Fluke 7103 Operating Manual

7103

Micro-Bath

User’s Guide

PN 3729337
December 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

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

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

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

1.2.1 Warnings ...................................................................................................2

1.2.2

1.3 Authorized Service Centers ..................................................................... 5

Cautions ....................................................................................................4

2 Introduction .............................................................................7

3 Specications and Environmental Conditions ......................9

3.1 Specifications ........................................................................................... 9

3.2 Environmental Conditions ........................................................................ 9

4 Quick Start ..............................................................................11

4.1 Unpacking .............................................................................................. 11

4.2 Setup ...................................................................................................... 11

4.3 Power ..................................................................................................... 12

4.4 Setting the Temperature ......................................................................... 12

5 Installation .............................................................................13

5.1 Bath Environment .................................................................................... 13

5.2 “Dry-out” Period ...................................................................................... 13

5.3 Bath Preparation and Filling ................................................................... 13

5.4 Power ..................................................................................................... 14

6 Bath Use .................................................................................15

6.1 General .................................................................................................. 15

6.2 Comparison Calibration ......................................................................... 15

6.3 Calibration of Multiple Probes ................................................................. 16

7 Parts and Controls ................................................................17

7.1 Back Panel ............................................................................................. 17

7.2 Front Panel ............................................................................................. 18

7.3 Accessories ........................................................................................... 19

7.3.1 Transport/Pour Access Lid ...........................................................................19

iii

7.3.2 Access Cover ...............................................................................................19

7.3.3 Probe Basket ................................................................................................20

7.3.4 Stir Bar ..........................................................................................................20

8 General Operation ..................................................................21

8.1 Changing Display Units .......................................................................... 21

8.2 Switching to 230V Operation .................................................................. 21

8.3 Bath Fluid ............................................................................................... 21

8.3.1 Temperature Range .......................................................................................21

8.3.2 Viscosity ........................................................................................................ 22

8.3.3 Specific Heat ................................................................................................. 22

8.3.4 Thermal Conductivity ....................................................................................22

8.3.5 Thermal Expansion........................................................................................22

8.3.6 Electrical Resistivity .......................................................................................22

8.3.7 Fluid Lifetime ................................................................................................. 23

8.3.8 Safety ............................................................................................................23

8.3.9 Cost ...............................................................................................................23

8.3.10 Commonly Used Fluids .................................................................................23

8.3.10.1 Water (Distilled) ................................................................................................... 24

8.3.10.2 Mineral Oil ............................................................................................................ 24

8.3.10.3 Silicone Oil (Dow Corning 200.05, 200.10, 200.20) ............................................. 24

8.3.11 Fluid Characteristics Charts ..........................................................................24

8.3.11.1 Limitations and Disclaimer .................................................................................. 25

8.3.11.2 About the Graph .................................................................................................. 26

8.4 Stirring .................................................................................................... 27

8.5 Power ..................................................................................................... 28

8.6 Thermal Electric Devices (TED) ............................................................. 28

8.7 Fluid Drain .............................................................................................. 28

8.8 Temperature Controller .......................................................................... 28

9 Controller Operation .............................................................31

9.1 Well Temperature ................................................................................... 31

9.2 Temperature Set-point ........................................................................... 31

9.2.1 Programmable Set-points ............................................................................31

9.2.2 Set-point Value .............................................................................................33

9.2.3 Temperature Scale Units ..............................................................................33

9.3 Scan ....................................................................................................... 34

9.3.1 Scan Control ................................................................................................. 34

9.3.2 Scan Rate .....................................................................................................34

9.4 Temperature Display Hold ..................................................................... 35

iv

9.4.1 Hold Temperature Display ............................................................................35

9.4.2 Mode Setting ................................................................................................35

9.4.3 Switch Wiring ................................................................................................ 36

9.4.4 Switch Test Example ....................................................................................36

9.5 Secondary Menu .................................................................................... 36

9.6 Thermal Electric Device (TED) ............................................................... 36

9.7 Proportional Band .................................................................................. 37

9.8 Controller Configuration .......................................................................... 38

9.8.1 Operating Parameters ...................................................................................38

9.8.1.1 High Limit ............................................................................................................39

9.8.1.2 Stir Speed ............................................................................................................39

9.8.2 Serial Interface Parameters .......................................................................... 39

9.8.2.1 Baud Rate ............................................................................................................. 40

9.8.2.2 Sample Period ...................................................................................................... 40

