Fluke 9230 User guide

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Page 1

9230

Hart Scientific

Gallium Cell

Maintenance System

User’s Guide

Rev. 992801

Page 2

Fluke Corporation, Hart Scientific Division

799 E. Utah Valley Drive • American Fork, UT 84003-9775 • USA Phone: +1.801.763.1600 • Telefax: +1.801.763.1010 E-mail: support@hartscientific.com

www.hartscientific.com

Rev. 992801

Page 3

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

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

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

1.2.1 WARNINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1.2.2 CAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3 Authorized Service Centers. . . . . . . . . . . . . . . . . . . . . . 4

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

3 Specifications and Environmental Conditions . . . . . . . . . . 9

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

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

3.3 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Quick Start in Auto Program Mode. . . . . . . . . . . . . . . 11

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

4.2 Set Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.3 Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.4 Auto Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4.1 Starting the Auto Program . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4.2 Generating the Melt Plateau . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4.3 Refreezing the Gallium Cell . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.4.4 Return to Standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5 Parts and Controls . . . . . . . . . . . . . . . . . . . . . . . . 15

5.1 Bottom Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.3 Top Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.4 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.5 Thermal Block Assembly . . . . . . . . . . . . . . . . . . . . . . 18

6 Controller Operation . . . . . . . . . . . . . . . . . . . . . . . 21

6.1 Standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

6.2 Starting the Auto Program . . . . . . . . . . . . . . . . . . . . . 21

6.3 Auto Program – Initiating and Maintaining the Gallium

Melt Plateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Page 4

6.4 Auto Program – Ending the Gallium Melt Plateau and

Refreezing the Cell . . . . . . . . . . . . . . . . . . . . . . . . . 24

6.5 Return to Standby . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.6 Program Advance . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.7 Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

6.8 Starting the Manual Mode. . . . . . . . . . . . . . . . . . . . . . 26

6.9 Temperature Set-point . . . . . . . . . . . . . . . . . . . . . . . . 27

6.9.1 Programmable Set-points . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.9.2 Set-point Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.10 Temperature Scale Units . . . . . . . . . . . . . . . . . . . . . . 28

6.11 Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.11.1 Scan Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.12 Scan Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.13 Temperature Scale Units . . . . . . . . . . . . . . . . . . . . . . 30

6.14 Secondary Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . 30

6.15 Peltier Device Power . . . . . . . . . . . . . . . . . . . . . . . . 30

6.16 Set-point Resistance . . . . . . . . . . . . . . . . . . . . . . . . . 30

6.17 Proportional Band . . . . . . . . . . . . . . . . . . . . . . . . . . 31

6.18 Controller Configuration, Operating, and Calibration Parameters . 32

6.19 Auto Program Configuration Parameters . . . . . . . . . . . . . . 33

6.20 Prog 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

6.20.1 Ready Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.20.2 Prep Melt Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

6.20.3 Prep Scan Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.20.4 Beeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

6.20.5 Prep 1 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

6.20.6 Prep 2 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.20.7 Prep 3 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

6.21 Prog 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

6.21.1 Maintain Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

6.21.2 Maintain Time-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

6.21.3 Maintain Time-out Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

6.21.4 Freeze Hot Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

6.21.5 Freeze Hot Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.21.6 Freeze Cold Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.21.7 Freeze Cold Scan Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6.21.8 Freeze Cold Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

6.22 Prog 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.22.1 Freeze Melt State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.23 Serial Interface Parameters . . . . . . . . . . . . . . . . . . . . . 45

6.23.1 BAUD Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.23.2 Sample Period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.23.3 Duplex Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Page 5

6.23.4 Linefeed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.24 Calibration Parameters . . . . . . . . . . . . . . . . . . . . . . . 47

6.24.1 R0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

7 Digital Communication Interface . . . . . . . . . . . . . . . . 49

7.1 Serial Communications . . . . . . . . . . . . . . . . . . . . . . . 49

7.1.1 Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.1.2 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

7.1.2.1 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

7.1.2.2 Sample Period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.1.2.3 Duplex Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.1.2.4 Linefeed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.1.3 Serial Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

7.2 Interface Commands . . . . . . . . . . . . . . . . . . . . . . . . 51

8 Melting Point of Gallium Realization . . . . . . . . . . . . . . 55

8.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

8.2 Preparing the Model 9230 to Receive the Gallium Cell. . . . . . . 56

8.3 Preparing the Frozen Model 5943 Gallium Cell for

Installation in the Model 9230 . . . . . . . . . . . . . . . . . . . 57

8.4 Installing the Frozen Model 5943 Gallium Cell into the

Model 9230 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

8.5 Inserting the Top Insulation Plugs . . . . . . . . . . . . . . . . . . 58

8.6 Inserting the Inner Melt Heater . . . . . . . . . . . . . . . . . . . 58

8.7 Auto Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

8.7.1 Starting the Auto Program . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

8.7.2 Generating the Melt Plateau and Removing the Inner Melt Heater . . . . . . 59

8.7.3 Calibrating Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

8.7.4 Advancing the Auto Program and Refreezing the Gallium Cell . . . . . . . . 60

8.7.5 Return to Standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

9 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . 61

9.1 Calibration Equipment . . . . . . . . . . . . . . . . . . . . . . . 61

9.2 Calibration Procedure . . . . . . . . . . . . . . . . . . . . . . . . 61

10 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

11 Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . 67

11.1 Troubleshooting Problems, Possible Causes, and Solutions . . . . 67

11.2 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

11.2.1 EMC Directive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

11.2.2 Low Voltage Directive (Safety) . . . . . . . . . . . . . . . . . . . . . . . . . 68

iii

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Figures and Tables

Table1 International Electrical Symbols . . . . . . . . . . . . . . . . . . . . . 1

Figure 1 Auto Program Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 2 Bottom Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 3 Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 4 Top Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 5 Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 6 Controller Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 2 Default Programmable Set-points (Factory Set) . . . . . . . . . . . . . 28

Table 3 Auto Program Parameters (Prog 1, Prog 2, Prog 3) . . . . . . . . . . . 34

Figure 7 Serial Cable Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 4 Serial Interface Commands . . . . . . . . . . . . . . . . . . . . . . . 52

Page 7

1 Before You Start

1.1 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.

Tabl e1 International Electrical Symbols

Symbol Description

AC-DC

Battery

1 Before You Start

Symbols Used

Double Insulated

Electric Shock

Fuse

PE Ground

Hot Surface

Read the User’s Manual

Off

Page 8

9230 Maintenance System

User’s Guide

Canadian Standards Association

C-TIC Australian EMC Mark

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 fixed installation. Examples include household, office, and laboratory appliances.

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

1.2 Safety Information

Use of this instrument other than as specified in this manual may impair the protection provided by the instrument.

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

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

• “CAUTION” identifies conditions and actions that may damage the instrument being used.

1.2.1

WARNINGS

To avoid possible electric shock or personal injury, follow these guidelines.

BURN HAZARD – DO NOT leave the melt heater outside of the unit and en ergized. The melt heater can reach approximately 110°C if not properly in serted into the unit. Place the melt heater in the storage well located at the back of the instrument when not in use.

DO NOT operate this unit without a properly grounded, properly polarized power cord.

Use only grounded AC mains supply of the appropriate voltage to power the in

strument. Refer to Section 3.1, Specifications, for power details.

DO NOT connect this unit to a non-grounded, non-polarized outlet.

HIGH VOLTAGE is used in the operation of this equipment. SEVERE IN

JURY OR DEATH may result if personnel fail to observe safety precautions.

Before working inside the equipment, turn the power off and disconnect the power cord.

Always replace the fuse with one of the same rating, voltage, and type.

Page 9

1 Before You Start

Safety Information

Overhead clearance is required. DO NOT place this instrument under a cabinet or other structure. Additionally, at least 6 inches of space between the instru

ment and nearby objects is necessary for sufficient air circulation.

DO NOT use this unit for any application other than calibration work.

DO NOT use this unit in environments other than those listed in the user’s

guide.

DO NOT turn the unit upside down with the cell in place; the cell will fall out of the unit.

DO NOT operate near flammable materials.

DO use a ground fault interrupt device.

Before initial use, after transport, and anytime the dry-well has not been ener gized for more than 10 days, the calibrator must be energized for a dry-out pe

riod of 1 to 2 hours before it can be assumed to meet all of the safety requirements of the IEC1010-1.

Follow all safety guidelines listed in the user’s manual.

Calibration Equipment should only be used by Trained Personnel.

When the melt heater switch is in the MANUAL ON position, the melt heater is continuously energized and can get hot!

1.2.2

CAUTIONS

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

DO NOT use fluids to clean out the well.

DO NOT slam the probe stems into the entrant well of the gallium cell. The

probe could be damaged.

DO use the cell removal tool to remove the cell from the well of the instrument. Grasp the cell with a hand as soon as the cell is removed far enough from the well.

DO NOT use the removal tool to carry the cell. The removal tool is not de signed for transporting the cell.

Never introduce foreign material into the well. Fluids, etc. can leak into the cal ibrator causing damage.

DO use silicon oil or other appropriate heat transfer medium in the entrant well of the gallium cell. Be sure the transfer medium does not leak out into the well of the instrument.

DO NOT change the value of the calibration constant from the factory set value. The correct setting of this parameter is important to the safety and proper operation of the calibrator.

Page 10

9230 Maintenance System

User’s Guide

The Auto Program configuration parameters should not be adjusted under nor mal use. These parameters directly affect the melt plateau duration time and proper freezing of the gallium cell.

Insert only frozen gallium cells into the 9230. DO NOT insert a melted cell into the unit and then initiate the Auto Program. An improper freeze may occur resulting in damage to the cell.

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: +1.801.763.1600

Telefax: +1.801.763.1010

E-mail: support@hartscientific.com

Fluke Nederland B.V.

Customer Support Services

Science Park Eindhoven 5108

5692 EC Son

NETHERLANDS

Phone: +31-402-675300

Telefax: +31-402-675321

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: +86-10-6-512-3436

Page 11

1 Before You Start

Authorized Service Centers

Telefax: +86-10-6-512-3437

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: +65 6799-5588

Telefax: +65 6799-5588

E-mail: antng@singa.fluke.com

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

information available:

• Model Number

• Serial Number

• Voltage

• Complete description of the problem

Page 12

2 Introduction

The 9230 is a specialized instrument for the realization of the gallium melting point (29.7646°C). The instrument works with Hart’s 5943 stainless steel Ga cell to provide melting plateaus that can last a week (or longer). This instru ment is intended for Calibration Laboratory use and not for field applications. Internal programming of the micro-processor controller provides prepro grammed scan rates, set-points for each step in the process, dwell timing, and indication that the next step is ready. The Model 9230 is available in 100-230 VAC (±10%), 50-60 Hz.

Built in programmable features include:

Temperature scan rate control

•

Fixed-point programming with default settings for the gallium cell

•

Eight set-point memories

•

Adjustable readout in °C or °F

•

The temperature is accurately controlled by Hart’s special proportional-integral-derivative (PID)/digital controller. The controller uses a platinum RTD as a sensor and controls the well temperature with thermoelectric Peltier devices.

After properly inserting a frozen Ga cell and powering the unit on, the Model 9230 controller sets the block temperature to 25°C and the LED front panel display shows auto. The user then makes sure that the inner melt heater is attached to the back of the unit, the melt heater switch is in the Auto position, and inserts the melt heater into the entrant well of the gallium cell. When the user selects auto by pressing the SET button, the Model 9230 Auto Program begins a pre-determined program to initiate and maintain a gallium melt plateau. While in the Auto Program mode, the display shows the current process in the gallium melt cycle. During this mode the user may not change those pa rameters, which could negatively impact the gallium melt. At the end of the plateau the unit properly refreezes the cell and returns the temperature to 25°C (standby) to await the next user initiated melt.

While in the manual mode of operation, the LED front display panel continu ously shows the current well temperature. The temperature may be easily set with the control buttons to any desired temperature within the specified range. Certain parameters of the Auto Program itself may be adjusted in the manual mode of operation.

The Model 9230 was designed for high accuracy fixed-point calibration meth ods and for ease of operation. Through proper use, the instrument will continu ously provide accurate calibration of temperature sensors and devices. The user should be familiar with the safety guidelines and operating procedures of the instrument as described in this User’s Guide.

