SHIFT + % to activate MX+B function as shown as Figure 4-20.

Figure 4-20

Remote Interface Operation

Use the following commands to enable and configure MX+B function:

CALCulate:FUNCtion MXB

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:MXB:MMFactor {<value>|MINimum|MAXimum}

CALCulate:MXB:MMFactor? [MINimum|MAXimum]

CALCulate:MXB:MBFactor {<value>|MINimum|MAXimum}

CALCulate:MXB:MBFactor? [MINimum|MAXimum]

4.3.7 dB/dBm

A. dB

Definition

The dB feature takes a DC or AC voltage measurement and displays it in

decibel unit in correspondence to a relative reference value. The

calculation of dB is listed below:

dB = (Input signal in dBm) – (relative value in dBm)

×=

Vref

)log(20

※ NOTE: The

The dB measurement is applied to DC and AC voltage only. The relative

value is adjustable and is stored in a volatile memory. The range for the

relative value is between 0 dBm and

How to set the relative value

User can either manually select a number for the relative reference or let

the multimeter take the first reading (0 dB).

Front Panel Operation

Press CONFIG+ SHIFT+ NULL buttons, and then use ◁ and ▷ to move

through the digits and △ and ▽ buttons to increase or decrease the

numbers to your desired value. Press ENTER to set the value. The

locations of the buttons are shown with red rectangle frames in Figure

4-21.

V is the input signal and the

200 dBm.

V is the relative reference.

ref

Figure 4-21

How to make a dB measurement

z Select the measurement function by pressing one of DCV and ACV

buttons.

z Enable the dB operation by pressing SHIFT + NULL buttons. z After enabling the dB operation, user can set or alter the dB relative

value as mentioned above.

z Observe the displayed reading.

Figure 4-22 shows the locations of these buttons with red rectangle frames.

※ Note: Press SHIFT+NULL again to disable this feature. The “MATH”

anunnciator on the display indicates the state of a mathematical feature.

Figure 4-22

Remote Interface Operation

Use the following commands from your PC terminal to make the dB

measurement:

CALCulate:FUNCtion DB

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:DB:REFerence {<value>|MINimum|MAXimum}

B. dBm

Definition

With dBm selected, a voltage measurement is displayed as the level of

power, relative to 1 milliwatt, dissipated through a reference resistance.

The reference resistance is adjustable in M3500A. The calculation of dBm

is defined as below:

⎛

×=

⎜ ⎝

⎞

1/log10

⎟

ref

⎠

※ Note:

※ Note: Change of reference resistance will not affect the stored relative

reference value.

z The Zref is adjustable with a range from 50Ω to 8000 Ω. The default

value is 600 Ω.

z The user selected reference value is stored in a volatile memory and

will be cleared after the multimeter has been power-off.

z This feature is available for DCV and ACV only.

How to set the reference resistance

User can set the reference resistance either through the front panel

operation or the remote interface operation.

Front Panel Operation

Press CONFIG + SHIFT + MIN/MAX, then use ◁ and ▷ to move

V is the input signal voltage.

Z is the reference resistance.

ref

through the digits and △ and ▽ to increase or decrease the numbers to

a desired value. Press ENTER to set the value. The locations of the

buttons are shown with red rectangle frames in Figure 4-23.

Figure 4-23

How to make a dBm measurement

z Select a measurement function by pressing DCV or ACV button. The

dBm feature is only available for DCV and ACV only.

z To enable dBm, press SHIFT + MIN/MAX buttons. z After enabling the dBm operation, user can select the reference

resistance as mentioned above. The default for the reference

resistance is 600 Ω.

The locations of the buttons are shown with red rectangle frames in

Figure 4-24.

※ Note: Press SHIFT+MIN/MAX again to disable this feature. The

“MATH” anunnciator on the display indicates the state of a mathematical

feature.

Figure 4-24

Remote Interface Operation

Use the following commands to enable dBm feature or to set the

reference resistance:

CALCulate:FUNCtion DBM

CALCulate:STATe {OFF|ON}

CALCulate:STATe?

CALCulate:DBM:REFerence {<value>|MINimum|MAXimum}

4.4 Other System Related Operations

Each system related operation performs a task that is not measurement

related but plays an important role in making your measurements.

4.4.1 Display

M3500A has a 5x7 dot matrix, dual-display with three-color (White, Red

and Yellow) annunciators for a better view. A maximum 13 characters

are allowed for upper row dot-matrix display and a maximum 16

characters are allowed for lower row dot-matrix display as shown on

Figure 4-25.

measurement without waiting for display, or when the measurement is

done through the remote interface operations on their PC terminal.