9.8.2.3 Duplex Mode ........................................................................................................ 40

9.8.2.4 Linefeed ............................................................................................................... 41

9.8.3 Calibration Parameters ..................................................................................41

9.8.3.1 Hard Cutout ......................................................................................................... 42

9.8.3.2 R0 ........................................................................................................................ 42

9.8.3.3 ALPHA .................................................................................................................42

9.8.3.4 DELTA .................................................................................................................. 42

9.8.3.5 BETA .................................................................................................................... 42

10 Digital Communication Interface ..........................................43

10.1 Serial Communications .......................................................................... 43

10.1.1 Wiring ...........................................................................................................43

10.1.2 Setup ............................................................................................................43

10.1.2.1 Baud Rate ........................................................................................................... 44

10.1.2.2 Sample Period ...................................................................................................... 44

10.1.2.3 Duplex Mode ........................................................................................................ 44

10.1.2.4 Linefeed ................................................................................................................ 44

10.1.3 Serial Operation ............................................................................................ 44

10.2 Interface Commands .............................................................................. 45

11 Test Probe Calibration ...........................................................47

11.1 Calibrating a Single Probe ..................................................................... 47

11.2 Stabilization and Accuracy .................................................................... 47

12 Calibration Procedure ...........................................................49

12.1 Calibration Points ................................................................................... 49

v

12.2 Calibration Procedure ............................................................................ 49

12.2.1 Compute DELTA ...........................................................................................49

12.2.2 Compute R0 & ALPHA ..................................................................................50

12.2.3 Compute BETA ..............................................................................................50

12.2.4 Accuracy & Repeatability ............................................................................. 51

13 Maintenance ..........................................................................53

14 Troubleshooting .....................................................................55

14.1 Troubleshooting Problems, Possible Causes, and Solutions ................. 55

14.2 Comments ............................................................................................... 56

14.2.1 EMC Directive ............................................................................................... 56

14.2.2 Low Voltage Directive (Safety) ......................................................................56

vi

Tables

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

Table 2 Specifications ....................................................................................... 9

Table 3 Table of Various Bath Fluids ............................................................... 25

Table 4 Nominal Stirrer Motor Settings With Different Liquids ........................ 27

Table 5 Controller Communications Commands ............................................. 46

vii

Figures

Figure 1 7103 Back Panel and Bottom ............................................................ 17

Figure 2 7103 Front Panel ................................................................................ 18

Figure 3 Bath Lids and Lid Parts ..................................................................... 19

Figure 4 Probe Basket ..................................................................................... 20

Figure 5 Stir Bar .............................................................................................. 20

Figure 6 Chart of Various Bath Fluids ............................................................. 26

Figure 7 Controller Operation Flowchart ......................................................... 32

Figure 8 Serial Cable Wiring ........................................................................... 43

viii

Before You Start

Symbols Used

Before You Start1

Symbols Used1.1

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

AC (Alternating Current)

AC-DC

Battery

CE Complies with European Union directives

DC

Double Insulated

Electric Shock

Fuse

PE Ground

Hot Surface (Burn Hazard)

Read the User’s Guide (Important Information)

Off

On

Canadian Standards Association

1

7103 Micro-Bath User’s Guide

Safety Information

Symbol Description

OVERVOLTAGE (Installation) CATEGORY II, Pollution Degree 2 per IEC1010-1 re fers to
the level of Impulse Withstand Voltage protection provided. Equipment of OVERVOLTAGE
CATEGORY II is energy-consuming equipment to be supplied from the xed installation.
Examples include household, office, and laboratory appliances.

C-TICK Australian EMC mark

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

Safety Information 1.2

Use this instrument only as specified in this manual. Otherwise, the protection
provided by the instrument may be impaired.

The following definitions apply to the terms “Warning” and “Caution”.

L

“Warning” identifies conditions and actions that may pose hazards to the user.

L

“Caution” identifies conditions and actions that may damage the instru ment
being used.

1.2.1 Warnings

Disclaimer: Hart Scientific manufactures instruments for the purpose of
temperature calibration. Instruments used for applications other than

calibration are used at the discretion and sole responsibility of the customer.
Hart Scientific cannot accept any responsibility for the use of instruments for
any application other than temperature calibration.

GENERAL
DO NOT use the instrument for any application other than calibration work.

The instrument was designed for temperature calibration. Any other use of the unit
may cause unknown hazards to the user.

DO NOT use the unit in environments other than those listed in the user’s guide.
Completely unattended operation in not recommended.
DO NOT install access cover without holes onto a bath that is energized. Dangerous

pressures may result from fluids vaporizing.
Follow all safety guidelines listed in the user’s manual.

2

Before You Start

Safety Information

Calibration Equipment should only be used by Trained Personnel.
If this equipment is used in a manner not specified by the manufacturer, the protection

provided by the equipment may be impaired or safety hazards may arise.
Inspect the instrument for damage before each use. DO NOT use the instru ment if it

appears damaged or operates abnormally.
Before initial use, or after transport, or after storage in humid or semi-humid

environments, or anytime the instrument has not been energized for more than 10
days, the instrument needs to be energized for a “dry-out” period of 2 hours before
it can be assumed to meet all of the safety requirements of the IEC 61010-1. If the
product is wet or has been in a wet environment, take necessary measures to remove
moisture prior to applying power such as storage in a low humidity temperature
chamber operating at 50°C for 4 hours or more.

The instrument is intended for indoor use only.
Lift the instrument by the handle provided to move the instrument. DO NOT move

the instrument until the display reads less than 25°C (77°F) and the unit has been
drained or the Transport Lid installed.

BURN HAZARD
ALWAYS ensure the instrument is COOL before closing the instrument for storage.

DO NOT mix water and oil when exceeding temperatures of 90°C (194°F).
DO NOT touch the well access surface of the unit.
The temperature of the well access is the same as the actual temperature shown on

the display, e.g. if the unit is set at 125°C and the display reads 125°C, the well is at
125°C.

Ensure the power cord is positioned in such a way as it cannot contact hot sur faces
or temperature probes. Always inspect power cord before use for any damage to the
insulation due to contact with hot surfaces, cuts or abrasions.

The top sheet metal of the instrument may exhibit extreme temperatures for ar eas
close to the well access.

DO NOT turn off the unit at temperatures higher than 100°C. This could create a
hazardous situation. Select a set-point less than 100°C and allow the unit to cool
before turning it off.

DO NOT remove the fluid at high temperatures. The fluid will be the same
temperature as the display temperature.

DO NOT operate near flammable materials. Extreme temperatures could ignite the
flammable material.

Use of this instrument at HIGH TEMPERATURES for extended periods of time
requires caution.

3

7103 Micro-Bath User’s Guide

Safety Information

ELECTRICAL HAZARD

These guidelines must be followed to ensure that the safety mechanisms in this
instrument will operate properly. This instrument must be plugged into a 115 VAC
(± 10%) or 230 VAC (± 10%) 50/60 Hz only electric outlet as indicated on the back
panel. The power cord of the instrument is equipped with a three-pronged grounding
plug for your protection against electrical shock haz ards. It must be plugged directly
into a properly grounded three-prong recepta cle. The receptacle must be installed
in accordance with local codes and ordinances or adapter plug. DO NOT use an
extension cord. Consult a qualified electrician. Always inspect the power cord
before use for any damage to the in sulation due to contact with hot surfaces, cuts or
abrasions.

The instrument is equipped with operator accessible fuses. If a fuse blows, it may
be due to a power surge or failure of a component. Replace the fuse once. If the fuse
blows a second time, it is likely caused by failure of a component part. If this occurs,
contact a Hart Scientific Authorized Service Center. Always replace the fuse with
one of the same rating, voltage, and type. Never replace the fuse with one of a higher
current rating.

Always replace the power cord with an approved cord of the correct rating and type. If
you have questions, contact a Hart Scientific Authorized Service Center (see Section

1.3).
High voltage is used in the operation of this equipment. Severe injury or death may

result if personnel fail to observe the safety precautions.

1.2.2 Cautions

Always operate this instrument at room temperatures listed in Section 3.2,
Environmental Conditions. Allow sufficient air circulation by leaving at least 6 inches
(15 cm) of clearance around the instrument.

Overhead clearance is required. DO NOT place this instrument under a cabinet or
other structure.

Never introduce any foreign material into the well.
DO NOT change the values of the calibration constants from the factory set values.

The correct setting of these parameters is important to the safety and proper operation
of the unit.

DO NOT slam the probe stems into the well. This type of action can cause a shock to
the sensor and affect the calibration.

DO use a ground fault interrupt device.
DO NOT operate this instrument in an excessively wet, oily, dusty, or dirty

environment.

