Newport 3150 User Manual

Model 3150
High Power Temperature Controller

User’s Manual

Corporate Headquarters Canada Italy Netherlands Taiwan R.O.C.

Newport Corporation Telephone: [phone] Telephone: [phone] Telephone: [phone] Telephone: [phone]
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Irvine, CA 92714

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Belgium

Germany

Telephone: [phone] Telephone: [phone]
Facsimile: 016-402227 Facsimile: 06151-36 21-52

Newport Corporation, Irvine,
California, has been certified
compliant with ISO 9002 by the
British Standards Institution.

Limited Warranty

Newport warrants that this product will be free from defects in materials and workmanship for a period of two
years from the date of shipment. If any such product proves defective during the applicable warranty period,
Newport, at its option, either will repair the defective product without charge for parts and labor or will provide a
replacement in exchange for t he defective product.

In order to obtain service under this warranty, the customer must notify Newport of the defect before the
expiration of the warranty period and make suitable arrangements for the performance of service. In all cases the
customer will be responsible for packaging and shipping the defective product back to the service center specified
by Newport, with shipping charges prepaid. Newport shall pay for the return of the product to the customer if the
shipment is within the continental United States, otherwise the customer shall be responsible for all shipping
charges, insurance, duties and taxes, if the product is returned to any other location.

This warranty shall not apply to any defect, failure or damage caused by improper use or failure to observe proper
operating procedures per the product spec i f i c a tion or ope r a tors manual or im prope r or ina de qua te maintenance a nd
care. Newport shall not be obligated to furnish service under this warranty 1) to repair damage resulting from
attempts by personnel other than Newport’s representatives to repair or service the product; 2) to repair damage
resulting from improper use or connection to incompatible equipment; 3) to repair damage resulting from
operation outside of the operating or environmental specifications of the product.

THIS PRODUCT IS NOT DESIGNED FOR USE IN MEDICAL INSTRUMENTS WHERE MALFUNCTION
OF SUCH PRODUCTS CAN REASONABLY BE EXPECTED TO RESULT IN PERSONAL INJURY OR
DEATH.

NEWPORT’S LIABILITY FOR THE MERCHANTABILITY AND USE OF THE PRODUCT IS EXPRESSLY
LIMITED TO ITS WARRANTY SET OUT ABOVE. THIS DISCLAIMER AND LIMITED WARRANTY IS
EXPRESSLY IN LIEU OF ANY AND ALL REPRESENTATIONS AND WARRANTIES EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY
OR OF FITNESS FOR PARTICULAR PURPOSE, WHETHER ARISING FROM STATUTE, COMMON LAW,
CUSTOM OR OTHERWISE. THE REMEDY SET FORTH IN THIS DISCLAIMER AND LIMITED
WARRANTY SHALL BE THE EXCLUSIVE REMEDIES AVAILABLE TO ANY PERSON. NEWPORT
SHALL NOT BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL
DAMAGES RESULTING FROM THE USE OF THIS PRODUCT OR CAUSED BY THE DEFECT, FAILURE
OR MALFUNCTION OF THIS PRODUCT, NOR ANY OTHER LOSSES OR INJURIES, WHETHER A
CLAIM FOR SUCH DAMAGES, LOSSES OR INJURIES IS BASED UPON WARRANTY, CONTRACT,
NEGLIGENCE, OR OTHERWISE. BY ACCEPTING DELIVERY OF THIS PRODUCT, THE PURCHASER
EXPRESSLY WAIVES ALL OTHER SUCH POSSIBLE WARRANTIES, LIABILITIES AND REMEDIES.
NEWPORT AND PURCHASER EXPRESSLY AGREE THAT THE SALE HEREUNDER IS FOR
COMMERCIAL OR INDUSTRIAL USE ONLY AND NOT FOR CONSUMER USES AS DEFINED BY THE
MAGNUSOM-MOSS WARRANTY ACT OR SIMILAR STATE CONSUMER WARRANTY STATUTE.

©1996, Newport Corporation
Irvine, California, USA
Part No. 24594-01
IN-08972
Rev. C
Printed 11-Apr-00

EC DECLARATION OF CONFORMITY

Model 3150 High Power Temperature Controller

We declare that the accompanying product, identified with the “ ” mark, meets
all relevant requirements of Directive 89/336/EEC and Low Voltage Directive
73/23/EEC.

Compliance was demonstrated to the following specifications:

EN50081-1 EMISSIONS:

Radiated and conducted emissions per EN55011, Group 1, Class A

EN50082-1 IMMUNITY:

Electrostatic Discharge per IEC 1000-4-2, severity level 3
Rated Emission Immunity per IEC 1000-4-3, severity level 2
Fast Burst Transients per IEC 1000-4-4, severity level 3
Surge Immunity per IEC 1000-4-5, severity level 3

IEC SAFETY:

Safety requirements for electrical equipment specified in IEC 1010-1

.

VP European Operations General Manager-Precision Systems
Zone Industrielle 1791 Deere Avenue
45340 Beaune-la-Rolande, France Irvine, Ca. USA

______________________ ______________________

Alain Danielo Jeff Cannon

i

Table of Contents

1 General Information______________________________________________ 1

1.1 Introduction_______________________________________________________ 1

1.2 Product Overview __________________________________________________ 1

1.3 Available Options and Accessories ____________________________________ 2

1.4 Safety Terms and Symbols___________________________________________ 2

1.4.1 Terms _______________________________________________________________ 2

1.4.2 Symbols _____________________________________________________________ 3

1.5 General Warnings and Cautions ______________________________________ 3

2 System Operation_________________________________________________ 5

2.1 Introduction_______________________________________________________ 5

2.2 Installation________________________________________________________ 5

2.2.1 AC Power Considerations________________________________________________ 5

2.2.2 Tilt-Foot Adjustment ___________________________________________________ 5

2.2.3 Rack Mounting________________________________________________________ 6

2.2.4 Ventilation Requirements________________________________________________ 6

2.2.5 Power-Up Sequence ____________________________________________________6

2.2.6 Quick Start ___________________________________________________________ 6

2.3 Introduction to the 3150 Front Panel __________________________________ 7

2.3.1 Model 3150___________________________________________________________ 7

2.4 General Operation__________________________________________________ 8

2.4.1 Display Elements ______________________________________________________ 8

2.4.1.1 Static Fields ________________________________________________________8

2.4.1.2 Non-Editable Data Fields ______________________________________________8

2.4.1.3 Editable Data Fields __________________________________________________8

2.4.1.3.1 Changing Data Fields ______________________________________________ 8

2.4.1.4 Soft Keys __________________________________________________________9

2.4.2 Function Keys_________________________________________________________ 9

2.4.3 Menu Structure_______________________________________________________ 10

2.4.4 Master Display _______________________________________________________11

2.4.5 Main Menu __________________________________________________________ 11

2.4.6 Configure Menu ______________________________________________________12

2.4.7 System Configure Screen _______________________________________________ 12

2.4.8 Save/Recall Screen____________________________________________________ 14

2.4.9 Calibration Screen ____________________________________________________14

2.4.10 Configure Communications Screen _______________________________________ 14

2.4.10.1 Error Message Control _____________________________________________15

2.5 Rear Panel Familiarization__________________________________________ 15

2.5.1 GPIB Connector ______________________________________________________ 15

ii

2.5.2 RS-232 Connector ____________________________________________________ 15

2.5.3 Input Power Connector ________________________________________________ 15

2.5.4 Ground Post

_____________________________________________________ 16

2.6 Warm Up and Environmental Consideration___________________________16

3 Temperature Controller Operation__________________________________ 17

3.1 General Features __________________________________________________17

3.2 TEC Safety Features _______________________________________________17

3.2.1 Conditions Which Will Automatically Shut Off the TEC Output ________________ 17

3.3 The TEC Connectors_______________________________________________18

3.3.1 TEC Interlock _______________________________________________________ 18

3.3.2 TEC Grounding Consideration __________________________________________ 18

3.4 TEC Operation____________________________________________________18

3.4.1 TEC Main Screen_____________________________________________________ 18

3.4.2 TEC Setup Screen ____________________________________________________ 19

3.4.2.1 The



and

Soft Keys ____________________________________________ 20

3.4.2.2 Sensor (Sens) ______________________________________________________ 20

3.4.2.3 Mode ____________________________________________________________ 21

3.4.2.3.1 Constant Temperature Mode (Const T)_______________________________ 21

3.4.2.3.2 Constant Resistance/Reference Mode (Const R)________________________ 21

3.4.2.3.3 Constant Current Mode (Const Ite) __________________________________ 21

3.4.2.3.4 Effects of Calibration on TEC modes ________________________________ 21

3.4.2.4 Gain _____________________________________________________________ 22

3.4.2.5 Limits____________________________________________________________ 22

3.4.2.5.1 TE Current Limit (Lim Ite) ________________________________________ 22

3.4.2.5.2 Temperature Limits (Lim Th and Lim Tl)_____________________________ 23

3.4.2.5.3 Resistance/Reference Limits (Lim Rh/vhI/ih and Lim Rl/vlO/il) ___________ 23

3.4.2.6 Tolerances (Tol Time and Tol Temp) ___________________________________ 23

3.4.2.7 Vpow, Ths, and Tamb _______________________________________________ 23

3.4.2.8 C1, C2, C3, and Ro _________________________________________________ 23

3.4.3 Thermistor and Thermistor Current Selection _______________________________ 24

3.4.3.1 Introduction _______________________________________________________ 24

3.4.3.2 Thermistor Range __________________________________________________ 24

3.4.3.3 Temperature Resolution______________________________________________ 25

3.4.3.4 Selecting Thermistor Current__________________________________________ 26

3.4.3.5 Selecting Thermistors _______________________________________________ 26

3.4.3.6 The Steinhart-Hart Equation __________________________________________ 27

3.4.3.7 Table of Constants __________________________________________________ 29

3.4.4 AD590 and LM335 ___________________________________________________ 29

3.4.4.1 General___________________________________________________________ 29

3.4.4.2 AD590 Sensor _____________________________________________________ 29

3.4.4.3 LM335 Sensor _____________________________________________________ 30

3.4.4.4 Determining C1 and C2 for the AD590 and LM335 ________________________ 31

3.4.4.4.1 One Point Calibration Method______________________________________ 31

3.4.4.4.2 Two Point Calibration Method _____________________________________ 32

iii

3.4.5 RTD Sensors_________________________________________________________ 33

3.4.5.1 RTD Constants _____________________________________________________ 33

4 Principles of Operation ___________________________________________ 35

4.1 Introduction______________________________________________________ 35

4.2 TEC Controller Theory of Operation_________________________________ 36

4.2.1 TEC Interface ________________________________________________________ 36

4.2.2 Limit DAC __________________________________________________________ 36

4.2.3 Set Point DAC _______________________________________________________ 37

4.2.4 A/D Converter _______________________________________________________ 37

4.2.5 Sensor Select_________________________________________________________37

4.2.6 Difference Amplifier __________________________________________________37

4.2.7 Proportional Amplifier _________________________________________________ 37

4.2.8 Integrator ___________________________________________________________ 37

4.2.9 Bipolar Output Stage __________________________________________________ 38

4.2.9.1 Current Limiting____________________________________________________38

4.2.9.2 Current Limit Condition Sensing _______________________________________ 38

4.2.9.3 Voltage Controlled Current Source _____________________________________38

4.2.9.4 Voltage Limit Condition Sensing _______________________________________ 38

4.2.10 TEC Control Modes ___________________________________________________ 38

4.2.10.1 T Mode _________________________________________________________ 38

4.2.10.2 R Mode_________________________________________________________ 39

4.2.10.3 I

TE

Mode ________________________________________________________ 39

4.3 Microprocessor Board _____________________________________________ 40

4.3.1 Microprocessor_______________________________________________________40

4.3.2 Memory ____________________________________________________________41

4.3.3 Serial Interface _______________________________________________________ 41

4.3.4 Front Panel Interface___________________________________________________ 41

4.3.5 GPIB Interface _______________________________________________________ 41

4.4 Power Supplies____________________________________________________ 41

4.4.1 TEC Power Supplies___________________________________________________ 41

4.4.2 Main Supply _________________________________________________________ 42

5 Tips and Techniques _____________________________________________ 43

5.1 Introduction______________________________________________________ 43

5.2 TEC Limits_______________________________________________________ 43

6 Maintenance ___________________________________________________ 45

6.1 Introduction______________________________________________________ 45

6.2 Fuse Replacement _________________________________________________ 45

6.3 Cleaning _________________________________________________________ 45

7 Calibration_____________________________________________________ 47

iv

7.1 Calibration Overview ______________________________________________47

7.1.1 Environmental Conditions______________________________________________ 47

7.1.2 Warm-Up___________________________________________________________ 47

7.2 TEC Calibration __________________________________________________47

7.2.1 Recommended Equipment______________________________________________ 47

7.2.2 Local Operation Thermistor Calibration ___________________________________ 48

7.2.3 Remote Operation Thermistor Calibration__________________________________ 48

7.2.4 Local Operation AD590 Sensor Calibration ________________________________ 49

7.2.5 Remote Operation AD590 Sensor Calibration_______________________________ 49

7.2.6 Local Operation LM335 Sensor Calibration ________________________________ 50

7.2.7 Remote Operation LM335 Sensor Calibration ______________________________ 50

7.2.8 Local Operation RTD Calibration ________________________________________ 51

7.2.9 Remote Operation RTD Calibration ______________________________________ 51

7.2.10 RTD Lead Resistance Calibration (Offset Null) _____________________________ 51

7.2.11 Local Operation ITE Current Calibration __________________________________ 52

7.2.12 Remote Operation ITE Current Calibration_________________________________ 52

8 Factory Service _________________________________________________ 55

8.1 Introduction ______________________________________________________55

8.2 Obtaining Service__________________________________________________55

9 Error Messages _________________________________________________ 59

9.1 Introduction ______________________________________________________59

10 Specifications _________________________________________________ 61

10.1 Temperature Controller Specifications________________________________61

10.2 General Specifications______________________________________________62

Tables

Table 1 - TEC Connector Pinout_____________________________________________________ 18
Table 2 - Comparison of Curve Fitting Equations _______________________________________ 28
Table 3 - Thermistor Constants______________________________________________________ 29
Table 4 - RTD Constants___________________________________________________________ 33
Table 5 - Recommended Test Equipment_______________________________________________ 48
Table 6 - Error Codes _____________________________________________________________ 59

Figures

Figure 1 - Model 3150 Front Panel____________________________________________________ 7
Figure 2 - A Sample Screen with Various Data Fields _____________________________________ 9
Figure 3 - Model 3150 Menu Structure________________________________________________ 10
Figure 4 - Master Display __________________________________________________________ 11
Figure 5 - Main Menu _____________________________________________________________ 12
Figure 6 - Configure Menu _________________________________________________________ 12

v

Figure 7 - Save/Recall Screen _______________________________________________________ 14
Figure 8 - Communications Screen ___________________________________________________ 14
Figure 9 - Rear Panel______________________________________________________________ 15
Figure 10 - TEC Main Screen _______________________________________________________ 19
Figure 11 - TEC Setup Screens ______________________________________________________ 20
Figure 12 - Thermistor Temperature Range_____________________________________________25
Figure 13 - Thermistor Resistance versus Temperature____________________________________28
Figure 14 - AD590 Nonlinearity _____________________________________________________ 30
Figure 15 - 3150 Block Diagram _____________________________________________________ 35
Figure 16 - TEC Board Diagram_____________________________________________________ 36
Figure 17 - Microprocessor Board Block Diagram_______________________________________ 40
Figure 18 - Power Supply Block Diagram______________________________________________ 41

1

CHAPTER 1

1 General Information

1.1 Introduction

This chapter describes the features, options, accessories, and specifications of the
Model 3150.

1.2 Product Overview

PRODUCT FEATURES

 GPIB/IEEE 488.2 and RS-232C Interfaces
 Temperature Controller

• 350 Watt (up to 15A, and up to 28V, but not more than 350 Watts)

• Ultra stable bipolar output

• Thermistor, AD590, LM335, and Pt RTD sensors

The Model 3150 Temperature Controller is a result of Newport’s continuing
commitment to provide advanced instrumentation at affordable prices.

High Power Temperature Controller Fulfills All Your Thermo
Electric (TE) Cooling Needs

The 350 Watt Temperature Controller is offered to meet your most demanding TE
cooling needs. It may be operated in one of three modes:

• Constant Tempe rature

• Constant Resistance

• Constant TE Current

Short term stability is better than 0.0005°C while long term stability is better than

0.001°C. Four sensor types are compatible with this TEC:

• Thermistors

• AD590 series

• LM335 series

• 100

Ω

Platinum RTDs

With the sensor’s calibration constants, the actual temperature is displayed in °C on
the front panel.