When the display is turned off, an “OFF” will be lit at the lower right

corner of the display screen. This doesn't mean the display is

POWER-OFF, but only that the measurement readings will not be sent to

the display. This option will accelerate the measurement process

because there is no I/O delay. But turning off the display will not affect

the messages displayed from the RECALL, MENU and CONFIG

operations.

User has an option to turn off the display for a faster

Figure 4-25

User can send a message through the remote interface from their PC

terminal to the lower row display and will substitute the original display.

Default

The display default is “ON”. The “On/Off” selection made by user is

stored in a volatile memory and the default “ON” will be restored when

the meter is power-off.

How to control the display

You can control the display through the front panel operation or through

the remote interface operation. The remote interface operation has

higher priority over the front panel operation.

Front Panel Operation

Use the following steps to control the display: Press MENU button then

use ◁ and ▷ buttons to locate “SYSTEM” submenu. Press ENTER to

select it, and then again use ◁ and ▷ buttons to locate “DISPLAY”

submenu. Press ENTER to select it, and then find ON or OFF by using ◁

and ▷ buttons. Press ENTER on your selection. The locations of the

buttons are shown with red rectangle frames in Figure 4-26.

Procedures: MENU → SYSTEM → DISPLAY → {ON|OFF}

Figure 4-26

Remote Interface Operation

The following commands show how to control the display as well as how

to send a message to the display:

DISPlay {OFF|ON} (turns off or turns on the display) DISPlay:TEXT <quoted string> (displays the string you type in)

DISPlay:TEXT:CLEar (clears the message displayed)

4.4.2 Beeper

M3500A multimeter beeps when some certain conditions are met or

when an error occurs. But there may be time you want to disable the

beeper for some operations. Although you can turn off the beeper, the

click sound you hear when a button is pressed will not be disabled. The

beeper state is stored in a volatile memory and the default will be

restored when the meter has been turned off or after a remote interface

reset.

By disabling the beeper you will not hear the meter beeps when:

z a new minimum or maximum is found in Min/Max operation. z a stable reading is detected and held. z the test voltage is within the limits in diode testing. z the source signal fails the limit testing.

After the beeper is disabled, the meter still emits a tone when:

z an error occurs. z any button on the front panel is pressed. z the threshold value is exceeded in continuity testing.

Default

The beeper is enabled when it is shipped from the factory.

How to control the beeper

User can control the beeper from either the front panel operation or the

remote interface operation.

Front Panel Operation

Follow the procedure below to disable or enable the beeper: Press MENU

button then use ◁ and ▷ buttons to find SYSTEM menu. Press ENTER

to choose it, and then again use ◁ and ▷ buttons to find BEEP menu.

Press ENTER to choose it, and then find ON or OFF by using ◁ and ▷

buttons. Press ENTER on your selection. The locations of the buttons are

shown with red rectangle frames in Figure 4-27.

Procedures: MENU → SYSTEM → BEEP→ {ON|OFF}

Figure 4-27

Remote Interface Operation

The following commands show how to use the remote interface operation

to disable or enable the beeper:

SYSTem:BEEPer

SYSTem:BEEPer:STATe {OFF|ON}

4.4.3 Reading Memory (Store & Recall)

M3500A has a memory capacity of 2000 readings. The readings are

stored in first-in-first-out order and the memory type is volatile, which

means the stored readings will be cleared when the multimeter is

power-off. The reading memory feature can be used for all measurement

functions, math operations, trigger operations and reading hold.

How to use the reading memory

User can store the readings and access to the stored readings through

either the front panel operation or the remote interface operation.

※ Note: Each datum stored from M3500A to remote interface will be in

a first in and first out condition.

Front Panel Operation

Before using the reading memory feature, user needs to select a

measurement function (or the math function) first and then select the

trigger mode.

To store readings, use the following steps:

Press STORE button, and the multimeter will start to store the readings

produced until the specified number of readings is reached. The default

number of readings to store is 100. To change this number, press

CONFIG and then STORE buttons. Then use ◁ and ▷ buttons to move

between the digits and ▽ and △ buttons to increase or decrease

numbers as desired. When ready, press ENTER button. The default

number of readings will be restored when the meter has been turned off.

The location of the buttons are shown with red rectangle frames in

Figure 4-28.

※ Note: The MEM annunciator will be lit while the multimeter stores

readings and be turned off when the specified number of readings is

reached.