4

Before You Start

Authorized Service Centers

The unit is a precision instrument. Although it has been designed for optimum
durability and trouble free operation, it must be handled with care.

Most probes have handle temperature limits. Be sure that the probe handle tem perature
limit is not exceeded in the air above the instrument.

The instrument and any thermometer probes used with it are sensitive instru ments that
can be easily damaged. Always handle these devices with care. Do not allow them to
be dropped, struck, stressed, or overheated.

When calibrating PRTs always follow correct calibration procedure and cali brate
from high temperatures to low temperatures with the appropriate triple point of water
checks.

Components and heater lifetimes can be shortened by continuous high tempera ture
operation.

If a mains supply power fluctuation occurs, immediately turn off the bath. Power
bumps from brown-outs and black-outs can damage the instrument. Wait until the
power has stabilized before re-energizing the bath.

Fluids may expand at different rates. Allow for fluid expansion inside the well as
the instrument heats. Otherwise, the fluid may overflow the well and leak into the
instrument.

1.3 Authorized Service Centers

Please contact one of the following authorized Service Centers to coordinate service
on your Hart product:

Fluke Corporation

Hart Scientific Division

799 E. Utah Valley Drive
American Fork, UT 84003-9775
USA

Phone: [phone]
Telefax: +1.801.763.1010
E-mail: support@hartscientific.com

5

7103 Micro-Bath User’s Guide

Authorized Service Centers

Fluke Nederland B.V.

Customer Support Services
Science Park Eindhoven 5108
5692 EC Son
NETHERLANDS

Phone: [phone]
Telefax: [phone]
E-mail: ServiceDesk@fluke.nl

Fluke Int’l Corporation

Service Center - Instrimpex
Room 2301 Sciteck Tower
22 Jianguomenwai Dajie
Chao Yang District
Beijing 100004, PRC
CHINA

Phone: [phone]
Telefax: [phone]
E-mail: xingye.han@fluke.com.cn

Fluke South East Asia Pte Ltd.

Fluke ASEAN Regional Office
Service Center
60 Alexandra Terrace #03-16
The Comtech (Lobby D)
118502
SINGAPORE

Phone: [phone]
Telefax: [phone]
E-mail: anthony.ng@fluke.com

When contacting these Service Centers for support, please have the following
information available:

L

Model Number

L

Serial Number

L

Voltage

L

Complete description of the problem

6

Introduction

Introduction 2

The Hart Scientific 7103 Micro-Bath may be used as a portable instrument or bench
top temperature calibrator for calibrating thermocouple and RTD temper ature probes.
The 7103 is small enough to use in the field, and accurate enough to use in the lab.
With an ambient temperature of 23°C (74°F), calibrations may be done over a range
of -30°C to 125°C (-22°F to 257°F). The resolution of the 7103 temperature display is

0.01 degrees.
The Micro-Bath calibrator features:

L

Convenient handle

L

RS-232 interface

L

Switchable AC Input (115 VAC or 230 VAC)

Built in programmable features include:

L

Temperature scan rate control

L

Temperature switch hold

L

Eight Set-point memory

L

Adjustable readout in °C or °F

The temperature is accurately controlled by Hart’s hybrid analog/digital con troller. The
controller uses a precision platinum RTD as a sensor and controls the well temperature
with thermal electric devices (TED).

The LED front panel continuously shows the current well temperature. The
temperature may be easily set with the control buttons to any desired tempera ture
within the specified range. The calibrator’s multiple fault protection de vices insure
user and instrument safety and protection.

The 7103 Micro-Bath was designed for portability, low cost, and ease of opera tion.
Through proper use, the instrument will continuously provide accurate calibration
of temperature sensors and devices. The user should be familiar with the safety
guidelines and operating procedures of the calibrator as de scribed in the instruction
manual.