2 Introduction

Page 13

3 Specifications and Environmental Conditions

3 Specifications and Environmental

Conditions

3.1 Specifications

Operating Range 15°C to 35°C (59°F to 95°F)

Gallium Cell Uncertainty ±0.08mK, typical

Gallium Melting Plateau Duration

Display Accuracy ±0.05°C at 29.76°C

Stability ±0.02°C

Display Resolution 0.01°C or °F (0.001°C or °F in program mode)

Display Scale °C or °F, switchable

Preheat Wells 2 wells (8.2 mm diameter)

Immersion Depth 152 mm (6 inches) in gallium cell

Vertical Gradient < 0.03°C over 6 inches during cell maintenance

Fault Protection Firmware protection

Communications RS-232 included

Ambient Temperature 18°C to 28°C (65°F to 82°F)

Power Requirements 115 VAC (±10%), 60 Hz, 1.0 A or 230 VAC (±10%), 50 Hz , 0.65 A,

Exterior Dimensions 8.75” W x 10.25” D x 19.25” H (22 x 26 x 49 cm)

Weight 18 lb (8.2 kg) without cell

5days,typical

175 W maximum

Specifications

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:

•

temperature range: 18–28°C (65–82°F)

•

ambient relative humidity: 15-50%

•

pressure: 75kPa – 106kPa

•

mains voltage within ±10% of nominal

•

vibrations in the calibration environment should be minimized

•

altitudes less than 2,000 meters

Page 14

9230 Maintenance System

User’s Guide

3.3 Warranty

Hart Scientific, Inc. (Hart) warrants this product to be free from defects in ma terial and workmanship under normal use and service for a period as stated in the current product catalog from the date of shipment. This warranty extends only to the original purchaser and shall not apply to any product which, in Hart’s sole opinion, has been subject to misuse, alteration, abuse or abnormal conditions of operation or handling.

Software is warranted to operate in accordance with its programmed instruc

tions on appropriate Hart products. It is not warranted to be error free.

Hart’s obligation under this warranty is limited to repair or replacement of a product which is returned to Hart within the warranty period and is determined, upon examination by Hart, to be defective. If Hart determines that the defect or malfunction has been caused by misuse, alteration, abuse or abnormal condi tions or operation or handling, Hart will repair the product and bill the pur

chaser for the reasonable cost of repair.

To exercise this warranty, the purchaser must forward the product after calling or writing a Hart Scientific Authorized Service Center for authorization. Hart assumes NO risk for in-transit damage.

For service or assistance, please contact a Hart Scientific Authorized Service Center (see Section 1.3).

THE FOREGOING WARRANTY IS PURCHASER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OR MERCHANTABILITY, OR FITNESS FOR ANY PARTICULAR PURPOSE OR USE. HART SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAM

AGES OR LOSS WHETHER IN CONTRACT, TORT, OR OTHERWISE.

Page 15

4 Quick Start in Auto Program Mode

Unpacking

The user should read this user’s guide and be familiar with the functional per formance of the Model 9230 before using the instrument to achieve a gallium melt plateau.

4.1 Unpacking

Unpack the instrument carefully and inspect it for any damage that may have occurred during shipment. If there is shipping damage, notify the carrier imme diately. Verify that the following components are present:

Model 9230 Gallium Maintenance Apparatus

•

Melt heater

•

Power cord

•

User’s Guide

•

• Top Insulation Plugs

• Cell Removal Tool

If you are missing any item, please call a Hart Scientific Authorized Service Center.

4.2 Set Up

Place the instrument on a flat surface with at least 6 inches of free space around and 18 inches above the instrument. Avoid drafty areas. Install the power cord into the power entry module on the back of the instrument. Plug the power cord into a grounded mains outlet. Verify that the nominal voltage corresponds to that indicated on the back of the instrument.

Using the cell removal tool, carefully insert the frozen gallium cell, prepared as described in Section 9, Melting Point of Gallium Realization, into the well. (DO NOT drop it into the well.) The well must be clear of any foreign objects, dirt and grit before the cell is inserted.

Firmly place the two top insulation plugs into the well such that they rest on top of the cell. Make sure that the inner melt heater is connected to the inner melt heater connector on the back of the instrument and the melt heater switch is in the auto position. Carefully insert the melt heater through the hole in the top insulation plugs and into the entrant well of the frozen gallium cell. Make sure the inner melt heater extends to the bottom of the gallium cell entrant well.

4.3 Power

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

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9230 Maintenance System

User’s Guide

details. Turn the instrument ON using the power switch on the back of the unit. The instrument turns on and begins to approach 25°C. The front panel LED display shows auto.

4.4 Auto Program

The Model 9230 is designed to automate the gallium cell melt plateau. This is accomplished through the use of the Auto Program; a microprocessor-con trolled program that determines set temperatures, scan rates, duration times, Peltier module configurations, and melt heater controls. By controlling all of these parameters in the proper order, a temperature profile can be maintained in the block assembly that assures a uniform melt, maintains the melt over long periods of time, properly refreezes the cell and keeps the cell ready for the next melt cycle. The Auto Program is illustrated in Figure 1.

4.4.1 Starting the Auto Program

After the frozen gallium cell is properly installed in the instrument (See Section 9, Melting Point of Gallium Realization, for more details) and the unit is powered ON, the front panel LED display shows Auto. The instrument goes to 25°C and remains there until the SET button on the front panel is pressed which starts the Auto Program. The display changes to uuAit and the Auto Program begins. The unit resets to 29.27°C at a scan rate of 0.2°C/minute in accordance with the Auto Program (see Figure 1).

4.4.2 Generating the Melt Plateau

Once the unit has stabilized at 29.27°C, it waits for a minimum of 30 minutes to ensure that the gallium cell has equalized in temperature. At the end of the equalization time, the Auto Program begins to initiate the melt. The display changes to PrEP as the set temperature of the block is changed to 30.77°C. This initiates a melt on the outer surfaces of the gallium within the cell. A few minutes into the program, the unit beeps four times and the display changes to a message that flashes between prep and htr on to indicate that the inner melt heater has been turned ON. The inner melt heater remains ON for a few minutes and then shuts off as the display changes back to prep and the unit beeps eight times. The user should remove the inner melt heater at this time. Note: No damage occurs to the gallium cell if the heater is not removed, how ever, a shortening of the melt duration may result.

After the inner melt heater is powered OFF, the instrument remains at 30.77°C for a few more minutes to complete the outer melt of the gallium cell. The unit then beeps 16 times, the display changes from prep to nnaint and the block temperature resets to 29.86°C to maintain the melting gallium cell.

The user may then insert a preheated monitor thermometer to monitor the tem perature of the gallium cell. Due to the heat applied to the cell by the inner melt heater, the temperature of the cell’s entrant well is higher than the gallium melt ing point (29.7646°C) for a short period of time. Generally, after 30 to 60 min utes, the temperature of the cell’s entrant well is sufficiently stable to begin

Page 17

4 Quick Start in Auto Program Mode

0.77 2

9.86

9.27

4 beeps

melthtr=0

(ON)

8min

PREP1

6min

PREP3

User T

est

ime Duration

(galliu

ll at 29.7646

°C )

up to

6hrs

2.5 hrs

comple

tel

freeze

gallium

cell

SR = 0.2

C/m

set = 29.

86°C

25°C

16 beeps

25.00

T (°C) - block sensor

User in

ser

frozen

gal

cell and p

owers

on u

nit

set=25°C

R=OFF

frz

mlt=0

(MELT/M

INT

)

melthtr=

(OFF

)

Unit st

ays

t 25°C until U

ser

sele

cts AU

TO or MAN

using

UP/D

Nan

presses SE

it goes

into manu

al mode

MAN is se

lected

User s

elec

UTO

set=29.2

7°C

=0.2°C

/min

zmlt=0

(MELT/M

melthtr

(OF

Unit re

sat

29.27°

Cfo

30 min

to allow

lliu

cell to

stab

ilize

30 min

minimum

Unit

begins

elt

Tset=30.7

7°C

SR=0.2°C

/min

frzmlt=0

(ME

LT/MA

INT)

lthtr=1

(OFF)

4min

PREP

DISPL

Display

PREP

Display

PRE

HTR ON

splay

PRE

8 beep

melthtr=1

(OFF)

remove

elt heate

DISPL

INT

gins

freeze

Tse

t=35.0

0°C

=OFF

frzm

lt=0

(MELT/MA

INT)

melthtr=1

(OFF)

gins

freeze

et=0.00

°C

SR=

0.5°C

/min

frzm

lt=1

(FREEZ

)

melthtr=1

(OFF

)

Unit

returns

25°C

Tset=

25°C

SR=O

frzmlt=0

ELT/MA

INT)

elthtr=1

(OFF)

DISPL

FREEZEH

(OPTIONA

DISPL

FREE

Unit rem

ins

at 25°C

unti

l User

selects

AUTO

or M

(be

gin aga

in)

begin

again

DISPL

AUTO

If in

MAN

mode, User

can re

turn

to AU

TO m

ode by adva

ncin

he progra

m(SET+

DN)

25°C

.27°C

30.77°C

29.86°C

Time - as indicated above

User c

ort the

Auto

Prog

ram and

return t

ndby

Mode

(25°

)during

the "WAI

"tim

eby

adva

ncing

the

program (

SET+

DN)

Defaul

t-U

er initiates F

reez

advancing

prog

ram (SET+D

Option - U

ser pr

e-sets MAIN

Duration

ime

after which

program in

itiates

Freeze

Default -

irectly

to FreezC

(no Fr

eezH)

ption - U

ser pre-

sets

FreezH Te

mper

ature

nd Durat

ion Time

to melt ga

llium ce

fore Fre

eze

up to

36°C

Auto Program

Figure 1 Auto Program Diagram

Page 18

9230 Maintenance System

User’s Guide

calibrations of thermometer sensors. The duration of the melt plateau varies de pending on usage, but lengths of 5 days or longer are achievable.

4.4.3 Refreezing the Gallium Cell

At the end of the melt plateau (or when the user wishes to end the plateau), the Auto Program is advanced by pressing the SET and DOWN buttons (press the SET button and keep it pressed and then press the DOWN button and release both) on the front panel (program advance). The dislay will flash “AdU”and display “nnAint.” Use the UP and DOWN buttons to select the program state “FrEE2C” then press the ENTER button. See Section 6.21.2, Maintain Time-out, for optional user defined auto time-out. Gallium, like water, expands in volume when freezing. Therefore, the cell must be frozen from the bottom up or there is a potential for damage to the cell. The Auto Program process en sures that the cell is properly refrozen.

The Auto Program initiates the freeze and the display shows free2E at this point. The Peltier devices are reconfigured and controlled such that a large tem perature gradient is generated between the top and bottom of the block. The instrument slowly scans to 0°C to maintain the gradient over several hours. See Section 6.21.4, Freeze Hot Temperature, for optional user defined freeze hot temperature.

4.4.4 Return to Standby

Upon completion of the freeze, the Auto Program returns the unit to 25°C, the front panel LED display shows auto and the unit remains there until the user initiates the Auto Program again by pressing the SET button.

Page 19

5 Parts and Controls

115V

Front

Foot

Fan

The user should become familiar with the Model 9230 parts. Successful use of the instrument is dependent upon knowledge of important components and theirproperuse.

5.1 Bottom Panel

On the bottom panel are the fan and feet. See Figure 2.

1. The cooling fan inlet is at the bottom of the unit. The cooling air circulating through the instrument keeps the electronics and the chassis cool. Keep the area immediately around the instrument clear to allow adequate ventilation.

2. Three feet support the chassis permitting air space for the fan.

5 Parts and Controls

Bottom Panel

Figure 2 Bottom Panel

Page 20

9230 Maintenance System

SET

ADV

°C/°F

DOWN

UP EXIT

0.020 C

9230

GALLIUM MAINTENANCE APPARATUS 15°C to 30°C

User’s Guide

5.2 Front Panel

The front panel contains the digital display and the controller keypad. See Fig

ure 3.

1. The digital display is an important part of the temperature controller because it not only displays set and actual temperatures but also displays various instru ment functions, settings, and constants. The display shows temperatures in units according to the selected scale °C or °F. When in the Auto Program mode, the display indicates the current status of the unit in the gallium melt process.

2. The four button controller keypad allows easy setting of the set-point tem

perature. The control buttons (SET, DOWN, UP, and EXIT) are used to set the temperature set-point, access and set other operating parameters, and access and set calibration parameters.

Setting the control temperature is done directly in degrees of the current scale and can be set to 0.01 of a degree Celsius or Fahrenheit.

During the Manual mode of operation, the functions of the buttons are as follows:

SET – Used to display the next parameter in the menu and to store parameters to the displayed value.

DOWN – Used to decrement the displayed value of parameters.

UP –Usedtoincrementthedisplayedvalue.

EXIT – Used to exit a function and to skip to the next function. Any changes

made to the displayed value are ignored. Holding the EXIT button for about ½ second returns control to the main display.

Figure 3 Front Panel

Page 21

5.3 Top Panel

Inner Melt Heater Storage Well

Cooling Air Vents

Preheat Wells

Constant Temperature Block Assembly with Gallium Cell

Top Insulation Plugs

SET

ADV

°C/°F

DOWN

UP EXIT

9230

GALLIUM MAINTENANCE APPARATUS 15°C to 30°C

Auto

5 Parts and Controls

Top Panel

The primary feature of the top of the unit is to provide access to the tempera

ture controlled block. The top panel consists of the constant temperature block assembly; two preheat wells, top insulation plug, cooling air vents, the melt heater and melt heater storage well. See Figure 4.