Procedures: CONFIG +STORE→ <NUMBER>

Figure 4-28

To recall the stored readings, use the following steps:

Press RECALL button, and the multimeter will display all the stored readings starting from the first reading. Use ◁ and ▷ or ▽and △

buttons to move from the first reading to the last reading the meter has

stored. The locations of the buttons are shown with red rectangle frames

in Figure 4-29.

Figure 4-29

Remote Interface Operation

Users can use the following commands from their PC terminals to store or retrieve readings in the memory. In addition, the number for STORE

function only can be set through front panel.

INITiate (This command tells the meter to be on “wait-for-trigger” state.

After a measurement is taken, measurement readings will be placed in the memory.)

FETCh? (Use this command to retrieve stored readings.)

DATA:POINts? (Use this command to query the number of stored

readings.)

4.4.4 Sensitivity Band (Hold)

The reading hold function captures and holds a stable reading on the

display. The multimeter beeps and holds the value when it detects a

stable reading. The sensitivity band in reading hold decides which

reading is stable enough. This band is expressed as a percent of reading

on the selected range. The multimeter considers a reading stable when

three consecutive values are within the band. User has an option to

adjust this sensitivity band.

Default

The default band is 0.1%. User’s selection is stored in a volatile memory

and it will be cleared after the meter has been turned off.

How to adjust the sensitivity band

You can adjust the sensitivity band through either the front panel

operation or the remote interface operation.

Front Panel Operation

In order to adjust the sensitivity band, please press MENU button then

use ◁ and ▷ buttons to find “TRIG” submenu. Press ENTER to select it.

Then again use ◁ and ▷ buttons to find “READ HOLD” submenu. Press

ENTER to choose it. Then use ◁ and ▷ buttons to choose a desired

band. Press ENTER to set the desired sensitivity band. The locations of

the buttons are shown with red rectangle frames in Figure 4-30.

Figure 4-30

4.4.5 Scanning (Scan)

User can purchase an optional internal scanner card to be used with

M3500A as the following picture shown. This multipoint scanner card lets

you switch and scan up to 10 channels of input signals. User can open

and close individual channels, set scan count and scan interval, store

measurement readings and activate measuring through channels

defined with different measurement functions. The measurements are

taken through all defined channels in sequence. The scan count limits the

total number of measurements the multimeter makes through all

defined channels in one single scanning operation. The scan interval is

the period of time the multimeter waits before it makes a measurement

through the first defined channel. The configuration made by user is

stored in a volatile memory and will be cleared after the meter is turned

off.

※ Note: The output 2 is only for 4-wired resistance measurement.

Please refer to the above picture for more connection information. When

you use 4-wired resistance measurement with scanner card, please note

that the channel 1 is relative to the channel 6, channel 2 to channel 7 and

so on.

※ Note: Setting range of scanner card is only limited on DCV, DCI, ACV,

ACI, Frequency, Period and Resistance functions. As to the current

measurements, users can install current shunts on the circuit board R1

and R2 to allow indirect AC and DC current measurements to be made

through channels 1 and 6 only.

Remark 1: In the default situation, current shunts are not installed in

the scanner card.

Remark 2: When the current shunts are installed the channel 1 and

channel 6 will be limited to the current measurement unless users

release the shunts of the R1 and R2.)

※ Note: The Information regarding the Limitation of Input Signals in Scanner Card is in the following statement.

10 Channels: 10 channels of 2-pole relay input. All channels configurable to 4-pole. CAPABILITIES: Multiplex one of ten 2-pole or one of five 4-pole signals into DMM.

INPUTS Maximum Signal Level: DC Signals: 110V DC, 1A switched, 30VA maximum (resistive load). AC Signals: 125V AC rms or 175V AC peak, 100kHz maximum, 1A switched,

62.5VA maximum (resistive load). Contact Life: >100000 operations at maximum signal level; >100000000 operations cold switching. Contact Resistance: <1ohm at end of contact life. Actuation Time: 5ms maximum on/off. Contact Potential: <±500nV typical per contact, 1μV max. <±500nV typical per contact pair, 1μV max. Connector Type: Screw terminal, #22 AWG wire size. Isolation Between Any Two Terminals: >10 Gohm, <75pF. Isolation Between Any Terminal and Earth: >10 Gohm, <150pF. Common Mode Voltage: 350V peak between any terminal and earth. Maximum Voltage Between Any Two Terminals: 200V peak. Maximum Voltage Between Any Terminal and M3500A Input LO: 200V peak.

ENVIRONMENTAL: Meets all M3500A environmental specifications.

M3500A-opt01 Scanner Card Configuration & Speed List:

Picotest Corp M3500A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual