Fluke 2638A Operating Manual

2638A

HYDRA Series III Data Acquisition Unit

Users Manual

June 2013

© 2013 Fluke Corporation. All rights reserved. Specifications are subject to change without notice.
All product names are trademarks of their respective companies.

LIMITED WARRANTY AND LIMITATION OF LIABILITY

Each Fluke product is warranted to be free from defects in material and workmanship under normal use and
service. The warranty period is one year and begins on the date of shipment. Parts, product repairs, and
services are warranted for 90 days. This warranty extends only to the original buyer or end-user customer of
a Fluke authorized reseller, and does not apply to fuses, disposable batteries, or to any product which, in
Fluke's opinion, has been misused, altered, neglected, contaminated, or damaged by accident or abnormal
conditions of operation or handling. Fluke warrants that software will operate substantially in accordance
with its functional specifications for 90 days and that it has been properly recorded on non-defective media.
Fluke does not warrant that software will be error free or operate without interruption.

Fluke authorized resellers shall extend this warranty on new and unused products to end-user customers
only but have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is
available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the
applicable international price. Fluke reserves the right to invoice Buyer for importation costs of
repair/replacement parts when product purchased in one country is submitted for repair in another country.

Fluke's warranty obligation is limited, at Fluke's option, to refund of the purchase price, free of charge repair,
or replacement of a defective product which is returned to a Fluke authorized service center within the
warranty period.

To obtain warranty service, contact your nearest Fluke authorized service center to obtain return
authorization information, then send the product to that service center, with a description of the difficulty,
postage and insurance prepaid (FOB Destination). Fluke assumes no risk for damage in transit. Following
warranty repair, the product will be returned to Buyer, transportation prepaid (FOB Destination). If Fluke
determines that failure was caused by neglect, misuse, contamination, alteration, accident, or abnormal
condition of operation or handling, including overvoltage failures caused by use outside the product’s
specified rating, or normal wear and tear of mechanical components, Fluke will provide an estimate of repair
costs and obtain authorization before commencing the work. Following repair, the product will be returned to
the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges
(FOB Shipping Point).

THIS WARRANTY IS BUYER'S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE
FOR ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES OR LOSSES,
INCLUDING LOSS OF DATA, ARISING FROM ANY CAUSE OR THEORY.

Since some countries or states do not allow limitation of the term of an implied warranty, or exclusion or
limitation of incidental or consequential damages, the limitations and exclusions of this warranty may not
apply to every buyer. If any provision of this Warranty is held invalid or unenforceable by a court or other
decision-maker of competent jurisdiction, such holding will not affect the validity or enforceability of any other
provision.

Fluke Corporation
P.O. Box 9090
Everett, WA 98206-9090
U.S.A.

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

11/99

To register your product online, visit register.fluke.com

Table of Contents

Chapter Title Page

1 Product Overview and Specifications ............................................... 1-1

Introduction ........................................................................................................ 1-3

Product Overview .............................................................................................. 1-3

Front and Rear-Panel Overview ......................................................................... 1-4

Safety Information ............................................................................................. 1-8

Screen Capture Feature ...................................................................................... 1-10

About this Manual ............................................................................................. 1-11

The Product Manual Set .................................................................................... 1-11

How to Contact Fluke ........................................................................................ 1-12

Calibration and Repair Information ................................................................... 1-12

General Specifications ....................................................................................... 1-12

Measurement Specifications .............................................................................. 1-14

DC Voltage .................................................................................................... 1-14

DC Voltage Input Characteristics ............................................................. 1-14

DC Voltage Accuracy ............................................................................... 1-15

DC Voltage Additional Errors .................................................................. 1-15

AC Voltage .................................................................................................... 1-15

AC Voltage Input Characteristics ............................................................. 1-15

AC Voltage Accuracy .................................................................................... 1-16

Additional Low Frequency Errors ................................................................. 1-16

DC Current .................................................................................................... 1-16

DC Current Input Characteristics .............................................................. 1-16

DC Current Accuracy ................................................................................ 1-17

DC Current Additional Errors ................................................................... 1-17

AC Current .................................................................................................... 1-17

AC Current Input Characteristics .............................................................. 1-17

AC Current Accuracy ................................................................................ 1-18

Additional Low Frequency Errors ................................................................. 1-18

Frequency ...................................................................................................... 1-18

Frequency Accuracy .................................................................................. 1-18

Resistance ...................................................................................................... 1-18

Resistance Input Characteristics ............................................................... 1-19

Resistance Accuracy ................................................................................. 1-19

Resistance Additional Errors ..................................................................... 1-19

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RTD ............................................................................................................... 1-20

RTD Temperature Accuracy ..................................................................... 1-20

RTD Measurement Characteristics ........................................................... 1-20

Thermistor ..................................................................................................... 1-20

Thermistor Temperature Accuracy ........................................................... 1-20

Thermistor Measurement Characteristics .................................................. 1-21

Thermocouple ................................................................................................ 1-21

Thermocouple Temperature Accuracy ...................................................... 1-21

Thermocouple Measurement Characteristics ............................................ 1-23

Digital I/O ...................................................................................................... 1-23

Totalizer ......................................................................................................... 1-23

Trigger ........................................................................................................... 1-23

Alarm Output ................................................................................................. 1-23

2638A-100 Universal Input Module .................................................................. 1-23

General .......................................................................................................... 1-23

2 Initial Setup and Configuration .......................................................... 2-1

Introduction ........................................................................................................ 2-3

Set the Regional Voltage ................................................................................... 2-3

Connect to Mains Power .................................................................................... 2-4

Set the Handle Position ...................................................................................... 2-5

Power On and Standby ...................................................................................... 2-6

Warm-Up the Product ........................................................................................ 2-7

Configure the Product ........................................................................................ 2-7

Input Module and Relay Card Installation ......................................................... 2-8

Set Up Security .................................................................................................. 2-11

3 Input and Channel Configuration ....................................................... 3-1

Introduction ........................................................................................................ 3-3

Input Wiring ....................................................................................................... 3-3

The Universal Input Module.......................................................................... 3-3

Wiring Safety and Considerations ................................................................. 3-4

3-Wire and 4-Wire Sense Input Configuration .............................................. 3-5

Input Types and Wiring Diagrams ................................................................ 3-6

Input Wiring Instructions .............................................................................. 3-7

Channel Configuration ....................................................................................... 3-9

About Channel Numbers ............................................................................... 3-9

Basic Channel Operations ............................................................................. 3-11

Open the Channel Setup Menu ................................................................. 3-11

Set Channels to ON or OFF ...................................................................... 3-12

Verify a Channel ....................................................................................... 3-13

Zero a Channel .......................................................................................... 3-13

Copy a Channel ......................................................................................... 3-14

Save or Load a Channel Configuration (Setup File) ................................. 3-15

Reset the Channel and Test Configuration ................................................ 3-17

Analog Channel Configuration (Ch001, Ch101 to Ch322) ........................... 3-17

Current and Voltage Channels .................................................................. 3-18

Resistance Channels .................................................................................. 3-19

Thermocouple Channels ............................................................................ 3-20

Frequency Channels .................................................................................. 3-21

Thermistor Channels ................................................................................. 3-22

3-23

PRT Channels............................................................................................

Digital I/O (DIO) Channel Configuration (Ch401) ....................................... 3-24

Totalizer Channel Configuration (Ch402) ..................................................... 3-25

ii

Contents (continued)

Read Mode ................................................................................................ 3-25

Debounce .................................................................................................. 3-25

Math Channel Configuration (Ch501 to Ch520) ........................................... 3-27

Mx+B, Alarms, and Channel Options ................................................................ 3-30

Mx+B Scaling ................................................................................................ 3-30

HI and LO Channel Alarms ........................................................................... 3-31

Channel Delay ............................................................................................... 3-33

Rate of Change .............................................................................................. 3-33

NPLC ............................................................................................................. 3-34

Input Impedance ............................................................................................ 3-34

Bandwidth ..................................................................................................... 3-34

Display As ..................................................................................................... 3-34

Open Detect ................................................................................................... 3-34

4 Scan/Monitor, Record, and Data ........................................................ 4-1

Introduction ........................................................................................................ 4-3

Scan .................................................................................................................... 4-3

About Scan Timing and Sampling ................................................................. 4-5

Configure a Scan ........................................................................................... 4-7

Trigger Type.............................................................................................. 4-8

Auto Recording ......................................................................................... 4-9

File Destination ......................................................................................... 4-9

Sample Rate .............................................................................................. 4-9

Data Security ............................................................................................. 4-10

Temperature Unit ...................................................................................... 4-11

Align Channels .......................................................................................... 4-11

Automatic Power Loss Scan Resume ........................................................ 4-12

Basic Scan Procedures ................................................................................... 4-12

Start a Scan ................................................................................................ 4-12

View Scan Data and Statistics ................................................................... 4-13

Graph the Measurements ........................................................................... 4-14

Monitor .............................................................................................................. 4-15

Record ................................................................................................................ 4-16

Record Measurement Data ............................................................................ 4-16

Memory Consumption for Recorded Data .................................................... 4-17

Open and View Measurement Data on a PC ................................................. 4-17

How to Read the Setup CSV File .................................................................. 4-19

How to Read the Data CSV File .................................................................... 4-21

5 DMM Operation .................................................................................... 5-1

Introduction ........................................................................................................ 5-3

About the DMM Function ................................................................................. 5-3

Input Type Selection and Range Adjustment .................................................... 5-3

More Functions (PT385 or PT392) .................................................................... 5-4

Relative Measurements ...................................................................................... 5-4

Graph the Measurements ................................................................................... 5-5

Measurement Statistics ...................................................................................... 5-6

6 Maintenance and Care ........................................................................ 6-1

Introduction ........................................................................................................ 6-3

Clean the Product ............................................................................................... 6-3

Replace the Fuse ................................................................................................ 6-3

Memory Reset and Factory Reset ...................................................................... 6-4

User-Replaceable Parts and Accessories ........................................................... 6-5

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7 Error Messages and Troubleshooting ............................................... 7-1

Introduction ........................................................................................................ 7-3

Error Messages .................................................................................................. 7-3

Troubleshooting ................................................................................................. 7-19

iv

List of Tables

Table Title Page

1-1. Front-Panel Features .............................................................................................. 1-4

1-2. Rear-Panel Features ............................................................................................... 1-6

1-3. Symbols .................................................................................................................. 1-8

2-1. Fuses ....................................................................................................................... 2-3

2-2. Instrument Setup Menu .......................................................................................... 2-7

3-1. Types of Inputs ....................................................................................................... 3-7

3-2. Channel Types and Numbers ................................................................................. 3-9

3-3. Channel Setup Menu .............................................................................................. 3-11

3-4. Current and Voltage Channel Configuration .......................................................... 3-18

3-5. Resistance Channel Configuration ......................................................................... 3-19

3-6. Thermocouple Channel Configuration ................................................................... 3-20

3-7. Frequency Channel Configuration ......................................................................... 3-21

3-8. Thermistor Channel Setup ...................................................................................... 3-22

3-9. PRT Channel Setup ................................................................................................ 3-23

3-10. Totalizer Channel Configuration ............................................................................ 3-26

3-11. Math Channel Formulas ......................................................................................... 3-27

3-12. Math Channel Configuration .................................................................................. 3-29

4-1. The Scan Menu ...................................................................................................... 4-4

4-2. Settling Time Delay Values ................................................................................... 4-6

4-3. Scan Sample Rates ................................................................................................. 4-10

4-4. Scan Statistics ......................................................................................................... 4-14

4-5. Scan Data Memory Usage ...................................................................................... 4-17

5-1. Statistics ................................................................................................................. 5-6

6-1. Fuses ....................................................................................................................... 6-3

6-2. Comparison of the Memory Clear Functions ......................................................... 6-4

6-3. User-Replaceable Parts and Accessories ................................................................ 6-5

7-1. Error Messages ....................................................................................................... 7-3

7-2. Troublehooting Chart ............................................................................................. 7-19

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vi

List of Figures

Figure Title Page

1-1. Screen Capture ....................................................................................................... 1-10

2-1. Fuse Replacement and Line-Voltage Selection...................................................... 2-3

2-2. Mains Power Cord Connection .............................................................................. 2-4

2-3. Handle Positions and Boot Removal ...................................................................... 2-5

2-4. Main Power Switch and Standby Key .................................................................... 2-6

2-5. Module Indicator Example ..................................................................................... 2-9

2-6. Relay Card Installation ........................................................................................... 2-10

3-1. 2-Wire, 3-Wire, and 4-Wire Example Connections ............................................... 3-3

3-2. 3-Wire and 4-Wire Channel Reservation ............................................................... 3-6

3-3. Module Indicator (Input Module Installed Shown) ................................................ 3-8

3-4. Example Channel Assignment ............................................................................... 3-10

3-5. Channel Status Indicators ....................................................................................... 3-12

3-6. Zero Function ......................................................................................................... 3-14

3-7. DIO Connector ....................................................................................................... 3-24

3-8. Totalizer Input (TOT) ............................................................................................ 3-25

3-9. Rear-Panel Alarm Outputs ..................................................................................... 3-32

3-10. Alarm Output Example .......................................................................................... 3-32

4-1. Scan Data ............................................................................................................... 4-4

4-2. Illustration of a Scan Sweep ................................................................................... 4-6

4-3. Test Setup Menu Example ..................................................................................... 4-8

4-4. Scan Data ............................................................................................................... 4-13

4-5. Graph Feature ......................................................................................................... 4-14

4-6. Monitor Menu ........................................................................................................ 4-15

4-7. Scan Data File Name Convention .......................................................................... 4-18

4-8. Setup.csv and Dat00001.csv Files .......................................................................... 4-19

5-1. Example Voltage Front-Panel Connection ............................................................. 5-3

5-2. Input Function Selection ........................................................................................ 5-4

5-3. Relative Measurement ............................................................................................ 5-5

5-4. Graph Function ....................................................................................................... 5-5

5-5. DMM Statistics ...................................................................................................... 5-6

6-1. Fuse Replacement .................................................................................................. 6-4

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viii

Chapter 1

Product Overview and Specifications

Title Page

Introduction ........................................................................................................ 1-3

Product Overview .............................................................................................. 1-3

Front and Rear-Panel Overview ......................................................................... 1-4

Safety Information ............................................................................................. 1-8

Screen Capture Feature ...................................................................................... 1-10

About this Manual ............................................................................................. 1-11

The Product Manual Set .................................................................................... 1-11

How to Contact Fluke ........................................................................................ 1-12

Calibration and Repair Information ................................................................... 1-12

General Specifications ....................................................................................... 1-12

Measurement Specifications .............................................................................. 1-14

DC Voltage .................................................................................................... 1-14

DC Voltage Input Characteristics ............................................................. 1-14

DC Voltage Accuracy ............................................................................... 1-15

DC Voltage Additional Errors .................................................................. 1-15

AC Voltage .................................................................................................... 1-15

AC Voltage Input Characteristics ............................................................. 1-16

AC Voltage Accuracy .................................................................................... 1-16

Additional Low Frequency Errors ................................................................. 1-16

DC Current .................................................................................................... 1-17

DC Current Input Characteristics .............................................................. 1-17

DC Current Accuracy ................................................................................ 1-17

DC Current Additional Errors ................................................................... 1-17

AC Current .................................................................................................... 1-17

AC Current Input Characteristics .............................................................. 1-18

AC Current Accuracy ................................................................................ 1-18

Additional Low Frequency Errors ................................................................. 1-18

Frequency ...................................................................................................... 1-18

Frequency Accuracy .................................................................................. 1-18

Resistance ...................................................................................................... 1-19

Resistance Input Characteristics ............................................................... 1-19

Resistance Accuracy ................................................................................. 1-19

Resistance Additional Errors ..................................................................... 1-19

RTD ............................................................................................................... 1-20

RTD Temperature Accuracy ..................................................................... 1-20

RTD Measurement Characteristics ........................................................... 1-20

Thermistor ..................................................................................................... 1-20

Thermistor Temperature Accuracy ........................................................... 1-21

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Thermistor Measurement Characteristics .................................................. 1-21

Thermocouple ................................................................................................ 1-21

Thermocouple Temperature Accuracy ...................................................... 1-21

Thermocouple Measurement Characteristics ............................................ 1-23

Digital I/O ...................................................................................................... 1-23

Totalizer ......................................................................................................... 1-23

Trigger ........................................................................................................... 1-23

Alarm Output ................................................................................................. 1-23

2638A-100 Universal Input Module .................................................................. 1-23

General .......................................................................................................... 1-23

1-2

Product Overview and Specifications

Introduction 1

Introduction

This chapter supplies information about the Product, the manual set, safety information,
contact information, and specifications.

Product Overview

The Fluke Calibration 2638A HYDRA Series III Data Acquisition Unit (the Product or
Instrument) is a 67 analog channel bench-top data logger that measures and records dc
volts, ac volts, dc current, ac current, resistance, frequency, and temperature (see
Table 1-1). See the Specifications section for information on the types and ranges of the
measurement inputs the Product can accept.

Features of the Product include:

•

Scan – Sequentially scan up to 67 analog channels per scan sweep. In addition, the

Product also has 20 math channels, one DIO channel, and one TOT channel that can
be included in scan. A scan can be manually controlled from the front panel or
triggered with a variety of triggers such a timer, an alarm, an external source, or a
remote SCPI command.
While a scan is in progress, all channel values can be viewed on the display in a
spreadsheet format along with statistics such as average, standard deviation,
minimum, maximum, peak-to-peak, and rate-of-change. With the Graph feature,
channel measurement data for up to four channels can be plotted and viewed on the
display. Users can toggle the data mode with a softkey to view live data or historical
data.

•

Monitor – View the measurement value or the statistics of a single channel. Monitor

is an independent feature that can be used while a scan is in progress or inactive.
Much like the Scan feature, the statistics of the single measurement can be viewed on
the display or be shown in a graph.

•

Data Storage - Store up to 160 Mb of data and channel setup files directly to the

internal non-volatile memory or an external USB drive. Data can also be transferred
to a PC with a USB drive or LAN TCP/IP interface at the rear of the unit with SCPI
interface command sets.

•

Alarms – Each channel can be assigned two independent alarms to indicate when

either an upper (HI) or lower (LO) range has been exceeded. The alarms can be
configured to output a digital signal from the rear-panel alarm output for control of
external devices.

•

Digital I/O (DIO) – The Product is equipped with a digital 8-bit transistor-transistor

logic (TTL) port that can sense and output. When the DIO channel is included in the
scan list, the value of this port is recorded in the scan data record on each scan with a
value range of 0 to 255 based on the port state when it is read.

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• Totalizer – The Product is equipped with a unidirectional, resettable totalizer with an

input count capability of 1,048,575 (20 bits). Counter increment is accomplished
through a change to a digital signal or contact closure to the totalizer input terminals
on the rear of the Instrument.

•

Digital Multimeter Functionality (DMM) – Function that presents the user with

familiar DMM features and controls like a standard bench DMM. The DMM can
show 6 ½ digits on the display. To visualize trend data, the DMM provides additional
functionality to graph and see measurement statistics.

•

Remote Operation – Remotely operate the Product with remote SCPI commands or

the FlukeDAQ application software over a rear-panel USB or LAN TCP/IP
connection.

Front and Rear-Panel Overview

Table 1-1 identifies and describes the front-panel features and Table 1-2 identifies and
describes the rear-panel features.

Table 1-1. Front-Panel Features

9

8

7

6

Item Name Function

10

11

X

12

345 2

13

14

15

16

17

18

19

20

1

hce001.eps

1-4



Standby Key

Puts the Product in the standby mode. In standby, the display is off and
the keys are disabled. Standby mode also disables remote operation.
See “Power ON and Standby” in Chapter 2.

Product Overview and Specifications

Front and Rear-Panel Overview 1

Table 1-1. Front-Panel Features (cont.)

Item Name Function

Function softkeys to open submenus and set selections. The function of

Function Softkeys



Arrow Keys



USB Data Transfer



Indicator

the softkey changes with each menu and is shown above the softkey
on the display.

Scroll menus, increase or decrease values, and highlight selections.
The keys also let the user cycle through measurement values in data
menus and also change the view of graphs.

Red LED that illuminates when the USB drive is recognized and flashes
red when data is transferred to or from the USB drive.

Caution

To prevent data loss, do not remove the USB drive when

Front-Panel USB Port



Current Input Terminal



the LED is flashing.

USB port to insert a USB drive.

Input terminal to make current measurements up to 100 mA. The
current input is connected to a thermal over-current protection circuit
that disconnects the input when an overcurrent occurs and reconnects
the input when the condition is removed.

V, Ω, mA Input



Terminals

4WΩ Sense Terminals



Channel Status



Indicator

 Menu Name Name of the menu.

 Hazardous Voltage



Indicator

 Date and Time

 Module Indicator

 Scan/Monitor

Input terminals that connect to test leads to measure ac and dc volts,
ac and dc milliamps, hertz, and ohms.

Sense input terminals to make 3-wire and 4-wire compensated
resistance measurements.

Square green box that shows when a channel is set to ON. When a
channel is set to ON, it is referred to as “active”.

Warns the user of hazardous voltage on an input. Shows when voltage
is >30 V dc or ac rms.

Shows the current date and time that is set in the Instrument Setup
menu. This date and time is used for timestamps when data is logged.

Visually shows how many and which slots the Input Modules are
connected to. See “Input Module and Relay Card Installation” in
Chapter 2.

Scan all active channels. The Scan function samples all active
channels directed by the test setup file. The Monitor function shows
measurement data of a single channel. See Chapter 4 for more
information and operation instructions.

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Table 1-1. Front-Panel Features (cont.)

Item Name Function

Starts and stops data recording. When recording, the key illuminates and
“RECORDING” shows on the top of the display. Recording can be set to

 Record

automatically start and stop with a scan. In addition to recording scan data,
measurements made with the front-panel DMM can also be recorded. See
Chapter 4 for more information and operation instructions.

 Memory

Manage setup files, scan data files, and DMM data files on either the
internal memory or USB drive.

Digital multimeter (DMM) function that lets the user quickly configure and

 DMM

make measurements with the front-panel inputs. See Chapter 5 for DMM
operation instructions.

 Instrument Setup

Configure the Product. Menu contains many user-configurable settings to
customize the Product. See “Configure the Product” in Chapter 2.

Configure and verify channels. Channel Setup is the default menu that

 Channel Setup

shows on the display when the Product is powered on. See Chapter 3 for
instructions on how to wire and configure a channel.

Use to input numerical values when prompted. Push and hold the PRINT

 Numeric Keypad

or “0” key to take a screenshot of the display. Push and hold the LOCK key
to lock the front panel to prevent changes and UNLOCK to unlock.

Table 1-2. Rear-Panel Features

1

11

2

3

12345678 123456

4

5

6

7

8

9

10

hce002.eps

1-6

Item Name Function

Line Voltage



Selector and Fuse

Regional voltage selector. See “Set the Regional Voltage” in Chapter 2.

Product Overview and Specifications

Front and Rear-Panel Overview 1

Table 1-2. Rear-Panel Features (cont.)

Item Name Function

Main Power Switch



Mains Power



Connector

Chassis Ground



Serial USB Port



LAN Connection



Totalizer Input



DIO (Digital I/O



Input Ports)

Digital External



Alarm Trigger
Outputs

 Trigger Input

 Input Module Slots

Supplies and disconnects mains power to the unit.

Mains power cord receptacle.

Terminal that is internally grounded to the chassis. If the Product is the
location of the ground reference point in a system, this binding post can be
used to connect other instruments to earth ground.

USB port used for remote operation. See the 2638A Remote Programmers
Guide.

Network port used for remote operation. See the 2638A Remote
Programmers Guide.

Input terminal for the Totalizer feature. See “Totalizer Channel
Configuration” in Chapter 3.

Eight digital ports used to sense and output a digital, 8-bit transistor­transistor logic (TTL) value that can be displayed as the 8-bit TTL value and
be recorded as the decimal equivalent.

Six digital outputs that can be used to trigger a digital external alarm if a
channel exceeds the set alarm limits. See “HI and LO Channel Alarms” in
Chapter 3.

Input terminal to trigger a scan when the External trigger type is used. See
Scan Test Setup” in Chapter 4.

Slots that accept the Input Modules. See “Input Module and Relay Card
Installation” in Chapter 2.

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Safety Information

A Warning identifies conditions and procedures that are dangerous to the user. A
Caution identifies conditions and procedures that can cause damage to the Product or

the equipment under test.

See Table 1-3 for a list of symbols used in this manual and on the Product.

Table 1-3. Symbols

Symbol Description Symbol Description







or






CAT II

CAT III

CAT IV



Risk of danger. Important
information. See manual.

Hazardous voltage. Voltage
>30 V dc or ac peak might be
present.

AC or DC (Alternating or Direct
Current)

Earth ground.

Recycle.

Measurement Category II is applicable to test and measuring circuits connected directly to
utilization points (socket outlets and similar points) of the low-voltage MAINS installation.

Measurement Category III is applicable to test and measuring circuits connected to the
distribution part of the building’s low-voltage MAINS installation.

Measurement Category IV is applicable to test and measuring circuits connected at the source
of the building’s low-voltage MAINS installation.

This product complies with the WEEE Directive (2002/96/EC) marking requirements. The
affixed label indicates that you must not discard this electrical/electronic product in domestic
household waste. Product Category: With reference to the equipment types in the WEEE
Directive Annex I, this product is classed as category 9 "Monitoring and Control
Instrumentation” product. Do not dispose of this product as unsorted municipal waste. Go to
Fluke’s website for recycling information.











AC (Alternating Current)

DC (Direct Current)

Digital signal.

Power ON / OFF

Double insulated.

1-8



Product conforms with the requirements of the applicable EC directives.

Warning

To prevent possible electrical shock, fire, or personal injury:

• Read all safety information before you use the Product.

• Carefully read all instructions.

Product Overview and Specifications

Safety Information 1

• Use the Product only as specified, or the protection supplied

by the Product can be compromised.

• Examine the case before you use the Product. Look for cracks

or missing plastic. Carefully look at the insulation around the
terminals.

• Do not use the Product if it operates incorrectly.

• Do not use and disable the Product if it is damaged.

• Use only the mains power cord and connector approved for

the voltage and plug configuration in your country and rated
for the Product.

• Replace the mains power cord if the insulation is damaged or

if the insulation shows signs of wear.

• Make sure the ground conductor in the mains power cord is

connected to a protective earth ground. Disruption of the
protective earth could put voltage on the chassis that could
cause death.

• Do not put the Product where access to the mains power cord

is blocked.

• Use only correct measurement category (CAT), voltage, and

amperage rated probes, test leads, and adapters for the
measurement.

• Use only cables with correct voltage ratings.

• Do not use test leads if they are damaged. Examine the test

leads for damaged insulation and measure a known voltage.

• Do not exceed the Measurement Category (CAT) rating of the

lowest rated individual component of a Product, probe, or
accessory.

• Keep fingers behind the finger guards on the probes.

• Do not apply more than the rated voltage, between the

terminals or between each terminal and earth ground.

• Do not touch voltages >30 V ac rms, 42 V ac peak, or 60 V dc.

• Limit operation to the specified measurement category,

voltage, or amperage ratings.

• Measure a known voltage first to make sure that the Product

operates correctly.

1-9

2638A

Users Manual

• Consider all accessible channels to be hazardous live and an

electric shock hazard if any channel is connected to a
hazardous voltage source.

• Do not remove, touch, or change the internal wiring of

hazardous inputs until the input source is turned off.

• Remove inputs from hazardous voltage sources before an

input module is opened.

• Use the correct terminals, function, and range for

measurements.

• Use this Product indoors only.

• Do not use the Product around explosive gas, vapor, or in

damp or wet environments.

Screen Capture Feature

The Product can take a screenshot of the display and save it directly to the USB drive.

To take a screenshot of the display (see Figure 1-1):

1. Insert a USB drive in the front panel and wait for the USB Data Transfer Indicator to

show solid red.

2. Push and hold the PRINT or “0” key on the numeric keypad for 3 seconds and then

release. The display shows “File Saved”.

3. Remove the USB from the front panel and connect it to a USB drive on a PC.

4. Open the USB drive and navigate to the image folder with this path:

\\fluke\2638A\[Product Serial Number]\Image

PRINT

3 seconds

Figure 1-1. Screen Capture

=

hce059.eps

1-10

Product Overview and Specifications

About this Manual 1

About this Manual

This manual has seven chapters:

•

Chapter 1 supplies product information, safety information, contact information, and

product specifications.

•

Chapter 2 supplies information and instructions on how to set up and configure the

Product for first time use.

•

Chapter 3 supplies instructions on how to wire inputs to the Input Module then

configure the associated channel.

•

Chapter 4 supplies information and instructions on how to do a scan, monitor a

channel, and record measurement data.

•

Chapter 5 supplies instructions on how to operate the DMM function of the Product.

•

Chapter 6 supplies information on how to clean the Product and replace the fuse in

the rear of the Product.

•

Chapter 7 supplies information on error messages and how to troubleshoot the

Product.

The Product Manual Set

The Product manual set includes:

• This 2638A Users Manual that contains feature information, operation instructions,

and basic user maintenance and troubleshooting information. The Users Manual is
translated into many languages.

• The 2638A Safety Information is printed and contains important safety information for

this Product. The Safety Information is translated into many languages.

• The 2638A Remote Programmers Guide contains information on how to remotely

operate the Product. The Programmers Guide alphabetically lists all commands and
provides example code for different applications.

• The 2638A Calibration Manual contains calibration and adjustment procedures to

keep the Product within specifications.

• The 2638A Product CD contains the all the manuals in the manual set.

All manuals are online at http://www.fluke.com/ and on CD.

1-11

2638A

Users Manual

How to Contact Fluke

To contact Fluke, call one of the following telephone numbers:

• Technical Support USA: 1-800-44-FLUKE (1-800-443-5853)

• Calibration/Repair USA: 1-888-99-FLUKE (1-888-993-5853)

• Canada: 1-800-36-FLUKE (1-800-363-5853)

• Europe: [phone]

• Japan: [phone]

• Singapore: [phone]

• Anywhere in the world: [phone]

Or, visit Fluke's website at www.fluke.com.

To register your product, visit http://register.fluke.com.

To view, print, or download the latest manual supplement, visit

http://us.fluke.com/usen/support/manuals.

Calibration and Repair Information

To schedule and send the Product to Fluke for calibration or repair:

1. Contact the Fluke Service Center in your area to schedule the calibration or repair

(see “Contact Fluke”).

2. Pack and secure the Product in a shipment box with a minimum of 2 inches of

packing around the Product to prevent damage.

3. Send the Product to the Service Center.

General Specifications

Mains Voltage

100 V Setting ...................................................... 90 V to 110 V

120 V Setting ...................................................... 108 V to 132 V

220 V Setting ...................................................... 198 V to 242 V

240 V Setting ...................................................... 216 V to 264 V

Frequency .............................................................. 47 Hz to 440 Hz

Power Consumption ............................................. 36 VA peak (24 W average)

Environment Temperature

Operating ............................................................ 0 °C to 50 °C

Full accuracy ....................................................... 18 °C to 28 °C

Storage ............................................................... -20 °C to 70 °C

Warm-up ............................................................. 1 hour to full accuracy specifications

Relative Humidity (non-condensing)

Operating ............................................................ 0 °C to 28 °C <90 %

28 °C to 40 °C <75 %
40 °C to 50 °C <45 %

Storage ............................................................... -20 °C to 70 °C <95 %

Altitude

Operating ............................................................ 2,000 m

Storage ............................................................... 12,000 m

Vibration and Shock ............................................. Complies with MIL-PRF-28800F Class 3

1-12

Product Overview and Specifications

General Specifications 1

Channel Capacity

Total analog channels ........................................ 67

Voltage/resistance channels ............................... 61

Current channels ................................................ 7

Digital I/O ............................................................ 8 bits

Totalizer .............................................................. 1

Alarm outputs...................................................... 6

Trigger input ........................................................ 1

Input Protection

Front Panel ......................................................... 300 V CAT II

Rear Panel .......................................................... 150 V CAT II, 250 V rms with maximum transient voltage of 1000 V

Math Channels

Number of channels............................................ 20

Operations .......................................................... sum, difference, multiply, divide, polynomial, power, square root,

Triggers .................................................................. interval, external (trigger input), alarm, remote (bus), manual

Battery life ............................................................. 5 years

Memory

Scan data RAM................................................... 75,000 readings with timestamp

Data/Setup flash memory ................................... 20 MB

Non-volatile memory life ..................................... 5 years

USB Host Port

Standard ............................................................. 2.0, full speed

Connector type ................................................... Type A

Function .............................................................. Memory

File system .......................................................... FAT32

Memory capacity................................................. 32 GB

USB Device Port

Connector type ................................................... Type B

Class ................................................................... Instrument

Function .............................................................. Control and data transfer

Command protocol ............................................. SCPI

LAN

Function .............................................................. Control and data transfer

Network protocols ............................................... Ethernet 10/100, TCP/IP

Command protocol ............................................. SCPI

Dimensions

Height ................................................................. 150 mm

Width ................................................................... 245 mm

Depth .................................................................. 385 mm

Weight ................................................................. 6 kg (typical configuration)

Shipping Weight.................................................. 9.5 kg (typical configuration)

Conformity ............................................................. CE, CSA, IEC 61010 3

peak. These terminals are not intended for connection to mains
voltage above 150 V without external transient suppression. The
maximum input that can be applied between rear-module terminals or
between any rear-module terminal and earth ground is 250 V dc or ac
rms.

reciprocal, exponential, logarithm, absolute value, average, maximum,
minimum

rd

ed.

1-13

2638A

Users Manual

Measurement Specifications

Accuracy specifications generally are valid for 6 ½ digit resolution mode (unless otherwise noted) for front panel input
(Channel 001), after a minimum of 1-hour warm-up, and within an environment temperature range of 18 °C to 28 °C.
24-hour specifications are relative to calibration standards and assume a controlled electromagnetic environment per EN

61326. The confidence level for accuracy specifications is 99 % within 1 year of calibration (unless otherwise noted).

Scan rate (typical, depending on function and range)

Fast ..................................................................... 33 channels per second max (0.03 seconds per channel)

Medium ............................................................... 10 channels per second (0.1 seconds per channel)

Slow .................................................................... 2 channels per second (0.5 seconds per channel)

Display Resolution ................................................ 4 ½ to 6 ½ digits, depending on Sample Rate or NPLC

DC Voltage

Maximum Input ...................................................... 300 V on any range

Common Mode Rejection ..................................... 140 dB at 50 Hz or 60 Hz (1 kΩ unbalance for NPLC of 1 or greater,

±500 V peak maximum in the low lead)

Normal Mode Rejection ........................................ 55 dB for NPLC of 1 or greater and power-line frequency ±0.1 %,

±20 % of range peak maximum

Measurement Method ........................................... Multi-ramp A/D

A/D Linearity .......................................................... 2 ppm of measurement + 1 ppm off range

Input Bias Current ................................................. <30 pA at 25 °C

DC Voltage Input Characteristics

Resolution

Range Resolution

100 mV 100.0000 mV

1 V 1.000000 V

10 V 10.00000 V 1 mV

100 V 100.0000 V 10 mV 1 mV

300 V 300.000 V 100 mV 10 mV 1 mV

[1] - Input beyond ±12 V is clamped. The clamp current is up to 3 mA. 10 MΩ is default input impedance.

Fast

4½ Digits

10 μV 1 μV 0.1 μV

100 μV 10 μV 1 μV

Medium

5 ½ Digits

100 μV 10 μV

6 ½ Digits

100 μV 10 MΩ ±1 %

Slow

Input Impedance

10 MΩ or >10 GΩ

10 MΩ or >10 GΩ

10 MΩ or >10 GΩ

10 MΩ ±1 %

[1]

[1]

[1]

1-14

Product Overview and Specifications

Measurement Specifications 1

DC Voltage Accuracy

Accuracy is given as ± (% measurement + % of range).

Range

100 mV 0.0025 % + 0.003 % 0.0025 % + 0.0035 % 0.0037 % + 0.0035 % 0.0005 % + 0.0005 %

1 V 0.0018 % + 0.0006 % 0.0018 % + 0.0007 % 0.0025 % + 0.0007 % 0.0005 % + 0.0001 %

10 V 0.0013 % + 0.0004 % 0.0018 % + 0.0005 % 0.0024 % + 0.0005 % 0.0005 % + 0.0001 %

100 V 0.0018 % + 0.0006 % 0.0027 % + 0.0006 % 0.0038 % + 0.0006 % 0.0005 % + 0.0001 %

300 V 0.0018 % + 0.002 % 0.0031 % + 0.002 % 0.0041 % + 0.002 % 0.0005 % + 0.0003 %

24 Hour

(23 ±1 °C)

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

T.C./ °C

Outside

18 °C to 28 °C

DC Voltage Additional Errors

Digits NPLC Ch. x01 – x20

6 ½ 200

6 ½

6 ½

5 ½ 1 (Medium)

4 ½ 0.2 (Fast) -

4 ½ 0.02 -

100

10 (Slow)

add 2 μV

add 2 μV

add 2 μV

add 2 μV

Additional NPLC Noise

Error

-

-

-

add 0.0008 % of range

add 0.002 % of range + 12 μV

add 0.014 % of range + 17 μV

AC Voltage

AC voltage specifications are for ac sine wave signals >5 % of range. For inputs from 1 % to 5 % of range and <50 kHz,
add an additional error of 0.1 % of range. For 50 kHz to 100 kHz, add 0.13 % of range.

Maximum Input ...................................................... 300 V rms or 425 V peak or 3 × 10

less) for any range.

Measurement Method ........................................... AC-coupled true-rms. Measures the ac component of input with up to

300 V dc bias on any range.

AC Filter Bandwidth:

Slow .................................................................... 20 Hz

Fast ..................................................................... 200 Hz

Maximum Crest Factor ......................................... 5:1 at full scale

Additional Crest Factor Errors ............................ Crest factor 1-2, 0.05 % of full scale

Crest factor 2-3, 0.2 % of full scale

Crest factor 3-4, 0.4 % of full scale

Crest factor 4-5, 0.5 % of full scale

7

volts-Hertz product (whichever is

1-15

2638A

A

r

Users Manual

AC Voltage Input Characteristics

Resolution

Range Resolution

100 mV 100.0000 mV

1 V 1.000000 V

10 V 10.00000 V 1 mV 100 µV

100 V 100.0000 V 10 mV 1 mV

300 V 300.000 V 100 mV 10 mV 1 mV

4 ½

Digits

10 μV 1 μV 0.1 μV

100 μV 10 μV 1 μV

5 ½

Digits

AC Voltage Accuracy

Accuracy is given as ± (% measurement + % of range).

6 ½

Digits

10 μV

100 μV

Input Impedance

1 MΩ ±2 % shunted by 150 pF

Range Frequency

20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %

100 mV

1 V

10 V

100 V

300 V

20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %

50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %

20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %

20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %

50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %

20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %

20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %

50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %

20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %

20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %

50 kHz to 100 kHz 0.55 % + 0.08 % 0.6 % + 0.08 % 0.6 % + 0.08 % 0.05 % + 0.01 %

20 Hz to 20 kHz 0.1 % + 0.05 % 0.11 % + 0.05 % 0.11 % + 0.05 % 0.01 % + 0.005 %

20 kHz to 50 kHz 0.2 % + 0.05 % 0.22 % + 0.05 % 0.22 % + 0.05 % 0.01 % + 0.005 %

50 kHz to 100 kHz 0.55 % + 0.27 % 0.6 % + 0.27 % 0.6 % + 0.27 % 0.05 % + 0.03 %

24 Hour

(23 ±1 °C)

Additional Low Frequency Errors

Error is stated as % of reading.

Frequency

20 Hz to 40 Hz 0 % −

40 Hz to 100 Hz

100 Hz to 200 Hz

200 Hz to 1 kHz

>1 kHz

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

C Filte

20 Hz 200 Hz

0 % 0.55 %
0 %

0 %

0 %

T.C./ °C

Outside

18 °C to 28 °C

0.2 %

0.02 %

0 %

1-16

Product Overview and Specifications

Measurement Specifications 1

DC Current

Input Protection .................................................... 0.15 A / 600 V Resettable PTC

DC Current Input Characteristics

Resolution

Range Resolution

Fast

4½

Digits

100 μA

1 mA 1.000000 mA 100 nA 10 nA 1 nA

10 mA 10.00000 mA

100 mA 100.0000 mA

100.0000 µA 10 nA 1 nA 0.1 nA

1 μA

10 μA 1 μA

Medium

5 ½

Digits

100 nA 10 nA

Slow

Digits

100 nA

6 ½

Reference

Resistance

(Ohms)

1k Ω

1k Ω

10 Ω

10 Ω

DC Current Accuracy

Accuracy is given as ± (% measurement + % of range).

Range

100 μA

1 mA 0.005 % + 0.001 % 0.015 % + 0.0011 % 0.015 % + 0.0011 % 0.002 % + 0.001 %

10 mA 0.005 % + 0.003 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %

100 mA 0.005 % + 0.001 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %

24 Hour

(23 ±1 °C)

0.005 % + 0.003 % 0.015 % + 0.0035 % 0.015 % + 0.0035 % 0.002 % + 0.001 %

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

18 °C to 28 °C

DC Current Additional Errors

Digits NPLC

6 ½ 200 - -

6 ½ 100 - -

6 ½ 10 (Slow) - -

5 ½ 1 (Medium) 0.0008 % of range 0.0008 % of range

4 ½ 0.2 (Fast) 0.002 % of range + 1.2 µA 0.002 % of range + 12 nA

4 ½ 0.02 0.014 % of range + 1.7 µA 0.014 % of range + 17 nA

Additional NPLC Noise Error

for 10 mA, 100 mA

Additional NPLC Noise

Error for 100 µA, 1 mA

Burden
Voltage

<1 mV

<1 mV

<1 mV

<1 mV

T.C./ °C

Outside

AC Current

Input Protection .................................................... 0.15 A / 600 V resettable PTC

Measurement Method ........................................... AC-coupled true-rms, dc-coupled to the shunt (no blocking capacitor).

AC Filter Bandwidth:

Slow .................................................................... 20 Hz

Fast ..................................................................... 200 Hz

Maximum Crest Factor ......................................... 5:1 at full scale

Additional Crest Factor Errors ............................ Crest factor 1-2, 0.05 % of full scale

Crest factor 2-3, 0.2 % of full scale

Crest factor 3-4, 0.4 % of full scale

Crest factor 4-5, 0.5 % of full scale

1-17

2638A

A

r

Users Manual

AC Current Input Characteristics

Resolution

Range Resolution

100 μA

1 mA 1.000000 mA 100 nA 10 nA 1 nA

10 mA 10.00000 mA

100 mA 100.0000 mA

100.0000 µA 10 nA 1 nA 0.1 nA

4 ½

Digits

1 μA

10 μA 1 μA

5 ½

Digits

100 nA 10 nA

6 ½

Digits

100 nA

Reference

Resistance

1 kΩ

1 kΩ

10 Ω

10 Ω

Burden
Voltage

<10 mV (RMS)

<10 mV (RMS)

<20 mV (RMS)

<50 mV (RMS)

AC Current Accuracy

Accuracy is given as ± (% measurement + % of range). Basic accuracy specification is for a sinusoidal signal with
amplitude greater than 5 % of range. For input signals between 1 % to 5 % of range, add 0.1 % of range.

Range Frequency

100 μA

1 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %

10 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %

100 mA 20 Hz to 2 kHz 0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %

20 Hz to 2 kHz

24 Hour

(23 ±1 °C)

0.2 % + 0.06 % 0.25 % + 0.06 % 0.3 % + 0.06 % 0.015 % + 0.005 %

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

T.C./ °C Outside

18 °C to 28 °C

Additional Low Frequency Errors

Error is stated as % of reading.

Frequency

20 Hz to 40 Hz

40 Hz to 100 Hz

100 Hz to 200 Hz

200 Hz to 1 kHz

>1 kHz

20 Hz 200 Hz

0 %

0 %
0 %

0 %

0 %

C Filte

−

0.55 %

0.2 %

0.02 %

0 %

Frequency

Gate Times ............................................................. 100 milliseconds to 1 second.

