Fluke 5618B Operating Manual

5618B

Small Diameter Industrial RTD

Users Guide

2004, Rev. 1, 4/11

© 2004 - 2011 Fluke Corporation. All rights reserved. Specications subject to change without notice.

All product names are trademarks of their respective companies.

Limited Warranty & 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 specications 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 difculty, 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 specied 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 Fluke Europe B.V.
P.O. Box 9090 P.O. Box 1186
Everett, WA 98206-9090 5602 BD Eindhoven
U.S.A. The Netherlands

11/99

Table of Contents

Title Page

Introduction ......................................................................................................................... 1

General ............................................................................................................................ 1

Recalibration ................................................................................................................... 1

Before You Start .................................................................................................................. 1

Symbols Used .................................................................................................................1

Safety Information .......................................................................................................... 2

How to Contact Fluke ..................................................................................................... 2

Specications ......................................................................................................................3

Installation ..........................................................................................................................4

Lead Wire Identication .................................................................................................4

PRT Care and Handling Guidelines .................................................................................... 4

Operation ............................................................................................................................5

Immersion Requirements ................................................................................................ 5

Thermal EMF .................................................................................................................. 5

Transition Junction ..........................................................................................................5

Troubleshooting ..................................................................................................................6

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5618B

Users Guide

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List of Tables

Table Title

Table 1. International Electrical Symbols ............................................................................................... 1

Table 2. Specications ............................................................................................................................ 3

Table 3. PRT Troubleshooting ...............................................................................................................6

Page

List of Figures

Figure Title Page

Figure 1. PRT Schematic ........................................................................................................................4

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5618B

Users Guide

iv

Introduction

General

The Platinum Resistance Thermometer (PRT) model 5618B is designed to be a secondary
standard interpolating instrument converting temperature to resistance. The 5618B may also
be used as a temperature standard for calibration of industrial sensors. The PRT is used with a
readout device to detect temperature changes or actual temperature.

Recalibration

Recalibration of the 5618B PRT should be scheduled according to the user’s company Quality
Assurance requirements. Normally, a PRT is recalibrated annually. Unless the PRT is used only
over a limited range, calibration over the full range of the PRT is recommended. For information
on recalibrating your PRT, contact Fluke for assistance (see “How to Contact Fluke”).

Depending on the user’s Quality Assurance requirements, the PRT drift should be checked
periodically at the Triple Point of Water (TPW). For information on drift with respect to
mechanical shock and oxidation, refer to the “Troubleshooting” section of this manual.

Before You Start

Symbols Used

Table 1 lists the International Electrical Symbols. Some or all of these symbols may be used on
the instrument or in this manual.

Table 1. International Electrical Symbols

Symbol Description Symbol Description

X
:
W

B

D

F

T

.

CAT II

Electric Shock

Hot Surface (Burn Hazard)

Read the Users Manual (Important
Information)

AC (Alternating Current)

AC-DC

DC

Double Insulated

PE Ground

CAT II equipment is designed to protect against transients from energy-consuming

equipment supplied from the xed installation, such as TVs, PCs, portable tools, and

other household appliances.

O

I

M

;

)

P



Off

On

I

Fuse

Battery

C-TICK Australian EMC Mark

Canadian Standards Association

CE Complies with European Union

Directives

The European Waste Electrical
and Electronic Equipment (WEEE)
Directive (2002/96/EC) Mark

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5618B

Users Guide

Safety Information

Use this instrument only as specied in this manual. Otherwise, the protection provided by the

instrument may be impaired.

The following denitions apply to the terms “Warning” and “Caution”.

• “Warning” identies conditions and actions that may pose hazards to the user.

• “Caution” identies conditions and actions that may damage the instrument being used.

To avoid personal injury, follow these guidelines:

• DO NOT use this instrument to measure the temperature of any hazardous
live component (>30 V ac rms, 42 V ac peak, or 60 V dc).

• Use of this instrument at high temperatures for extended periods of time can
cause the handle to become hot.

• Follow all safety guidelines listed in the Users Guide.

• Calibration Equipment should only be used by trained personnel.

• UsetheProductonlyasspecied,ortheprotectionsuppliedbytheProduct

can be compromised.

• DO NOT use the Product around explosive gas, vapor, or in damp or wet
environments.

Warning W

To avoid possible damage to the instrument, follow these guidelines:

• DO NOT drop or hit the probe in any way. This will cause damage to
the probe internally and affect its calibration.

• Read “PRT Care and Handling Guidelines” before removing the PRT
from the shipping box. Incorrect handling can damage the PRT and
void the warranty.

• Keep the shipping container in case it is necessary to ship the PRT.
Incorrect packaging of the PRT for shipment can cause irreparable
damage.

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.uke.com.

To register your product, visit http://register.uke.com.

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

http://us.uke.com/usen/support/manuals.

Caution W

2

Specications

See Table 2 for a list of the specications.

Temperature Range

Nominal Resistance at 0.01 °C

Temperature Coefcient 0.003923 Ω/Ω/ °C

[1]

Drift

Hysteresis

Sheath Dimensions (Length x Diameter)

Sheath Material 316 SST

Transition Junction Temperature Range

Response Time

Lead-wire Cable Type 22 AWG, Teon™ Insulation

Thermal EMF Less than 25 mV at 420 °C

Lead-wire Length 182.9 cm (72 in)

Calibration

[1] After 100 hours at maximum temperature.

[2] Temperatures outside this range will cause irreparable damage.

[3] Per ASTM E 644

Small Diameter Industrial RTD

Table 2. Specications

Parameter Range

–200 °C to 500 °C

(–200 °C to 300 °C for 5618B-6-X)

100 Ω

± 0.1 °C at 0.010 °C

± 0.01 °C at 0 °C When Using –196 °C and 420 °C
as the End Points.

5618B-6: 152 mm x 3.2 mm (6 in x 0.125 in)

5618B-9: 229 mm x 3.2 mm (9 in x 0.125 in)

5618B-12: 305 mm x 3.2 mm (12 x 0.125 in)

[2]

[3]

–50 °C to 200 °C

9 Seconds Typical

Includes Manufacturer’s NVLAP-Accredited
Calibration

Specications

3

5618B

White

Red

Users Guide

Installation

Lead Wire Identication

The 5618B PRT is equipped with a four-wire cable (see Figure 1). Four lead wires are used to
cancel lead wire resistance. For best results, the readout device should be equipped to handle
four-terminal resistors. The lead wires are two different colors. Lead wire pairs attached to each

end of the sensor are identied by red and white insulation.

White Red

5618B Lead Wires.eps

Figure 1. PRT Schematic

PRT Care and Handling Guidelines

Read this section before removing the PRT from the shipping
box or case.

Care must be taken in handling the PRT to maintain calibration accuracy. Care should still be used
when handling the PRT even though the Inconel sheath is durable and provides good protection
for the sensor. Correct handling of the PRT will prolong the life expectancy. When not in use, the
PRT should be stored in an optional protective case that can be purchased by contacting Fluke
(see “How to Contact Fluke”). The handle is not designed to be immersed.

PRT Handling Guidelines

• Keep the thermometer as clean as possible.

• Immerse the thermometer in the appropriate liquid for the temperature range. If a dry block

is used, the well diameter should allow the PRT to comfortably slip in and out without excess
movement. For best results, immerse the thermometer as deep as possible to avoid “stem
effect” (the temperature error caused by the conduction of heat away from the sensor).

• Allow sufcient time for the thermometer to stabilize before making measurements. This

allows for the best accuracy.

• Use the correct drive current with the thermometer to prevent error in temperature or
resistance. Fluke recommends 1 mA.

• Use the protective shipping box provided or other protection when the thermometer is not in
use.

• DO NOT subject the thermometer to any physical shock or vibration.

• DO NOT use pliers or other devices to squeeze the sheath. This action can permanently

damage the PRT.

• DO NOT subject the thermometer to temperatures above the highest specied operating

temperature.

• DO NOT expose the thermometer’s handle or cables to extreme temperatures.

• DO NOT screw a clamp down so tight that it dents the sheath. This can permanently damage

the PRT.

Caution W

4

Operation

For best results, be familiar with the operation of the heat source and the readout instrument. Be
sure to follow the manufacturer’s instructions for the readout instrument and the heat source.

Immersion Requirements

Stem effect can cause measurement errors for any thermometer. This error is due to heat lost or
gained by the sensing element through the thermometer stem. In addition, heat losses occur due to
radiation losses from the sensing element to the housing.

The immersion depth for standards is dependent on several factors including accuracy
requirements and type of liquid. However, remember the handle limitations.

The handle is not designed to be immersed. The exact immersion depth required can
be determined by performing a gradient test taking measurements approximately every

1.27 cm (0.5 in) until there is a signicant difference in readings. Allow the thermometer to

stabilize at each new depth. Plot the results to see the stem effect.

Thermal EMF

Two factors contribute to thermal EMF, chemical consistency and physical consistency. Variations
in chemical structure due to impurities can contribute to thermal EMF. Also discrepancies in
crystal structure can contribute to thermal EMF. These factors are minimized by annealing the full
length of wire before construction of the PRT.

Likewise, connection to extension lead wires and readout instruments can be a source of thermal
EMF. The thermal EMF is caused by a difference in temperature between two connections. If the
two connections are the same temperature, there will be little or no thermal EMF effects.

However, if there is a substantial temperature difference between connections, the thermal EMF

effects will be signicant. Therefore, cover or insulate any exposed bridge or galvanometer

terminals to lessen the source of error. The effects of thermal EMF can be canceled by using an ac
bridge or a dc bridge with reversible current.

Small Diameter Industrial RTD

Operation

Transition Junction

The transition junction has the appearance of a probe handle but functions as a transition point
from sensor wire to lead wire. Lead wires pass through an epoxy seal and are soldered or welded
to the sensor wires. Exceeding the temperature range of the transition junction will cause a breach
in the seal of the instrument (see Transition Junction Temperature Range in Table 2) Maintaining
the seal is critical to preventing moisture from entering the device. If moisture penetrates the seal,
the PRT’s short term repeatability, hysteresis, and insulation resistance may be adversely affected.
Insulation resistance also decreases rapidly as the transition junction temperature increases, even

if the seal is not broken. When the insulation resistance becomes sufciently low, performance

suffers.

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5618B

Users Guide

Troubleshooting

In the event that the probe appears to function abnormally, this section may be of use in solving
the problem. Several possible problem conditions are described along with likely causes and
solutions. If a problem arises, please read this section carefully and attempt to understand and
solve the problem. If the probe seems faulty or the problem cannot otherwise be solved, contact
Fluke for assistance (see “How to Contact Fluke”). Be sure to have the model number and serial
number of your probe available.

Problem Solution

Data changes greater than 0.1 °C

are observed.

Data changes less than 0.1 °C. Slight mechanical shock can cause temperature errors less than 0.1 °C.

Data unstable. If the data is unstable at the Triple Point of Water (TPW), check

Temperature readout is different

than expected. For example, the

heat source is set at 150 °C, the
PRT measures 125 °C.

Table 3. PRT Troubleshooting

Mechanical shock can cause temperature errors as great as 0.5 °C. If

this is observed, rst measure and record the R

connections for evidence of a bad connection. If the connector appears
to be in good condition and the connections are good, the PRT may be

damaged. Contact Fluke for assistance (see “How to Contact Fluke”).

• If the data is unstable at high temperatures, it may be due to electrical
noise in the system. Reduce the temperature and observe the data.
If it is stable, electrical noise is interfering with the measurements at
high temperatures. Also, this is usually due to low shunt resistance.
The resistance between the leads and the sheath (shunt resistance or
insulation resistance) as measured by a resistance meter should be
greater than 500 MΩ at room temperature. Check the grounding of the

readout device and the heat source. A faulty ground on either device

could interfere with high temperature measurements. A ground wire

attached to the metal sheath of the PRT may help to reduce electrical
noise interference.

Measure the PRT resistance at TPW.

• If the resistance of the PRT is less than the rated resistance. For
example, 98 Ω for a 100 Ω PRT indicates there may be a short in the

sensor.

• If the resistance of the PRT is only a few ohms, there may be a short
in the four lead-wires.

• If the PRT is open, the resistance will be “Out of Limits” or in the

kilohm or megohm range.

For more information or assistance, Contact Fluke (see “How to

Contact Fluke”).

tpw

.

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