1. The constant temperature block assembly is where the gallium cell is in

serted. Peltier devices surround the cell in order to provide a uniform tempera ture. These devices can be configured by the controller to provide a large vertical gradient during the freezing of the gallium cell, or a very uniform tem perature when maintaining a melting cell.

Figure 4 Top Panel

Page 22

9230 Maintenance System

User’s Guide

2. The inner melt heater is a low-power heater that creates an inner liquid layer next to the reentrant tube of the gallium cell during the melting process. This inner melt heater is controlled automatically by the microprocessor when using the Auto Program mode, or may be used manually with the switch in back. When not in use, the inner melt heater is stored in the well at the back of the unit to prevent it from causing any damage.

3.The thermometer preheat wells are located at the back of the block access well. Thermometers are preheated in these wells prior to insertion into the cell in order to conserve its latent energy.

4. The cooling air vents in the top of the unit permit heated air to exit the unit.

5. The top insulation plugs fit into the well over the gallium cell. See Section

8.5, Inserting the Top Insulation Plugs.

5.4 Rear Panel

The rear panel consists of the power connection, power switch, melt heater switch, inner melt heater connection, and serial port. See Figure 5.

1. The power connection is where the power cord plugs into the back of the instrument.

2. Set the power switch “ON” to operate the instrument and “OFF” to disconnect the power.

3. The melt heater plugs into the rear of the instrument into the inner melt heater connector provided. Be sure it is plugged in during operation.

4. The melt heater switch can be set to MANUAL ON position or AUTO position. The instrument’s microprocessor has control when the switch is in the AUTO position.

Warning: When the melt heater switch is in the MANUAL ON position,

the melt heater is continuously energized and can get hot!

5. The serial port is a DB-9 male connector for interfacing the instrument to a computer or terminal RS-232 communications.

5.5 Thermal Block Assembly

The thermal block assembly holds the gallium cell and heats or cools to main tain the proper temperature. The thermal block assembly consists of the thermal block, thermoelectric Peltier devices, the gallium cell, and the top insulation plugs.

1. The thermal block is specifically designed to contain the gallium cell. The thermal block also has 2 preheat wells for the test thermometers.

Page 23

5 Parts and Controls

RS-232

115V

RS-232

Power Switch

Powe r Connection

RS-232 Interface

MANUAL ON

AUTO

INNER MELT

HEATER

Inner Melt Heater Connector

Melt Heater Switch

Thermal Block Assembly

Figure 5 Rear Panel

Page 24

9230 Maintenance System

User’s Guide

2. The block assembly is heated or cooled as necessary to maintain the proper temperature with thermoelectric Peltier devices.

3. The gallium cell is placed into the block. Use the removal tool to carefully insert or remove the cell.

WARNING: DO NOT use the removal tool to carry the cell.

4. The top insulation plugs are placed over the gallium cell to help maintain the proper temperature. See Section 8.5, Inserting the Top Insulation Plugs.

Page 25

6 Controller Operation

Standby

This section discusses in detail how to operate the instrument temperature con troller using the front control panel. By using the front panel key-switches and LED display, the user may initiate the Auto Program mode; a microproces sor-controlled program that determines set temperatures, scan rates, duration times, Peltier module configurations, and melt heater controls. By controlling all of these parameters in the proper order, a temperature profile can be main tained in the block assembly that assures a uniform melt, maintains the melt over long periods of time, properly refreezes the cell and keeps the cell ready for the next melt cycle. After selecting the Manual mode of operation, the user may monitor the well temperature, adjust the set-point temperature in degrees C or F, monitor the Peltier device output power, adjust the controller propor tional band, and program the operating parameters, program parameters, serial interface configuration, and the controller calibration parameters. Operation of the functions and parameters is shown in the flowchart in Figure 6 on page 22. This chart may be copied for reference.

In the following discussion a button with the word SET, UP, DOWN, or EXIT inside indicates the panel button while the dotted box indicates the display reading. Explanation of the button or display reading are to the right of each button or display value.

When two buttons are shown to initiate an action, for example,

S+D

6.1 Standby

After the instrument is powered ON or at the end of a gallium cell refreeze pro cess, the unit automatically is set to 25°C and the digital LED display reads:

Press and hold the first button (e.g., SET) and then press the second button (e.g., DOWN) and release both

Auto Ready to Start Auto Program

The unit is in a Standby condition and remains at 25°C indefinitely until the user initiates a change by pressing a button sequence.

6.2 Starting the Auto Program

The user begins the Auto Program by pressing the SET button.

Start the Auto Program

uuAlt WAIT - Auto Program started

Page 26

9230 Maintenance System

Powe r ON

Display

“Auto”

T =25°C

SET

Select “nnAn”

Select Set-Point

UP/DN

SET

Adjust Set-Point

Adjust Units °C/°F

Adjust Scan ON/OFF

Display

Temperature

Adjust Scan Rate

UP/DN

Toggles °C/°F

Display Set-Point

Resistance

SET

Adjust Proportional

Band

Configuration

Display Power

Display

“uuAIt”

SET

Display “PREP”

Display “nnaint”

Display “FrEE2H”

Program Advance

SET + DN

PRE-SET TIMEOUT

Display “frEE2C”

Optional

SET+EXIT

SET + UP

SET

EXIT

Adjust

Ready Temperature

SET

Program 1

Parameters

Adjust Prep Melt

Temperature

Adjust Prep

Scan Rate

Adjust

Beeper

Adjust

Prep 1Time

Adjust

Prep 2 Time

Adjust

Prep 3 Time

Adjust Maintain

Temperature

SET

Program 2

Parameters

Adjust Maintain

Time-Out

Adjust Maintain Time-Out Time

Adjust Freeze

Hot Temperature

Adjust Freeze

Hot Time

Adjust Freeze

Cold Temperature

Adjust Freeze

Cold Scan Rate

Adjust Freeze

Melt State

SET

Program 3

Parameters

Adjust

Baud Rate

SET

Serial

Interface

Adjust

Sample Period

Adjust

Duplex Mode

Adjust

Linefeed

Adjust

SET

Cal

Adjust Freeze

Cold Time

EXIT EXIT EXIT EXIT EXIT

Menu Legend: While in MANUAL Mode:

Press the SET button to step through the menu and to access the parameter. Use the UP and DOWN buttons to adjust the parameter value. Press the SET button again to accept and store the new value, and to advance to the next parameter.

Press the EXIT button briefly to skip a parameter without storing the parameter value.

Hold the EXIT button to exit the menu and to display the temperature.

Press the SET and DOWN buttons at the same time to advance the program to AUTO mode.

While in AUTO Mode:

Press the EXIT and UP buttons to momentarily display the block temperature.

The AUTO Mode parameters may be viewed, but no changes are allowed except for the beeper and serial interface parameters.

•

Manual Mode

SET + DOWN

Auto Mode

SET

User’s Guide

(see Figure

Figure 6 Controller Flowchart

Page 27

Plateau

Auto Program – Initiating and Maintaining the Gallium Melt

6 Controller Operation

At this point the Auto Program takes control of the instrument and initiates a melt in the gallium cell in accordance with Figure 1 on page 13 and Figure 6 on page 22.

At any time the user may press the program advance button sequence to access the program advance mode.

S+D

Access program advance

toAuto Exit from auto mode

From here, the set button can be pressed to go back to the Auto state or press the up or down buttons to choose a different program state. Once the desired program state is chosen press SET to accept the chosen state.

The chosen program state will now start.

Accept the program state

6.3 Auto Program – Initiating and Maintaining the Gallium Melt Plateau

Approximately 55-65 minutes after starting the Auto Program, the gallium cell reaches 29.27°C and stabilizes enough to start the melt plateau. The display shows:

prep PrEP – gallium cell melt initiated

The Auto Program takes the block assembly to 30.77°C, which begins melting the outer surface of the gallium inside the cell.

After approximately 8 minutes, the Auto Program energizes the inner melt heater inside the gallium cell entrant well. The instrument sounds an audible beep 4 times and the display message alternates as indicated:

PrEP Alternating message between PrEP and Htr on

Htr on

The inner melt heater is energized for approximately four minutes after which the Auto Program turns it OFF and sounds an audible beep eight times. At this point the display indicates:

PrEP Inner melt heater OFF

The user should remove the inner melt heater at this time. Note: No damage will occur to the gallium cell if the heater is not removed, however, a shorten

Page 28

9230 Maintenance System

User’s Guide

ing of the melt plateau may result. The inner melt heater may be stored in the melt heater well at the back of the unit.

After the inner melt heater has been powered OFF, the instrument remains at

30.77°C for a few more minutes to complete the outer melt of the gallium cell. The unit then sounds an audible beep 16 times, the display changes from PrEP to nnAint and the block temperature is reset to 29.86°C to maintain the melt ing gallium cell.

nnAint Maintain – instrument maintaining melt plateau

6.4 Auto Program – Ending the Gallium Melt Plateau and Refreezing the Cell

At the end of the melt plateau (or when the user wishes to end the plateau), the Auto Program is advanced by pressing the program advance button sequence.

S+D

Display will flash advance for 1 second then show the current program state.

AdU Program advance

nnAint Maintain - instrument maintaining melt plateau

U S

Access program advance

Advances to next program state

Accepts new program state

FrEE2C Start freezing the gallium cell

Gallium, like water, expands in volume when freezing. Therefore, the cell must be frozen from the bottom up or there is a potential for damage to the cell.

The Peltier devices are reconfigured and controlled such that a large tempera ture gradient is generated between the top and bottom of the block. The instru ment slowly scans from 29.86°C to 0°C to maintain the gradient over several hours thus ensuring the cell freezes properly, beginning at the bottom and con tinuing up to the top of the cell.

Page 29

See Section 6.21.2, Maintain Time-out, for optional user defined auto time-out (an optional method of ending the melt plateau and initiating the refreeze pro cess). See Section 6.21.4, Freeze Hot Temperature, for optional user defined freeze hot temperature (a method to totally melt the cell before freezing it).

6.5 Return to Standby

Upon completion of the freeze, the Auto Program returns the unit to 25°C, the digital LED display shows:

Auto Instrument returning to 25°C

6 Controller Operation

Return to Standby

After reaching 25°C, the unit remains there until the user initiates the Auto Pro gram again by pressing the SET button or goes into the Manual mode of operation.

6.6 Program Advance

From the manual mode, the program advance function allows the user to return to the standby condition.

S+D

AdU “ ” flashes and then displays program mode

Auto Program mode

Press the UP or DOWN button to toggle between the Auto Program and Man ual mode.

At any time during the auto program the user may press the program advance button sequence to access the program advance function.

S+D

The current program state will be displayed.

Access program advance

Accepts the new operation

Access program advance

toAuto Return to main menu

PrEP Initiate cell melt with melt heater

nnAint Maintain melt plateau

Page 30

9230 Maintenance System

User’s Guide

FrEE2H Initiate total melt

FrEE2C Start freezing the cell

From the current program state, the up or down buttons can be pressed to choose a different program state.

UorD

Once the desired program state is chosen, press “SET” to accept and start that program.

To get to the wait state the user must select the Auto state then press “set” to start the program in the wait state.

Choose the desired program state

Accept new program state and start the program

6.7 Manual Mode

6.8 Starting the Manual Mode

After the instrument is powered ON or at the end of a gallium cell refreeze process, the unit automatically is set to 25°C and the digital LED display reads:

Auto Ready to start Auto Program

The unit is in a Standby condition and remains at 25°C indefinitely until the user initiates a change by pressing a button sequence. To begin the Manual mode of operation, the user presses the UP or DOWN buttons to change the display reading as follows:

DorU

Toggle display between Auto and Manual

nnAn Ready to go into Manual mode

By pressing the SET button while this is displayed, the instrument goes into the Manual mode and begins to display the well temperature:

25.00C Well temperature in degrees Celsius

Accept Manual mode

Page 31

Once in the Manual mode, the temperature display function may be accessed from any other function by pressing and holding the EXIT button a few seconds.

6.9 Temperature Set-point

6 Controller Operation

Temperature Set-point

The temperature set-point can be set to any value within the range and resolu tion as given in the specifications. Be careful not to exceed the safe temperature limit of any device inserted into the well.

Setting the temperature involves selecting one of the eight (8) set-points in memory and then adjusting the set-point value.

6.9.1 Programmable Set-points

The controller stores eight (8) set-point temperatures in memory. The set-points can be quickly recalled to conveniently set the instrument to a previously pro grammed temperature set-point.

To set the temperature, first select the set-point memory. This function is accessed from the temperature display function by pressing the SET button. The number of the set-point memory currently being used is shown at the left on the display followed by the current set-point value.

25.00C Well temperature in degrees Celsius

Access set-point memory

1 25. Set-point memory 1, 25.0°C currently used

To change the set-point memory to another preset value press the UP or DOWN button.

4 30.C New set-point memory 4, 30.0°C

Press the SET button to display the new selection and access the set-point value.

Display selected set-point memory

29.86 New set-point value 29.86°C

6.9.2 Set-point Value

If the set-point value is correct, hold the EXIT button to accept the new value and resume displaying the well temperature. Otherwise, press the UP or DOWN button to adjust the set-point value.

Page 32

9230 Maintenance System

User’s Guide

22.00 New set-point value

When the desired set-point value is reached press the SET button to accept the new value and to access the temperature scale units. If the EXIT button is pressed, any changes made to the set-point are ignored.

Accept new set-point value

The default programmable set-points (factory set) are given in Table 2.

Tabl e 2 Default Programmable Set-points (Factory Set)

Set-point Memory

Number

1 25.00

2 29.27

3 30.77

4 29.86

5 35.00

6 00.00

7 10.00

8 20.00

NOTE: Setpoint 1 will always be set back to 25.00°C af-

ter the power has been cycled off then on.

Default Set-point Temperature (°C)

6.10 Temperature Scale Units

The temperature scale units of the controller can be set by the user to degrees Celsius (°C) or Fahrenheit (°F). The units are used in displaying the well tem perature, set-point, scan rate, and proportional band.

Press the SET button after adjusting the set-point value to change display units.

Un= C Scale units currently selected

Press the UP or DOWN button to change the units.

Un = F New units selected

The units can also be changed quickly from the main display by pressing the SET and UP buttons.

Page 33

6.11 Scan

The scan rate can be set and enabled so that when the set-point is changed the instrument heats or cools at a specified rate (degrees per minute) until it reaches the new set-point. With the scan disabled the instrument heats or cools at the maximum possible rate.

6.11.1 Scan Control

The scan is controlled with the scan ON/OFF function that appears in the main menu after the set-point and unit’s functions.

ScAn=OFF Scan function OFF

Press the UP or DOWN button to toggle the scan ON or OFF.

ScAn=On Scan function ON

Press the SET button to accept the present setting and continue.

6 Controller Operation

Scan

Accept scan setting

6.12 Scan Rate

The next function in the main menu is the scan rate. The scan rate can be set from 0.1 to 5.0°C/minute (0.2 to 9.0°F/min). The maximum scan rate, however, is actually limited by the natural heating or cooling rate of the instrument. This is typically less than 2°C/minute.

The scan rate function appears in the main menu after the scan control function. The scan rate units are in degrees per minute, degrees C or F depending on the selected units.

Sr= 0.2 Scan rate in °C/min

Press the UP or DOWN button to change the scan rate.

Sr=2.0 New scan rate

Press the SET button to accept the new scan rate and continue.

The display returns to the current well temperature.

Accept scan rate

Page 34

9230 Maintenance System

User’s Guide

6.13 Temperature Scale Units

To toggle between °C and °F, press and hold the SET button and then press the UP button when the temperature is displayed.

6.14 Secondary Menu

Functions used less often are accessed within the secondary menu. Press and hold the SET and EXIT buttons to access the secondary menu. The first func tion in the secondary menu is the power display. (See Figure 6 on page 22.)

6.15 Peltier Device Power

The temperature controller controls the temperature of the well by pulsing the Peltier devices ON and OFF. The total power being applied to the Peltier de vices is determined by the duty cycle or the ratio of device on time to the pulse cycle time. By knowing the amount of heating the user can tell if the instrument is heating up to the set-point, cooling down, or controlling at a constant temperature. Monitoring the percent power lets the user know the stability of the well temperature. With good control stability the percent heating power should not fluctuate more than ±1% within one minute.

The device power display is accessed in the secondary menu. Press and hold the SET and EXIT buttons. The Peltier device power is displayed as a percentage of full power.

25.00 Well temperature

S+E

Access Peltier device power in secondary menu

SEC Flashes and then percent power flashes

Pct Po Flashes prior to displaying Peltier device power

6.0 P Peltier device power in percent

To exit out of the secondary menu press the EXIT button and hold for a brief moment. To continue on to the proportional band setting function, press the EXIT button momentarily or the SET button.

6.16 Set-point Resistance

The set-point resistance is the resistance associated with the set-point tempera ture. Allow the temperature to stabilize at the desired set-point before using the

Page 35

6 Controller Operation

Proportional Band

displayed resistance value. The set-point resistance function is available for di agnostic purposes.

Press the SET and EXIT buttons to enter the secondary menu and show the heater power. Then press the SET button twice to access the set-point resistance.

S+E

Access Peltier device power in secondary menu

SEC Flashes and then percent power flashes

Pct Po Flashes prior to displaying Peltier device power

6.0 Peltier device power in percent

Access set-point resistance

Sr Flashes “ ” (Set-point Resistance) and then displays the

setting

109.715 Resistance in ohms

6.17 Proportional Band

In a proportional controller such as this, the Peltier device output power is proportional to the well temperature over a limited range of temperatures around the set-point. This range of temperature is called the proportional band. At the bottom of the proportional band, the Peltier device output is ±100%. At the top of the proportional band, the Peltier device output is 0. Thus as the temperature rises the Peltier device power is reduced, which consequently tends to lower the temperature back down. In this way the temperature is maintained at a fairly constant value.

The temperature stability of the well and the response time depend on the width of the proportional band. If the band is too wide, the well temperature deviates excessively from the set-point due to varying external conditions. This devia tion is because the power output changes very little with temperature and the controller does not respond well to changing conditions or noise in the system. If the proportional band is too narrow the temperature may swing back and forth because the controller overreacts to temperature variations. For best con trol stability the proportional band must be set for the optimum width.

The proportional band width is set at the factory to about 8.0°C. The propor tional band width may be altered by the user to optimize the control character istics for a particular application.

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The proportional band width is easily adjusted from the front panel. The width may be set to discrete values in degrees C or F depending on the selected units. The proportional band adjustment can be accessed within the secondary menu. Press the SET and EXIT buttons to enter the secondary menu and show the de vice power. Then press the SET button twice to access the proportional band.

S+E

SEC Flashes “ ” and then percent power flashes

Pct Po Flashes prior to displaying Peltier device power

6.0 Peltier device power in percent

Sr Flashes “ ” (Set-point Resistance) and then displays the

109.715 Resistance in ohms

Prop Flashes “ ” and then displays the setting

8.0 Proportional band setting

To change the proportional band press the UP or DOWN button.

Access Peltier device power in secondary menu

Access set-point resistance

setting

Access proportional band

9.0 New proportional band setting

To store the new setting press the SET button. Press the EXIT button to con tinue without storing the new value.

Accept the new proportional band setting

6.18 Controller Configuration, Operating, and Calibration Parameters

The controller has a number of configuration, operating, and calibration param eters that are programmable via the front panel. The first set of parameters is associated with the Auto Program and is located under the configuration submenus called prog 1, prog 2,andprog 3. The next set of parameters is

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Auto Program Configuration Parameters

6 Controller Operation

associated with the serial RS-232 interface and is located under the configura tion submenu called serIAL. The last set of parameters is associated with the calibration of the instrument and is located under the configuration submenu called CAL.

6.19 Auto Program Configuration Parameters

CAUTION: The Auto Program configuration parameters should not be adjusted under normal use. These parameters directly affect the melt pla teau duration time and proper freezing of the gallium cell.

The first set of parameters is associated with the Auto Program (see Figure 1, page 13). The Auto Program is a microprocessor-controlled program that deter mines set temperatures, scan rates, duration times, Peltier module configura tions and melt heater controls. By controlling all of these parameters in the proper order, a temperature profile can be maintained in the block assembly that assures a uniform melt, maintains the melt over long periods of time, properly refreezes the cell and keeps the cell ready for the next melt cycle. The de-

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fault programmable set-points (factory set) are given in Table 3, along with minimum and maximum set values.

Tabl e 3 Auto Program Parameters (Prog 1, Prog 2, Prog 3)

Parameter Name Parameter

Ready Temperature (WAIT)

Prep Melt Temperature (PREP)

Prep Scan Rate (PREP)

Beeper (PREP)

Prep 1 Time (PREP)

Prep 2 Time (PREP)

Prep 3 Time (PREP)

Maintain Temperature (MAINT)

Maintain Time-out (MAINT)

Maintain Time-out Time (MAINT)

Freeze Hot Temperature (FREEZH)

Freeze Hot Time (FREEZH)

Freeze Cold Temperature (FREEZC)

Freeze Cold Scan Rate (FREEZC)

Freeze Cold Time (FREEZC)

Freeze Melt State (Manual Mode Only)

*Factory Set

rdu t

PrEPt

prEPSr

bEEPEr

dur 1

dur 2

dur 3

nnAint

ti out

dur 4

FrEE2H

dur 5

FrEE2C

FrECSr

dur 6

frnELt

Low Value

29.000 29.270 29.300 °C 1 xx.xxx

30.000 30.770 35.000 °C 1 xx.xxx

0.1 0.2 0.5 °C/min 1 x.x

-ON--1ON/OFF

360 480 600 sec 1 xxx

120 240 360 sec 1 xxx

240 360 480 sec 1 xxx

29.790 29.860 35.000 °C 2 xx.xxx

-OFF--2ON/OFF

1 7200 43,200 min 2 xx,xxx

29.860 29.860 36.000 °C 2 xx.xxx

0 0 360 min 2 xxx

-1.000 0.000 10.000 °C 2 xx.xxx

0.4 0.5 0.6 °C/min 2 x.x

120 150 180 min 2 xxx

-MELT--3MELT/

Default Value*

High Value Units Prog Set Resolution

FREEZE

6.20 Prog 1

The parameters within the Prog 1 submenu are accessed from the secondary menu after the proportional band function by pressing the SET button. ConfIg flashes and then the name of the first Auto Program parameter menu ProG 1 is displayed:

8.0 Proportional band setting

ConFIG Flashes before entering configuration menus

Select the configuration menus

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ProG 1 Prog 1 submenu

Pressing the SET button accesses the parameters within the Prog 1 submenu. Pressing the UP button accesses Prog 2. The well temperature is displayed by pressing the EXIT button.

6.20.1 Ready Temperature

The Ready Temperature parameter is the temperature at which the instrument stabilizes before initiating a melt in the gallium cell. The default value is

29.27°C and can be seen on Figure 1 as the temperature that the well goes to when the display shows uuAit. The instrument holds the well at this tempera ture for 30 minutes minimum to assure that the gallium cell has stabilized, be fore allowing the melt to proceed.

When Prog 1 is displayed, press the SET button to access the Ready Tempera ture parameter. The display flashes rdu t and then displays the current Ready Temperature value:

ProG 1 Prog 1 submenu

6 Controller Operation

Prog 1

Access the ready temperature parameter

rdu t Flashes before entering ready temperature

29.270 Current ready temperature

Use the UP or DOWN buttons to adjust the value.

29.300 New ready temperature

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new ready temperature value and continue to Prep Melt Tem perature

6.20.2 Prep Melt Temperature

The Prep Melt Temperature parameter is the temperature at which the instru ment begins to melt the outer surfaces of the gallium within the gallium cell. The default value is 30.77°C and can be seen on Figure 1 as the temperature that the well goes to when the display shows Prep. The instrument holds the well at this temperature for approximately 18 minutes (the sum of Prep 1, Prep 2 and Prep 3 duration times) to begin melting the outer surfaces of the gallium.

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After accessing the Ready Temperature parameter, the display flashes PrEP t and displays the current value of the Prep Melt Temperature.

PrEP t Flashes before entering prep melt temperature parameter

30.770 Current prep melt temperature

Use UP or DOWN buttons to adjust the value.

35.000 New prep melt temperature

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new Prep Melt Temperature value and continue to the Prep Scan Rate

6.20.3 Prep Scan Rate

The Prep Scan Rate parameter is the rate in °C/minute or °F/minute at which the instrument scans from the Ready Temperature to the Prep Melt Temperature. The default value is 0.2°C/minute and can be seen on Figure 1, where the unit begins the melt.

After accessing the Prep Melt Temperature parameter, the display flashes

PrEP sr and displays the current value of the Prep Scan Rate.

PrEP Sr Flashes before entering prep scan rate parameter

Sr = 0.2 Current prep scan rate

Use the UP or DOWN buttons to adjust the value.

Sr = 0.5 New prep scan rate

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

6.20.4 Beeper

The Beeper parameter is used to enable or disable the audible warnings that may be generated during the initiation of the melt. The default value is ON.