7

Specications and Environmental Conditions3

3.1 Specications

Table 2 Specifications

Range -30 to 125°C (-22 to 257°F)

Accuracy ±0.25°C

Stability ±0.03°C at -25°C (oil, 5010)

Uniformity ±0.02°C

Resolution 0.01°C/F

Operating Temperature 5 to 45°C (41 to 113°F)

Heating Time 25°C to 100°C: 35 minutes

Cooling Time 25°C to –25°C: 45 minutes

Well Size 2.5" dia. x 5.5" deep (64 x 139 mm)

Size 9" W x 13.2" H x 10.5" D (23 x 34 x 26 cm)

Weight 22 lb. (10 kg) with uid

Display LED, Switchable °C or °F

Cooling Fan and Thermal Electric Devices (TED)

Fault Protection Sensor burnout and short protection

Power 94 – 234 VAC (±10%), 50/60 Hz, 400 W

Safety Overvoltage (Installation) Category II, Pollution Degree 2 per IEC 61010-01

Fuse Rating 250 V 5 A F(fast acting) NO USER SERVICEABLE PARTS

Specications and Environmental Conditions

Specications

±0.05°C at 125°C (oil, 5010)

(access opening is 1.9" [48 mm] in diameter)

3.2 Environmental Conditions

Although the instrument has been designed for optimum durability and trou ble-free
operation, it must be handled with care. The instrument should not be operated in an
excessively dusty or dirty environment. Maintenance and clean ing recommendations
can be found in the Maintenance Section of this manual.

The instrument operates safely under the following conditions:

L

ambient temperature range: 5 – 45°C (41 – 113°F)

L

ambient relative humidity: maximum 80% for temperature <31°C, de creasing
linearly to 50% at 40°C

L

mains voltage within ± 10% of nominal

L

vibrations in the calibration environment should be minimized

L

altitudes less than 2,000 meters

9

Quick Start4

Caution: READ SECTION 6 ENTITLED BATH USE before placing the bath in
service. Incorrect handling can damage the bath and void the war ranty.

4.1 Unpacking

Unpack the Micro-Bath carefully and inspect it for any damage that may have
occurred during shipment. If there is shipping damage, notify the carrier immediately.

Verify that the following components are present:

L

7103 Micro-Bath

L

Transport/Pour Access Lid

L

Probe Basket

L

Stir Bar

L

Power Cord

L

Manual

Access Cover, if purchasedL

Quick Start

Unpacking

Setup 4.2

Caution: DO NOT operate the instrument without fluid.

Place the calibrator on a flat surface with at least 6 inches of free space around the
instrument. Plug the power cord into a grounded mains outlet. Observe that the
nominal voltage corresponds to that indicated on the back of the calibrator.

Carefully insert the probe basket into the well. Fill the well with the appropriate fluid.
The set-point temperature and the number of and size of probes deter mine the fluid
level. Be sure to keep the fluid level an adequate distance below the top of the well
to prevent overflowing the fluid when the probes are in serted. For example, placing

200.05 oil at room temperature (25°C) into the bath and heating the unit to 126°C,
causes a 1-inch (2.54 cm) expansion of the fluid inside the well.

Keep the fluid level at least 1.9 cm (0.75 inches) below the top of the well at all
times. With the probe (probes) in the well fill the tank 3/4 full. Heat to the maximum

temperature of the fluid. Slowly fill the well to 2.54 cm (1 inch) be low the top of the
basket at the maximum temperature of the fluid, or to the second ring on the basket.

11

7103 Micro-Bath User’s Guide

Power

Turn on the power to the calibrator by toggling the switch on the power entry module.
The fan should begin blowing air through the instrument and the con troller display
should illuminate after 3 seconds. After a brief self test the con troller should begin
normal operation. If the unit fails to operate please check the power connection.

The display shows the well temperature and the well TEDs start operating to bring
the temperature of the well to the set-point temperature. Insure that the fluid is being
stirred.

Power 4.3

Plug the Micro-Bath power cord into a mains outlet of the proper voltage, fre quency,
and current capability. Refer to Section 3.1, Specifications, for power details.

Turn the bath on using the rear panel “POWER” switch. The Micro-Bath will turn on
and begin to heat to the previously programmed temperature set-point. The front panel
LED display will indicate the actual bath temperature.

Setting the Temperature 4.4

Section 9.2 explains in detail how to set the temperature set-point on the cali brator
using the front panel keys. The procedure is summarized here.

Press “SET” twice to access the set-point value. 1.

Press “UP” or “DOWN” to change the set-point value. 2.

Press “SET” to store the new set-point. 3.

Press “EXIT” to return to the temperature display. 4.

When the set-point temperature is changed the controller switchs the well heater on
or off to raise or lower the temperature. The displayed well tempera ture gradually
changes until it reaches the set-point temperature. The well may require 90 minutes
to reach the set-point depending on the span. Another 10 to 15 minutes is required to
stabilize within ±0.04°C of the set-point. Ultimate sta bility may take 20 to 30 minutes
more of stabilization time.

12