Measurement Method ........................................... Flexible counting technique. AC-coupled input using the ac voltage

Settling Considerations........................................ When measuring frequency after a dc offset voltage change, errors

Measurement Considerations.............................. To minimize measurement errors, shield inputs from external noise

measurement function.

may occur. For the most accurate measurement, wait up to 1 second
for the input blocking capacitor to settle.

when measuring low-voltage, low-frequency signals.

Frequency Accuracy

Accuracy is given as ± % of measurement.

Range Frequency

100 mV to

[1] [2]

300 V

[1] Input >100 mV. For 10 mV to 100 mV, multiply percent measurement error by 10.
[2] Limited to 3 x 10

20 Hz to 40 Hz 0.03 % 0.03 % 0.03 % 0.001 %

40 Hz to 1 MHz

7

volt-Hertz

24 Hour

(23 ±1 °C)

0.006 % 0.01 % 0.01 % 0.001 %

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

T.C./ °C
Outside 18
°C to 28 °C

1-18

Product Overview and Specifications

Measurement Specifications 1

Resistance

Measurement Method ........................................... Current source referenced to LO input.

Max. Lead Resistance (4-wire ohms) .................. 10 Ω per lead for 100 Ω, 1 kΩ ranges. 1 kΩ per lead on all other

Input Protection .................................................... 300 V on all ranges.

ranges.

Resistance Input Characteristics

Resolution

Range Resolution

100 Ω 100.0000 Ω 10 mΩ 1 mΩ 0.1 mΩ

1 kΩ 1.000000 kΩ 100 mΩ 10 mΩ 1 mΩ

10 kΩ 10.00000 kΩ 1 Ω 100 mΩ 10 mΩ

100 kΩ 100.0000 kΩ 10 Ω 1 Ω 100 mΩ

1 MΩ 1.000000 MΩ 100 Ω 10 Ω 1 Ω

10 MΩ 10.00000 MΩ 1 kΩ 100 Ω 10 Ω

100 MΩ 100.0000 MΩ 10 kΩ 1 kΩ 100 Ω

Fast

4½ Digits

Medium

5 ½ Digits

Slow

6 ½ Digits

Source Current

1 mA / 4 V

1 mA / 4 V

100 µA / 6 V

100 µA / 12 V

10 µA / 12 V

1 µA / 12 V

0.1 µA / 12 V

Resistance Accuracy

Accuracy is given as ± (% measurement + % of range). Basic accuracy specification is for 4-wire resistance. For 2-wire
resistance add 0.02 Ω internal resistance if using Channel 1 or 1.5 Ω if using channels x01 through x20, and add external
lead wire resistance.

Range

100 Ω

1 kΩ

10 kΩ

100 kΩ

1 MΩ

10 MΩ

100 MΩ

24 Hour

(23 ±1 °C)

0.003 % + 0.003 % 0.008 % + 0.004 % 0.01 % + 0.004 % 0.0006 % + 0.0005 %

0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.002 % 0.0006 % + 0.0001 %

0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.002 % 0.0006 % + 0.0001 %

0.002 % + 0.0005 % 0.008 % + 0.001 % 0.01 % + 0.002 % 0.0006 % + 0.0001 %

0.002 % + 0.001 % 0.008 % + 0.001 % 0.01 % + 0.002 % 0.001 % + 0.0002 %

0.015 % + 0.001 % 0.02 % + 0.001 % 0.04 % + 0.002 % 0.003 % + 0.0004 %

0.3 % + 0.01 % 0.8 % + 0.01 % 0.8 % + 0.01 % 0.05 % + 0.002 %

Resistance Additional Errors

Digits NPLC Additional NPLC Noise Error

6 ½ 200 0 % of range
6 ½ 100 0 % of range

6 ½ 10 (Slow) 0 % of range

5 ½ 1 (Medium) 0.0008 % of range

4 ½ 0.2 (Fast)(only for 2-wire)

4 ½ 0.02 (only for 2-wire)

90 Days

(23 ±5 °C)

1 Year

(23 ±5 °C)

T.C./ °C

Outside 18 °C

to 28 °C

0.002 % of range + 12 mΩ

0.01 % of range + 17 mΩ

1-19

2638A

Users Manual

RTD

Temperature Range .............................................. -200 °C to 1200 °C (depending on the sensor)

Resistance Range ................................................. 0 Ω to 4 kΩ

Maximum Lead Resistance (4-wire Ω) ................ 2.5 % of range per lead for 400 Ω and 4 kΩ ranges

Sample Rate

Slow .................................................................... 10 PLC

Medium ............................................................... 2 PLC

Fast ..................................................................... 1 PLC

RTD Temperature Accuracy

Accuracy is for 4-wire 100 Ω nominal RTD, using the slow sample rate. With 3-wire PRT/RTD add 0.015 °C if using
Channel 1, or add 0.15 °C internal resistance mismatch to the accuracy specification if using channels x01 through x20,
and add external lead wire resistance mismatch. When using medium or fast sample rate (NPLC <10), add the number
given in the table to the accuracy specification. If the environment temperature is outside the specified range, multiply the
Temperature Coefficient number by the temperature deviation and add to the accuracy specification. Linear interpolation
may be used between points in the table. Specifications do not include sensor accuracy. The practical range of
temperature measurement depends on the sensor and characterization.

Temperature Accuracy

-200 °C 0.016 °C add 0.02 °C 0.0026 °C

0 °C 0.038 °C add 0.02 °C 0.0041 °C

300 °C 0.073 °C add 0.03 °C 0.0063 °C

600 °C 0.113 °C add 0.03 °C 0.0089 °C

Medium/Fast Sample

Rate (NPLC <10)

T.C./ °C Outside

RTD Measurement Characteristics

Temperature Display Resolution

Range

0 Ω to 400 Ω

400 Ω to 4 kΩ

Slow

Sample Rate

0.001 °C 0.01 °C

0.001 °C 0.01 °C

Medium/Fast
Sample Rate

Thermistor

Temperature Range .............................................. -200 °C to 400 °C (depending on the sensor)

Resistance Range ................................................. 0 Ω to 1 MΩ

Sample Rate

Slow .................................................................... 10 PLC

Medium ............................................................... 2 PLC

Fast ..................................................................... 1 PLC

18 °C to 28 °C

Source Current

1 mA

0.1 mA

1-20