Accept new prep scan rate value and continue to the inner melt heater Beeper

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6 Controller Operation

As seen on Figure 1, the Auto Program sounds an audible beep 4 times when it energizes the inner melt heater and the display shows an alternating message from PrEP to Htr on. After approximately 4 minutes, the Auto Program sounds an audible beep 8 times and turns the inner melt heater OFF (the display returns PrEP). After approximately 6 more minutes, the Auto Program sounds an audible beep 16 times and displays nnaint, an indication that the gallium melt has begun.

Changing the Beeper parameter to OFF disables the beeper during this phase of the Auto Program.

After accessing the Prep Scan Rate parameter, the display flashes beeper and displays the current value of the Beeper parameter.

Prog 1

bEEPEr Flashes before entering beeper parameter

On Current beeper setting (enabled)

Use the UP or DOWN buttons to adjust the value.

OFF New beeper setting

If no changes are desired, press the EXIT button to continue to the next parameter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new beeper setting and continue to the prep 1 time

6.20.5 Prep 1 Time

After beginning the gallium melt, see Figure 1, the Auto Program waits a short time before energizing the inner melt heater. The Prep 1 Time parameter speci fies this time in seconds. The default value is 480 seconds (8 minutes). At the end of this time, the Auto Program energizes the inner melt heater and sounds 4 audible beeps.

After accessing the Beeper parameter, the display flashes dur 1 and displays the current value of the Prep 1 Time parameter.

dur 1 Flashes before entering the prep 1 time parameter

SEC480 Current prep 1 time value (8 minutes)

Use the UP or DOWN buttons to adjust the value.

SEC600 New prep 1 time value (10 minutes)

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If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new prep 1 time value and continue to prep 2 time

6.20.6 Prep 2 Time

After energizing the inner melt heater during the initialization of the gallium melt, see Figure 1, the Auto Program waits a short time before turning OFF the inner melt heater. The Prep 2 Time parameter specifies this time in seconds. The default value is 240 seconds (4 minutes). At the end of this time, the Auto Program turns the inner melt heater OFF and sounds 8 audible beeps.

After accessing the Prep 1 Time parameter, the display flashes dur 2 and dis plays the current value of the Prep 2 Time parameter.

dur 2 Flashes before entering the prep 2 time parameter

SEC240 Current prep 2 time value (4 minutes)

Use the UP or DOWN buttons to adjust the value.

SEC360 New prep 2 time value (6 minutes)

If no changes are desired, press the EXIT button to continue to the next parameter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new prep 2 time value and continue to prep 3 time

6.20.7 Prep 3 Time

After turning OFF the inner melt heater during the initialization of the gallium melt, see Figure 1, the Auto Program waits a short time before beginning the maintenance process of the gallium melt plateau. During this time the instru ment remains at 30.77°C to complete the melting of the outer surfaces of the gallium in the cell. The Prep 3 Time parameter specifies this time in seconds. The default value is 360 seconds (6 minutes). At the end of this time, the Auto Program begins the maintenance process and sounds 16 audible beeps.

After accessing the Prep 2 Time parameter, the display flashes dur 3 and dis plays the current value of the Prep 3 Time parameter.

dur 3 Flashes before entering the prep 3 time parameter

SEC360 Current prep 3 time value (6 minutes)

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Use the UP or DOWN buttons to adjust the value.

SEC480 New prep 3 time value (8 minutes)

6 Controller Operation

Prog 2

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and to return to the Prog 1 submenu.

ProG 1 Prog 1 submenu

Press the UP button to access Prog 2. The well temperature is displayed by pressing the EXIT button. Press the SET button to access the parameters within the Prog 1 submenu.

6.21 Prog 2

Prog 2 is displayed by pressing the UP button while the display shows ProG 1 . Pressing the SET button then accesses the parameters within the Prog 2

submenu.

ProG 1 Prog 1 submenu

ProG 2 Prog 2 submenu

Pressing the DOWN button may access Prog 1. Pressing the UP button may ac cess Prog 3. The well temperature is displayed by pressing the EXIT button. Pressing the SET button accesses the parameters within the Prog 2 submenu.

Accept new prep 3 time value and return to the prog 1 submenu

Select the Prog 2 submenu

6.21.1 Maintain Temperature

The Maintain Temperature parameter is the temperature at which the instru ment stabilizes and remains during the melt plateau in the gallium cell. The de fault value is 29.86°C and can be seen on Figure 1 as the temperature that the well goes to when the display shows nnAint. The instrument holds the well at this temperature until the melt plateau is ended.

ProG 2 Prog 2 submenu

Access the maintain temperature parameter

nnaint Flashes before entering the maintain temperature

parameter

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29.860 Current maintain temperature value

Use the UP or DOWN buttons to adjust the value.

29.790 New maintain temperature value

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new maintain temperature value and continue to the main tain time-out

6.21.2 Maintain Time-out

The Maintain Time-out setting is used to enable a preset delay time after which the gallium melt plateau is terminated. The default setting is OFF and at this setting the instrument remains at the Maintain Temperature until the user ad vances the Auto Program by depressing the SET and DOWN buttons and then selecting the FrEE2C program state. A refreeze of the gallium cell is then started.

If the Maintain Time-out setting is ON, the Auto Program automatically ends the gallium melt plateau after the preset delay time has been reached and refreezes the gallium cell. It can be seen on Figure 1 under the Maintain portion of the Auto Program.

After accessing the Maintain Temperature parameter, the display flashes ti

out and displays

ti out Flashes before entering the maintain time-out parameter

OFF Current maintain time-out setting

Use UP or DOWN buttons to adjust the value.

On New maintain time-out setting

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new maintain time-out setting and continue to the maintain time-out time

6.21.3 Maintain Time-out Time

The Maintain Time-out Time parameter is the time that the instrument main tains the gallium cell at the Maintain Temperature before terminating the gal

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6 Controller Operation

lium melt plateau. The default value is 7200 minutes (5 days). It is only used if the Maintain Time-out parameter is set to ON. If the Time-out parameter is set to ON, the instrument ends the Maintain portion of the Auto Program after the Maintain Time-out Time has been reached and refreezes the gallium cell. It can be seen on Figure 1 under the Maintain portion of the Auto Program.

After accessing the Maintain Time-out parameter, the display flashes dur 4 and displays the current value of the Maintain Time-out Time.

Prog 2

dur 4 Flashes before maintain time-out time parameter

7200 Current maintain time-out time value (7200 minutes)

Use the UP or DOWN buttons to adjust the value.

1440 New maintain time-out time value (1440 minutes)

If no changes are desired, press the EXIT button to continue to the next parameter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new maintain time-out time value and continue to the freeze hot temperature

6.21.4 Freeze Hot Temperature

After the melt plateau is finished or the user has ended the melt, the instrument normally proceeds to refreeze the cell. If desired, the Freeze Hot Temperature and Freeze Hot Time parameters may be used to preset the instrument to totally melt the cell before refreezing.

The Freeze Hot Temperature parameter is the temperature at which the instru ment totally melts the gallium in the cell. The value can be set up to 36.00°C and can be seen on Figure 1 as the temperature that the well goes to when the display shows FrEE2H. The instrument holds the well at this temperature for up to 6.0 hours to ensure that all of the gallium has been melted before refreezing the cell.

After accessing the Maintain Time-out Time parameter, the display flashes

FrEE2H and displays the current value of the Freeze Hot Temperature.

FrEE2H Flashes before entering the freeze hot temperature

parameter

29.86 Current freeze hot temperature value

Use the UP or DOWN buttons to adjust the value.

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36.00 New freeze hot temperature value

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new freeze hot temperature value and continue to the freeze hot time

6.21.5 Freeze Hot Time

The Freeze Hot Time parameter is the time that the instrument maintains the gallium cell at the Freeze Hot Temperature to totally melt the gallium in the cell. The value can be set up to 360 minutes (6 hours) and can be seen on Fig ure 1 as the time duration when the display shows FrEEZH. The instrument re mains at the Freeze Hot Temperature for this time to ensure that all of the gallium has been melted before refreezing the cell.

Note: The default program does not use the Freeze Hot option and thus the Freeze Hot time is set to 0 seconds.

After accessing the Freeze Hot Temperature parameter, the display flashes dur

5 and displays the current value of the Freeze Hot Time.

dur 5 Flashes before entering the freeze hot time parameter

0 Current freeze hot time value (0 minutes)

Use the UP or DOWN buttons to adjust the value.

360 New freeze hot time value (360 minutes)

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new freeze hot time value and continue to the freeze cold temperature

6.21.6 Freeze Cold Temperature

The Freeze Cold Temperature parameter is the temperature to which the instru ment scans during the refreezing of the gallium cell. The default value is

0.00°C and can be seen on Figure 1 as the temperature the unit scans to while the display shows FrEE2C.

After accessing the Freeze Hot Time parameter, the display flashes Free2C and displays the current value of the Freeze Cold Temperature.

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6 Controller Operation

FrEE2C Flashes before entering the freeze cold temperature

parameter

0.000 Current freeze cold temperature value

Use the UP or DOWN buttons to adjust the value.

5.000 New freeze cold temperature value

Prog 2

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new freeze cold temperature value and continue to the freeze cold scan rate

6.21.7 Freeze Cold Scan Rate

The Freeze Cold Scan Rate parameter is the rate in °C/minute or °F/minute at which the instrument scans from the Freeze Hot Temperature to the Freeze Cold Temperature. The default value is 0.5°C/minute and can be seen on Figure 1 where the unit begins to refreeze the gallium cell. This parameter is very important for the proper gradient to be maintained during the refreeze process.

After accessing the Freeze Cold Temperature parameter, the display flashes

frECsr and displays the current value of the Freeze Cold Scan Rate.

FrECSr Flashes before entering the freeze cold scan rate parameter

Sr = 0.5 Current freeze cold scan rate

Use the UP or DOWN buttons to adjust the value.

Sr = 0.6 New freeze cold scan rate

If no changes are desired, press the EXIT button to continue to the next param eter. Press the SET button to accept the new value and continue on to the next parameter.

Accept new freeze cold scan rate value and continue to the Freeze Cold Time

6.21.8 Freeze Cold Time

The Freeze Cold Time parameter is the time that the instrument scans to and maintains the gallium cell at the Freeze Cold Temperature to totally refreeze the gallium in the cell. The default value is 150 minutes (2.5 hours). At the end of

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this time, the Auto Program returns the well to 25°C to wait for the next melt process.

After accessing the Freeze Cold Scan Rate parameter, the display flashes dur

6 and displays the current value of the Freeze Cold Time parameter.

dur 6 Flashes before entering the freeze cold time parameter

150 Current freeze cold time value (150 minutes)

Use the UP or DOWN buttons to adjust the value.

180 New freeze cold time value (180 minutes)

If no changes are desired, press the EXIT button to Prog 1 submenu. Press the SET button to accept the new value and continue on to the next parameter.

Prog 1 may be accessed by pressing the DOWN button. Prog 3 may be accessed by pressing the UP button. The well temperature is displayed by pressing the EXIT button. Pressing the SET button accesses the parameters within the Prog 2 submenu.

Accept new freeze cold time value and continue to the Prog 2 submenu

6.22 Prog 3

Prog 3 is displayed by pressing the UP button while the display shows ProG

2. Pressing the SET button then accesses the parameters within the Prog 3

submenu.

ProG 2 Prog 2 submenu

ProG 3 Prog 3 submenu

Prog 2 may be accessed by pressing the DOWN button. The serial interface menu may be accessed by pressing the UP button. The well temperature is dis played by pressing the EXIT button. Pressing the SET button accesses the pa rameters within the Prog 3 submenu.

6.22.1 Freeze Melt State

Select the Prog 3 submenu

The Freeze Melt State parameter is used to control the configuration of the Peltier devices and is only usable in the manual mode of operation. During nor mal operation of the instrument this parameter should not be altered.

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6 Controller Operation

Serial Interface Parameters

During the melt and maintain processes, the Peltier devices are configured to apply a uniform heat source to the well. This minimizes vertical gradients in the well and gallium cell to maximize the length of the melt plateau. During a Freeze process, the Peltier devices are configured to generate a large vertical gradient in the well to ensure the proper refreezing of the gallium cell.

The default setting for this parameter is MELT.

The Freeze Melt State parameter is accessed from the Prog 3 submenu.

ProG 3 Prog 3 submenu

Access the Freeze Melt State parameter

FrnELT Flashes before entering the freeze melt state parameter

nnELT Current freeze melt state setting

Use the UP or DOWN buttons to adjust the setting.

FrEE2E New freeze melt state setting

If no changes are desired, press the EXIT button to exit the Prog 3 submenu. Press the SET button to accept the new value and return to the Prog 3 submenu.

The display then shows ProG 3 and returns to the Prog 3 submenu.

Accept new Freeze Melt State setting

ProG 3 Prog 3 submenu

6.23 Serial Interface Parameters

The serial RS-232 interface parameters menu is indicated by,

SEriAL Serial RS-232 interface parameters menu

The serial interface parameters menu contains parameters, which determine the operation of the serial interface. The parameters in the menu are – BAUD rate, sample period, duplex mode, and linefeed.

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6.23.1 BAUD Rate

The BAUD rate is the first parameter in the menu. The BAUD rate setting de termines the serial communications transmission rate. The BAUD rate of the serial communications may be programmed to 300, 600, 1200, 2400, 4800, or

9600. The default setting is 2400 baud.

bAUd Flashes before displaying the serial baud rate setting

2400 b Current BAUD rate

Use the UP or DOWN buttons to adjust the setting.

1200 b New BAUD rate

Press the SET button to store the new setting as the baud rate or press the EXIT button briefly to skip to the next parameter without storing the new setting.

6.23.2 Sample Period

The sample period is the next parameter in the serial interface parameter menu. The sample period is the time period in seconds between temperature measurements transmitted from the serial interface. If the sample rate is set to 5, the instrument transmits the current measurement over the serial interface approximately every five seconds. The automatic sampling is disabled with a sample period of 0.

SPer Flashes before displaying serial sample period setting

SP=1 Current sample period (seconds)

Use the UP or DOWN buttons to adjust the setting.

SP=60 New sample period

Press the SET button to store the new setting as the sample period or press the EXIT button briefly to skip to the next parameter without storing the new setting.

6.23.3 Duplex Mode

The next parameter is the duplex mode. The duplex mode may be set to full du plex or half duplex. With full duplex any commands received by the instrument via the serial interface are immediately echoed or transmitted back to the device of origin. With half duplex the commands are executed but not echoed.

dUPL Flashes before displaying serial duplex mode setting

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d=FULL Current duplex mode

Use the UP or DOWN buttons to adjust the setting.

d=HALF New duplex mode setting

Press the SET button to store the new setting as the duplex mode or press the EXIT button briefly to skip to the next parameter without storing the new setting.

6.23.4 Linefeed

6 Controller Operation

Calibration Parameters

The final parameter in the serial interface menu is the linefeed mode. This pa rameter enables (on) or disables (off) transmission of a linefeed character (LF, ASCII 10) after transmission of any carriage-return.

LF Flashes before displaying serial linefeed setting

LF=On Current linefeed setting

Use the UP or DOWN buttons to adjust the setting.

LF=OFF New linefeed setting

Press the SET button to store the new setting as the linefeed.

Prog 3 may be accessed by pressing the DOWN button. The calibration menu may be accessed by pressing the UP button. The well temperature is displayed by pressing the EXIT button. Pressing the SET button accesses the parameters within the serial interface menu.

6.24 Calibration Parameters

The operator of the instrument has access to one of the calibration constants, R0. This value is set at the factory and must not be altered. The correct value is important to the accuracy and proper and safe operation of the instrument. This parameter should not be adjusted except in the event the controller’s memory fails. The user may then restore this value to the factory setting. This constant is supplied to the user on the Report of Calibration with the manual.

CAUTION: DO NOT change the value of the instrument calibration con stant from the factory set value. The correct setting of this parameter is important to the safety and proper operation of the instrument.

CAL Calibration parameters menu

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Press the SET button five times to enter the menu.

6.24.1 R0

The calibration parameter R0 characterizes the resistance temperature relation ship of the platinum control sensor. This parameter may be adjusted by an ex perienced user to improve the accuracy of the instrument.

To properly maintain the gallium cell during the melt plateau and during the refreezing process, the accuracy of the Model 9230 near the gallium melting point (29.7646°C) must be very precise, ±0.05°C or better. The value of R0 for this instrument refers to the resistance of the control probe at 0°C. For calibra tion purposes, the value of R0 is adjusted to compensate for the error at

29.27°C. The value of this parameter is set at the factory for best instrument ac curacy. This parameter may be adjusted by an experienced user to improve the accuracy of the instrument (see Section 10, Calibration Procedure).

From the CAL submenu, pressing the SET button 5 times accesses the R0 parameter:

CAL Calibration parameters menu

Press the SET button five times to enter the menu.

r0 Flashes before displaying the R0 setting

99.788 Current R0 value (ohms)

Use the UP or DOWN button to adjust the setting.

99.999 New R0 value (ohms)

If no changes are desired, press the EXIT button to return to the CAL submenu. Press the SET button to accept the new value.

The display then shows CAL and returns to the CAL submenu. The serial inter face menu may be accessed by pressing the DOWN button. The well tempera ture is displayed by pressing the EXIT button. Pressing the SET button five times accesses the R0 parameter within the CAL submenu.

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7 Digital Communication Interface

The Model 9230 is capable of communicating with and being controlled by other equipment through the digital interface.

With a digital interface the instrument may be connected to a computer or other equipment. This allows the user to set the set-point temperature, monitor the temperature, and access any of the other controller functions, all using remote communications equipment. Communications commands are summarized in Table 4 on page 52.

7.1 Serial Communications

The instrument is installed with an RS-232 serial interface that allows serial digital communications over fairly long distances. With the serial interface the user may access any of the functions, parameters and settings discussed in Sec tion 7, Controller Operation with the exception of the BAUD rate setting. Addi tionally, when the instrument is in Standby mode (well at 25°C and display shows Auto), the user is required to use the front panel buttons, to enter Manual mode or to initiate the Auto Program.

The serial interface operates with eight data bits, one stop bit, and no parity.

Serial Communications

7.1.1 Wiring

The serial communications cable attaches to the instrument through the DB-9 connector at the back of the instrument. Figure 7 shows the pin-out of this connector and suggested cable wiring. To eliminate noise, the serial cable should be shielded with low resistance between the connector (DB-9) and the shield. If the instrument is used in a heavy industrial setting, the serial cable must be limited to one meter in length.

7.1.2 Setup

Before operation, the serial in terface must first be set up by programming the BAUD rate and other configuration parame ters. These parameters are pro

Figure 7 Serial Cable Wiring

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grammed within the serial interface menu.

To enter the serial interface menu from the standby mode do the following:

Auto Instrument in standby mode

Use the UP or DOWN buttons to select the manual mode.

nnAn Instrument in manual mode

25.00 C Well temperature displayed

S+E

Pct Po Flashes prior to displaying Peltier device power

18.0 P Peltier device power in percent

ConFIG Flashes configuration menu

ProG 1 Program 1 submenu

SErIAL Serial interface menu

Enter the manual mode

Enter the secondary menu

SEC Flashes and then

Continue pressing the SET button until the display shows

Press the UP button three times until is displayed

7.1.2.1 Baud Rate

The baud rate is the first parameter in the menu. The display prompts with the baud rate parameter by showing “bAUd”. Press the SET button to choose to set the baud rate. The current baud rate value is displayed. The baud rate may be programmed to 300, 600, 1200, or 2400 baud. The baud rate defaults to 2400 baud.

Access the serial interface parameters

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Use the UP or DOWN buttons to change the baud rate value. Press the SET button to set the baud to the new value or the EXIT button to abort the opera tion and skip to the next parameter in the menu.

7.1.2.2 Sample Period

The sample period is the next parameter in the menu and prompted with “SPEr”. The sample period is the time period, in seconds, between tempera ture measurements transmitted from the serial interface. If the sample rate is set to 5, the instrument transmits the current measurement over the serial interface approximately every five seconds. The automatic sampling is disabled with a sample period of 0. Press the SET button to choose to set the sample period. Adjust the period with the UP or DOWN button and then use the SET to set the sample rate to the displayed value.

7.1.2.3 Duplex Mode

The next parameter is the duplex mode indicated with “dUPL”. The duplex mode may be set to half duplex (“HALF”) or full duplex (“FULL”). With full duplex any commands received by the instrument via the serial interface are immediately echoed or transmitted back to the device of origin. With half duplex the commands are executed but not echoed. The default setting is full duplex. The mode may be changed using the UP or DOWN buttons and pressing the SET button.

7 Digital Communication Interface

Interface Commands

7.1.2.4 Linefeed

The final parameter in the serial interface menu is the linefeed mode. This parameter enables (“On”) or disables (“OFF”) transmission of a linefeed charac- ter (LF, ASCII 10) after transmission of any carriage-return. The default setting is with linefeed on. The mode may be changed using the UP or DOWN buttons and pressing the SET button.

7.1.3 Serial Operation

Once the cable has been attached and the interface set up properly the control ler immediately begins transmitting temperature readings at the programmed rate. The set-point and other commands may be sent to the instrument via the serial interface to set the temperature set-point and to view or program the vari ous parameters. The interface commands are discussed in Section 8.3, Interface Commands.

The serial interface operates with eight data bits, one stop bit, and no parity.

7.2 Interface Commands

The various commands for accessing the instrument functions via the digital in terface are listed in this section. These commands are used with the RS-232 se rial interface. The commands are terminated with a carriage-return character. The interface makes no distinction between upper and lower case letters, hence

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9230 Maintenance System

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either may be used. Commands may be abbreviated to the minimum number of letters, which determines a unique command. A command may be used to ei ther set a parameter or display a parameter depending on whether or not a value is sent with the command following an “=” character. For example, an “s”<cr> returns the current set-point and an “s=28.00”<cr> sets the set-point to 28.00 degrees.

In the following list of commands, characters or data within brackets, “[“ and “]”, are optional. A slash, “/”, denotes alternate characters or data. Numeric data, denoted by “n”, may be entered in decimal or exponential notation. Char acters are shown in lower case although upper case may be used. Spaces may be added within command strings and are simply ignored. Backspace (BS, ASCII 8) may be used to erase the previous character. A terminating CR is im plied with all commands.

Tabl e 4 Serial Interface Commands

Command Description Command Format

Display Temperature

Read current set-point s[etpoint] s set: 9999.99{C or F} set: 25.00 C

Set current set-point to n s[etpoint]=n s=28 -5.00C to

Read units u u u:{C or F} u: C

Read temperature t t t: 9999.99{C or F} t: 29.86 C

Set temperature units: u[nits]=c/f CorF

Set temperature units to Celsius u[nits]=c u=c

Set temperature units to

Fahrenheit

Read scan function sc[an] sc scan:{ON or OFF} scan:ON

Set scan function: sc[an]=on/of[f] ON or OFF

Turn scan function on sc[an]=on sc=on

Turn scan function off sc[an]=of[f] sc=of

Read scan rate sr[ate] sr srat: 999.99{C or F}/min srat: 0.5C/min 0.1C/min to

Setscanrateto minute

Read program state adv adv adv:{OFF, WAIT, PREP,

Advance program state adv={adv/auto} adv=adv ADV, AUTO

Secondary Menu

Read heater power (duty cycle)

degrees per

u[nits]=f u=f

sr[ate]=n]sr=5

po[wer] po po: 999.9 po: 12.3

Command Example Returned

MAINTAIN, FREEZHOT, FREEZCOLD}

Returned Example

WAIT

Acceptable Values

40.00C

5.0C/min

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7 Digital Communication Interface

Interface Commands

Command Description Command Format

Read proportional band pr[op-band] pr pb: 999.9 pb: 8

Set proportional band pr[op-band]=n pr=8.83 0.1C to 100C

Read set-point resistance *sr *sr 999.999 111.153

Configuration Menu

Program 1

Read ready temp rd[y] rd readytemp :99.99(C orF)readytemp:29.2

Set ready temp rd[y]=n rd=29.27 28.0 to 29.30 C

Read prep melt temperature me me Preptemp:999.99(C orF)Preptemp:30.77

Set prep melt temperature me=n me=30.77 30.0 to 35.0 C

Read prep scan rate ps[ra] ps Prepsrate :99.9(C or

Set prep scan rate ps[ra]=n ps=0.2 0.1 to 0.5 C/min

Read beeper setting bee[p] bee beep: ON/OFF beep: ON

Set beeper bee[p]=on/of[f] bee=off ON or OFF

Read prep 1 duration prea prea Prep1dur :999 sec Prep1dur :360

Set prep 1 duration prea=n prea=400 360 to 600 sec

Read prep 2 duration preb preb Prep2dur :999 sec Prep2dur :360

Set prep 2 duration preb=n preb=300 120 to 360 sec

Read prep 3 duration prec prec Prep3dur :999 sec Prep3dur :360

Set prep 3 duration prec=n prec=400 240 to 480 sec

Program 2

Read maintain temperature ma ma ma:99.999{C or F} ma:29.86 C

Set maintain temperature ma=n ma=29.86 29.79 to 35.00

Read maintain duration dm dm dm:99999 dm:7200

Set maintain duration dm=n/OFF dm=1000 OFF,1 to 43200

Read freeze hot temperature freh freh freezHtemp:99.99(C orF)freezHtemp:99.

Set freeze hot temperature freh=n freh=35.00 29.86 to 36.00

Read freeze hot duration dfrh dfrh freezHdur : 999 min freezHdur : 150

Set freeze hot duration dfrh=n dfrh=300 0 to 360 min

Read freeze cold temperature fr[ec] fr freezCtemp :99.99(C orF)freezCtemp

Command Example Returned

F)/min

Returned Example

Prepsrate:0.2 C/min

Sec

99(C or F)

:99.99(C or F)

Acceptable Values

min

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Command Description Command Format

Set freeze cold temperature fr[ec]=n fr=0.01 -0.01 to 10.00 C

Read freeze cold scan rate fc[sr] fc freezCsrate: 0.2(C or

Set freeze cold scan rate fc[sr]=n fc=0.6 0.4 to 0.6 C/min

Read freeze cold duration d[frc] dfrc freezCdur : 140 min freezCdur : 140

Set freeze cold duration d[frc]=n df=170 120 to 180 min

Program 3

Read freeze/melt state frm[t] frm FreezeMelt: MELT Mode FreezeMelt:

Set freeze/melt state frm[t]=n frm=melt MELT or

Serial Interface Menu

Read serial sample setting sa[mple] sa sa: 9 sa: 1

Set serial sampling setting to seconds

Set serial duplex mode: du[plex]=f[ull]/h[alf] FULL or HALF

Set serial duplex mode to full du[plex]=f[ull] du=f

Set serial duplex mode to half du[plex]=h[alf] du=h

Set serial linefeed mode: lf[eed]=on/of[f] ON or OFF

Set serial linefeed mode to on lf[eed]=on lf=on

Set serial linefeed mode to off lf[eed]=of[f] lf=of

Calibration Menu

Read R0 calibration parameter r[0] r r0: 999.999

Set R0 calibration parameter r[0]=

These commands are only used for factory testing

Miscellaneous (not on menus)

Read firmware version number *ver[sion] *ver ver: 999,9.99 ver.9230,v1.00

Read structure of all commands h[elp] h list of commands

Legend: [] Optional Command data

NOTE:

sa[mple]=

{} Returns either information n Numeric data supplied by user 9 Numeric data returned to user x Character data returned to user

When DUPLEX is set to FULL and a command is sent to READ, the command is returned followed by a carriage return and linefeed. Then the value is returned as indicated in the RETURNED column.

Command Example Returned

F)/min

sa=0 0 to 10,000

r=100.713 98.0 to 102.0

Returned Example

freezCsrate:

0.2(C or F)/min

MELT Mode

Acceptable Values

FREEZE

ohms

Page 59

8 Melting Point of Gallium Realization

This section explains the procedure for realizing the melting point of gallium using a Model 5943 Stainless Steel Gallium Cell and the Model 9230 Mainte nance System.

8.1 General

The gallium melting point (29.7646°C) is a critical temperature. Thermometers used in life science, environmental monitoring, at room or body temperatures, and many other applications depend on it for accurate calibrations. Laboratory standards rely on it as an ITS-90 check standard and as a means of measuring drift between calibrations. Use of the Model 5943 Stainless Steel Gallium Cell and the Model 9230 Maintenance System provides an easy way to generate and maintain the gallium melting point. Plateaus lasting up to 5 days are typical.

The Model 5943 Stainless Steel Gallium Cell holds a gallium sample that is

99.99999+% pure. The gallium is sealed in a Teflon envelope in a high purity argon atmosphere, which is then sealed inside a stainless steel housing. This double-sealing method reduces leaching of the gallium sample and ensures a life of ten years or longer for the cell. Gallium expands on freezing by 3.1% and, to compensate for this, the inner construction of the cell incorporates a flexible Teflon wall. Although the cell is more rugged than other gallium cells, care must be taken to prevent damage to the cell, particularly during the refreeze process. Because gallium expands on freezing (like water), the cell must be frozen from the bottom up or there is potential for damage to the cell. The Auto Program process of the Model 9230 ensures that the cell is frozen properly. The cell’s entrant well dimensions are 8.7” (length) x 0.324” (diameter) with an immersion depth of 6.58” in gallium.

The Model 9230 Gallium Maintenance Apparatus is specifically designed to maintain the Model 5943 Gallium Cell. Once properly installed in the Model 9230, the Auto Program may be started and subsequently initiates the melt pla teau, maintains the plateau for up to 5 days typical, and properly refreezes the cell for the next melt. When not actively melting or refreezing a cell, the Model 9230 automatically maintains the cell at 25.00°C (Standby), well below the melting point. To initiate a melt, the inner melt heater is inserted into the cell and the Auto Program is started through the Model 9230’s front-panel buttons. The Model 9230 increases its temperature to just above the gallium point and powers the 8-watt inner melt heater. Approximately 30 minutes later, the gal lium cell is ready to be used (see Figure 1).

The Model 9230 uses a Proportional Integral Derivative PID controller with specialized analog circuitry to control several Peltier devices. The controlled Peltier devices provide the appropriate amount of heating or cooling to the block assembly into which the gallium cell is inserted. The controller also con trols the inner melt heater, cooling fan and beeper alarm. Two preheat wells en sure that thermometers are properly warmed when inserted into the gallium cell. The preheat wells are oversized so thermometers fit loosely and heat loss

General

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9230 Maintenance System

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from the gallium cell is neither too sudden nor too severe when cold thermome ters are initially placed into the wells.

At the end of the melting plateau (or when the user wishes to end the plateau), the Auto Program is advanced. When totally melted, the Peltier devices are re configured and controlled such that a large temperature gradient is generated between the top and bottom of the block. The instrument slowly scans to 0°C to maintain the gradient over several hours. This ensures that the gallium cell is frozen from the bottom up.

In summary, the following steps are involved in the realization of the melting point of gallium:

Prepare the Model 9230 to receive the gallium cell.

•

Prepare the frozen Model 5943 gallium cell to be installed in the Model

•

9230.

Install the frozen Model 5943 Stainless Steel Gallium Cell into the Model

•

9230.

• Insert the top insulation plugs into the well on top of the cell.

• Insert the inner melt heater into the entrant well of the gallium cell.

• Start the Auto Program.

• Generate the melt plateau and remove the inner melt heater when

prompted by the Model 9230 beeper alarm.

• Calibrate thermometers during the gallium melt plateau.

• Advance the Auto Program to refreeze the cell.

The details of operating the Model 9230 to realize the melting point of gallium are explained for each step in the following sections.

8.2 Preparing the Model 9230 to Receive the Gallium Cell

The Model 9230 is designed to be used in a controlled laboratory environment (see Section 3.2, Environmental Conditions). Control the ambient temperature to a fixed temperature within the specified operating range (18°C to 28°C). Rapid changes in ambient temperature of more than ±1.0°C reduces the stabil ity of the instrument. Avoid drafty areas.

Place the Model 9230 on a flat surface with at least 6 inches of free space around and 18 inches above the instrument.

Make sure that the well of the instrument is clean and clear of any foreign ob jects, debris, dirt or grit.

Connect the inner melt heater to the back of the instrument making sure that it is securely connected. Place the inner melt heater cartridge into the melt heater storage well at the top back of the instrument.

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Installation in the Model 9230

Preparing the Frozen Model 5943 Gallium Cell for

8 Melting Point of Gallium Realization

Verify that the POWER switch is in the OFF position (“0”). Verify that the In ner Melt Heater switch is in the AUTO position. Install the power cord into the power entry module on the back of the instrument and plug the cord into a mains outlet of the proper voltage, frequency, and current capability. Turn on the power to the instrument by toggling the switch on the power entry module located on the back of the instrument. The fan should begin blowing air through the instrument, the beeper sounds one beep, and the display illuminates after approximately 3 seconds. After a brief self-test the controller should begin normal operation, the instrument will begin to approach 25°C, and the display will show Auto.

8.3 Preparing the Frozen Model 5943 Gallium Cell for Installation in the Model 9230

Maintain the Model 5943 gallium cell at temperatures below the melting point (29.7646°C). The cell must be frozen when installed in the Model 9230.

Make sure that the outer surfaces and entrant well of the frozen Model 5943 gallium cell are clean and that the entrant well of the cell is clear of any foreign objects, debris, dirt or grit. Use pure or reagent grade alcohol and clean, soft cotton cloths to clean all surfaces if necessary. Thoroughly dry the cell before continuing.

Add a small amount of silicone oil 200.05, or equivalent transfer fluid, to the entrant well of the cell. Do not overfill the entrant well. The oil level in the well should be approximately the same level (52 mm below the top of the cell) as that of the gallium in the cell when the thermometer is in place in the well.

8.4 Installing the Frozen Model 5943 Gallium Cell into the Model 9230

The instrument comes with a cell removal tool to aid in installing and removing the gallium cell from the Model 9230 well. The tool has a spring-loaded handle with a compressible rubber tip. When the handle is squeezed, thereby com pressing the spring, the rubber tip is extended and the tip may be inserted into the entrant well of the cell. Releasing the handle causes the rubber tip to com press and become firmly positioned in the entrant well. Once lodged in the en trant well, the cell can be gently lowered into the Model 9230 well. Wet the rubber tip of the tool with transfer fluid (e.g. silicone oil 200.05) for ease in in serting into the cell’s entrant well.

CAUTION: Do not use the cell removal tool to carry the cell. The tool is to be used only to aid in installing and removing the cell from the Model 9230 well. Do not drop the cell into the well. Damage to the cell and Model 9230 may occur if the cell is dropped.

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With one hand holding the outside of the cell, insert the cell removal tool tip into the cell’s entrant well as described above and verify that the rubber tip is firmly lodged after releasing the tool handle. Hold onto the removal tool with the other hand and gently lower the cell with the tool the rest of the way while carefully releasing the grip on the outside of the cell. When the cell is securely lowered into the Model 9230 well, compress the removal tool handle to loosen the rubber tip and gently remove the tool from the cell’s entrant well. The gal lium cell is now installed in the Model 9230.

8.5 Inserting the Top Insulation Plugs

The instrument comes with 4 rubber insulation plugs to be inserted into the Model 9230 well on top of the cell (2 spares). The plugs have a hole in the cen ter through which thermometers can be inserted. The plugs serve two purposes. First, they help ensure an even temperature profile in the block and cell allow ing a longer lasting and more accurate melting-point realization. Second, they protect against excessive moisture condensation during the cell refreezing pro cess. Condensation can lead to corrosion over the long term and freezing water can damage the block.

Firmly insert two insulation plugs into the Model 9230 well on top of the cell. Make sure that they are positioned such that the center holes are aligned with the entrant well of the gallium cell.

8.6 Inserting the Inner Melt Heater

The inner melt heater’s function is to melt a small volume of gallium around the entrant well of the cell when initiating the melt. The recommended practice for realizing the gallium melt by national standards laboratories requires two solid/liquid interfaces. An inner liquid interface exists at the reentrant well with an outer liquid interface completely surrounding the inner interface at the con tainer wall. For a detailed description of the liquid/solid/liquid interfaces in the realization of the gallium melt see NIST Note 1265.

Verify that the inner melt heater is securely connected to the back of the instru ment. Remove the inner melt heater from the storage well and carefully insert it through the holes in the top insulation plugs and into the entrant well of the gal lium cell. Make sure that the heater cartridge is completely inserted to the bot tom of the cell’s entrant well.

8.7 Auto Program

The Model 9230 is designed to automate the gallium cell melt plateau. This is accomplished through the use of the Auto Program, a microprocessor-con trolled program that determines set temperatures, scan rates, duration times, Peltier module configurations and melt heater controls. By controlling all of these parameters in the proper order, a temperature profile can be maintained in the block assembly that assures a uniform melt, maintains the melt over long

Page 63

8 Melting Point of Gallium Realization

Auto Program

periods of time, properly refreezes the cell and keeps the cell ready for the next melt cycle. The Auto Program is illustrated in Figure 1.

8.7.1 Starting the Auto Program

After the frozen gallium cell has been properly installed in the instrument and the unit has been powered ON, the front panel LED display shows Auto.The instrument goes to 25°C and remains there until the SET button is pressed on the front panel starting the Auto Program. After pressing the SET button, the display changes to uuait and the Auto Program begins. The instrument auto matically resets to 29.27°C at a scan rate of 0.2°C/minute in accordance with the Auto Program (see Figure 1).

8.7.2 Generating the Melt Plateau and Removing the Inner Melt Heater

Once the unit has stabilized at 29.27°C, it waits for a minimum of 30 minutes to ensure that the gallium cell has equalized in temperature. At the end of the equalization time, the Auto Program begins to initiate the melt. The display changes to PrEP as the set temperature of the block is changed to 30.77°C. This initiates a melt on the outer surfaces of the gallium within the cell. A few minutes into the program, the unit beeps four times and the display changes to a message that flashes between PrEP and Htr on to indicate that the inner melt heater has been turned ON. The inner melt heater remains ON for a few minutes, then shuts off as the display changes back to PrEP , and the unit beeps 8 times. The user should remove the inner melt heater at this time (Note: Damage does not occur to the gallium cell if the heater is not removed, however, a shortening of the melt duration may result).

After the inner melt heater has been powered OFF, the instrument remains at

30.77°C for a few more minutes to complete the outer melt of the gallium cell. The unit then beeps 16 times, the display changes from PrEP to nnAinT and the block temperature resets to 29.86°C to maintain the melting gallium cell.

8.7.3 Calibrating Thermometers

After the melt has been initiated, a preheated monitor thermometer may be in serted to monitor the temperature of the gallium cell. Due to the heat applied to the cell by the inner melt heater, the temperature of the cell’s entrant well is higher than the gallium melting point (29.7646°C) for a short period of time. Generally, after 30 to 60 minutes, the temperature of the cell’s entrant well is sufficiently stable to begin calibrations of thermometer sensors. The duration of the melt plateau varies depending on usage, but lengths of 5 days or longer are achievable.

The two preheat wells in the block may be used to heat up the thermometers before inserting them into the cell. The preheat wells are slightly oversized so thermometers fit loosely and heat loss from the gallium cell is neither too sud den nor too severe when cold thermometers are initially placed in the preheat wells.

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8.7.4 Advancing the Auto Program and Refreezing the Gallium Cell

At the end of the melt plateau (or when the user wishes to end the plateau), the Auto Program is advanced by pressing the SET and DOWN buttons and then using the UP and DOWN buttons to select the next program state. Press SET to start the program. See Section 6.21.2, Maintain Time-out, for optional user de fined Auto Time-Out. Gallium, like water, expands in volume when freezing. Therefore, the cell must be frozen from the bottom up or there is a potential for damage to the cell. The Auto Program process ensures that the cell is properly refrozen.

The Auto Program initiates the freeze and the display shows FrEE2C at this point. The Peltier devices are reconfigured and controlled such that a large tem perature gradient is generated between the top and bottom of the block. The in strument slowly scans to 0°C to maintain the gradient over several hours.

8.7.5 Return to Standby

Upon completion of the freeze, the Auto Program returns the unit to 25°C, the front panel LED display shows Auto , and the unit remains there until the user initiates the Auto Program again by pressing the SET key.

Page 65

9 Calibration Procedure

Calibration Equipment

Note:This procedure is to be considered a general guideline. Each labora tory should write their own procedure based on their equipment and their quality program. Each procedure should be accompanied by an uncer tainty analysis also based on the laboratory’s equipment and environment.

To properly maintain the gallium cell during the melting plateau and during the refreezing process, the accuracy of the Model 9230 near the gallium melting point (29.7646°C) must be very precise, ±0.05°C or better. To achieve this, the instrument must be calibrated near this temperature. The value of R0 for this instrument refers to the resistance of the control probe at 0°C. For calibration purposes, the value of R0 is adjusted to compensate for the error at 29.27°C. The value of this parameter is set at the factory for best instrument accuracy and is located on the Report of Calibration shipped with the instrument. This parameter may be adjusted by an experienced user to improve the accuracy of the instrument. A calibration should be done at regular intervals, such as once a year, to ensure that it is operating properly.

9.1 Calibration Equipment

Calibration of the Model 9230 requires a standard thermometer and readout device that are adequately accurate. The combined accuracy of the thermometer and readout should be ±0.0125°C or better. Recommended equipment includes a laboratory grade PRT or thermistor probe with a length of 230 to 300 mm (9 to 12 inches). The calibration may be performed in a frozen Model 5943 gallium cell or in an aluminum test block that simulates the gallium cell. A small amount of silicone oil 200.05 (or equivalent) should be used in the entrant well for good thermal transfer from the cell to the thermometer.

9.2 Calibration Procedure

The accuracy of the Model 9230 at the gallium melting point (29.7646°C) is determined by the value of the calibration parameter R0. The calibration proce dure involves measuring the error between the Model 9230 and the reference thermometer at a temperature near the gallium melting point and adjusting the calibration parameter R0 as necessary to reduce the errors to within acceptable limits. The stated accuracy of the Model 9230 is given in Section 3.1, Specifi cations. For calibration purposes, the temperature is measured at 29.27°C and R0 is adjusted as applicable. The following steps may be followed to calibrate the Model 9230:

1. Enter the Manual mode of operation and set the temperature of the Model 9230 to 29.270°C with a frozen gallium cell installed. Use a small amount of silicone oil 200.05 (or equivalent) in the entrant well for good thermal transfer from the cell to the thermometer. Be sure to install the 3 top insulation plugs

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on top of the cell. Insert the reference thermometer and monitor the tempera ture of the cell with an appropriate readout.

2. Allow the system to stabilize at 29.270°C for approximately 1 to 2 hours. When the stability of the reading is less than ±0.02 over a 20 to 30 minute pe riod record the average reading of the reference thermometer. This reading gives the error of the Model 9230 and may be used for “as found” data if re quired. No further action is required if the unit is found to be within acceptable limits.

3. If step 2 above shows that the Model 9230 is out of specification or accept able limits, use the following equation to calculate a new R0 value:

= R1– (T2– T1) * (0.3850)

Where,

= the new calculated value for R0

= the old value for R0 currently programmed in the Model 9230 mem

ory

= the temperature measured in step 2 above

= the set temperature of the 9230 from step 1 above (29.270°C)

The value of R

9230. Use the following process with the front panel buttons to obtain the currently programmed value of R0:

(old R0) should be obtained from the memory of the Model

25.00 C Instrument in manual mode; well temperature displayed

S+E

Press the SET button and then the EXIT button to enter the secondary menu

SEC Flashes secondary menu

Pct Po Flashes percent power

18.0P Peltier device power in percent

Press the SET button until is displayed

ConFIG Flashes configuration menu

ProG 1 Prog 1 submenu

Press the UP button until is displayed

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CAL Calibration parameter menu

9 Calibration Procedure

Calibration Procedure

Press the SET button 5 times to access the R0 value

R0 Flashes before entering the R0 setting

99.983 Current R0 value (ohms)

4. Program the new value for R0 (R memory (see Section 6.24.1, R0).

5. Repeat steps 1 and 2 to verify that the newly calibrated Model 9230 is now within acceptable limits. If not, perform steps 3, 4, and 5 again as necessary.

Note: If it is known that the Model 9230 is more than 0.5°C out of specifica tion, such that, if the unit was calibrated at 29.270°C the cell would begin melt ing, then the above procedure should be performed below the 29.270°C set point as applicable (e.g., 28.5°C). After adjusting the unit at the lower temperature (e.g., 28.5°C), and verifying that the error had been reduced to less than

0.5°C, then the above procedure may be safely used.

) from step 3 above into the Model 9230

Page 68

10 Maintenance

The calibration instrument has been designed with the utmost care. Ease

•

of operation and simplicity of maintenance have been a central theme in the product development. Therefore, with proper care the instrument should require very little maintenance. Avoid operating the instrument in an oily, wet, dirty, or dusty environment.

If the outside of the instrument becomes soiled, it may be wiped clean

•

with a damp cloth and mild detergent. Do not use harsh chemicals on the surface, which may damage the paint.

It is important to keep the well of the instrument clean and clear of any

•

foreign matter.

The instrument should be handled with care. Avoid knocking or dropping

•

the instrument.

Examine the gallium cell for deformities before inserting it in the well. If

•

there is any chance of jamming the cell in the well, file or grind off the protuberance.

• Do not drop the probes into the well. This type of action can cause damage to the entrant well of the gallium cell.

• If a hazardous material is spilled on or inside the equipment, the user is responsible for taking the appropriate decontamination steps as outlined by the national safety council with respect to the material.

• If the mains supply cord becomes damaged, replace it with a cord with the appropriate gauge wire for the current of the instrument. If there are any questions, call Hart Scientific Customer Service for more information.

•

Before using any cleaning or decontamination method except those rec ommended by Hart, users should check with Hart Scientific Customer Service to be sure that the proposed method does not damage the equip ment.

•

If the instrument is used in a manner not in accordance with the equip ment design, the operation of the instrument may be impaired or safety hazards may arise.

•

Do not drop the gallium cell into the instrument well. This type of action can cause a shock to the control sensor, thermoelectric modules, or dam age the cell.

10 Maintenance

Page 69

11 Troubleshooting

This section contains information on troubleshooting, CE Comments, and a wiring diagram.

11.1 Troubleshooting Problems, Possible Causes, and Solutions

In the event that the instrument appears to function abnormally, this section may help to find and solve 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 problem cannot otherwise be solved, contact Hart Scientific Customer Ser vice for assistance (1-801-763-1600). Be sure to have the model number and serial number of your instrument available.

Problem Possible Causes and Solutions

Incorrect temperature reading

Incorrect R0 parameter. Find the value for R0 on the Report of Calibration that was shipped with the instrument (or from subsequent calibrations of the instrument). Reprogram the parameter into the Model 9230 memory (see Section

6.24.1, R0). Allow the instrument to stabilize and verify the accuracy of the temperature reading.

Blank display after mains power applied

The Instrument heats or cools too quickly or too slowly

Controller locked up. The controller may have locked up due to a power surge or other aberration. Initialize the system by performing the Factory Reset Sequence.

Factory Reset Sequence. Hold the SET and EXIT buttons down at the same time while powering on the instrument. After the instrument displays release the buttons. The display shows plays the firmware version, and then displays ter reset sequence, all of the configuration parameters are reset to their default values. Reprogram the R0 parameter into the Model 9230 memory (see Sec tion 6.24.1, R0) and any other applicable configuration parameters. Allow the instrument to stabilize and verify the accuracy of the temperature reading.

Blown fuse. A fuse may have blown due to a power surge or failure of a com ponent. Replace the fuse once. If the fuse blows a second time, it is likely caused by the failure of a component. Always replace the fuse with one of the same rating, voltage, and type. Never replace the fuse with one of a higher cur rent rating.

Incorrect scan and scan rate settings. The scan and scan rate settings may be set to unwanted values. Check the Scan and Scan Rate settings. The scan may be off (if the unit seems to be responding too quickly). The scan may be on with the Scan Rate set low (if unit seems to be responding too slowly).

-init-

, then displays

Auto

. After performing the mas

9230

-init-

, then dis

Page 70

9230 Maintenance System

User’s Guide

Problem Possible Causes and Solutions

The display shows any of the following:

err 2 , err 3 , err 4,orerr5

The display shows

After starting the Auto Program the display shows

uuAit

n’t go into

err 1 ,

PrEP

err

and does

Controller problem. The error messages signify the following problems with the controller.

Err 1

- a RAM error

Err 2

- a NVRAM error

Err 3

- a Structure error

Err 4

- an ADC setup error

Err 5

- an ADC ready error

Initialize the system by performing the Factory Reset Sequence describe above.

Defective control sensor. The control sensor may be shorted, open or other wise damaged. Disconnect the power cord from the instrument. Looking at the front of the instrument (display), remove the front panel and right side panel. Locate the analog control board (on the block side of the electronics panel). The Molex connector at the top of the board connects the control probe to the controller (see wiring diagram, connector J4). Remove the connector and mea sure the resistance of the control sensor. It should be approximately 110 ohms at room temperature. If it measures close to this, make sure that it is securely re-connected to the controller, replace the panels and reapply power to the in strument. If the error message returns, there is a problem with the controller.

Improper freezing. The Auto Program of the instrument is designed to monitor power levels and scan rates during the freezing cycle. If an unacceptable level or rate is detected, the unit will show To prevent any damage from occurring to the cell, remove it immediately and freeze it manually. To freeze manually, place the lower 1/3 of the cell in an ice bath with the top 2/3 exposed to the ambient air for approximately one hour until the cell freezes. The instrument may be reset by pressing any of the front panel buttons, but if the error message continues, the unacceptable freeze conditions are still present. Power the unit OFF and wait a few minutes. Then power the unit ON and reset the instrument by pressing any of the front panel buttons to see if the problem has been eliminated.

Ambient temperature may be changing too rapidly. Rapid changes in the ambient temperature of more than ±1.0°C reduce the stability of the instrument.

The Auto Program monitors the stability of the block at 29.27°C and if it is too unstable the melt does not proceed. Check the ambient temperature around the instrument for rapid changes. Avoid drafty areas.

err 8

and the beeper alarm will sound.

11.2 Comments

11.2.1 EMC Directive

Hart Scientifics’ equipment has been tested to meet the European Electromag netic Compatibility Directive (EMC Directive, 89/336/EEC). The Declaration of Conformity for your instrument lists the specific standards to which the unit was tested.

11.2.2 Low Voltage Directive (Safety)

In order to comply with the European Low Voltage Directive (73/23/EEC), Hart Scientific equipment has been designed to meet the IEC 1010-1 (EN 61010-1) and the IEC 1010-2-010 (EN 61010-2-010) standards.

Fluke 9230 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of Contents

Figures and Tables