2 Chapter 1 General Information

Intuitive Controls and LCD Display Simplify Control and
Test Procedures

Improved data presentation and system control are achieved using a LCD display.
A MASTER display shows the entire system configuration as well as TEC status.
“Soft Keys” guide you through initial system setup routines and operation. Real­time control of an output is accomplished either by entering the set point via the
cursor keys or control knob. MENU and FUNC keys access saved system
configurations and repetitive procedures. All controls are clearly marked and
instructions easily understood for simple operation.

GPIB/IEEE-488.2 and RS232 Interfaces Gives Power to
Remotely Control and Collect Data.

For ultimate control a GPIB/IEEE-488.2 interface is available. All control and
measurement functions are accessible via the GPIB interface. In addition, a standard
serial RS-232C port allows simpler interfacing to a PC. As your instrumentation
needs change the Model 3150 Temperature Controller will adapt to all your new
applications giving you the ultimate in flexible laboratory equipment.

1.3 Available Options and Accessories

Accessories
3150-02 Temperature Controller Cable
3150-04 Temperature Controller/Mount Cable

300-16 10.0 k

Ω

thermistor (± 0.2°C)
300-22 AD592CN IC Sensor
3150-RACK Rack Mount Kit

Newport Corporation also supplies temperature controlled mounts and other
accessories. Please consult with your representative for additional information.

1.4 Safety Terms and Symbols

1.4.1 Terms

The following safety terms are used in this manual:

The

WARNING

heading in this manual explains dangers that could result in

personal injury or death.

The

CAUTION

heading in this manual explains hazards that could damage the

instrument.

Chapter 1 General Information 3

In addition, a

NOTE

heading gives information to the user that may be beneficial in

the use of this instrument.

1.4.2 Symbols

The following symbols are used in this manual and on the instrument:

Power Off

Power On

!

Refer to the documentation.

Earth Ground

1.5 General Warnings and Cautions

The following general warning and cautions are applicable to this instrument:

WARNING

This instrument is intended for use by qualified personnel who

recognize shock hazards or laser hazards and are familiar with safety

precautions required to avoid possible injury. Read the instruction

manual thoroughly before using, to become familiar with the

instrument’s operations and capabilities.

WARNING

The American National Standards Institute (ANSI) states that a shock

hazard exists when probes or sensors are exposed to voltage levels

greater then 42 VDC or 42V peak AC. Do not exceed 42V between

any portion of the Model 3150 (or any attached detector or probe) and

earth ground or a shock hazard will result.

CAUTION

There are no serviceable parts inside the Model 3150. Work performed

by persons not authorized by Newport Corporation may void the

warranty. For instructions on obtaining warranty repair or service

please refer to Chapter 8 of this manual.

5

CHAPTER 2

2 System Operation

2.1 Introduction

This chapter describes how to operate the Model 3150. Unless otherwise noted,
“3150” refers to the Model 3150.

2.2 Installation

CAUTION

Although ESD protection is designed into t he 3150, operation in a

static-fee work area is recommended.

2.2.1 AC Power Considerations

The 3150 can be configured to operate at a nominal line voltage of 100, 120, 220, or
240 VAC. Normally, this is done at the factory and need not be changed before
operating the instrument. However, be sure that the voltage setting is correct on the
power input module and correct fuses are installed per section 6.2 before connecting
to an AC source. The 3150 is shipped set for 120 VAC and a caution sticker is
placed on the input power connector.

CAUTION

Do not exceed 250VAC on the line input.

Do not operate with a line voltage that is not within ±10% of the

line setting. Too low of an input voltage may cause excessive

ripple on the DC supplies. Too high of an input voltage will cause

excessive heating.

WARNING

To avoid electrical shock hazard, connect the

instrument to properly earth-grounded, 3-prong

receptacles only. Failure to observe this precaution

can result in severe injury or death.

2.2.2 Tilt-Foot Adjustment

The 3150 has front legs that extend to make it easier to view the LCD display. To
use them, place the 3150 on a stable base and rotate the legs downward until they
lock into position.

6 Chapter 2 System Operation

2.2.3 Rack Mounting

The 3150 may be rack mounted by using a 3150 rack mount kit. All rack mount
accessory kits contain detailed mounting instructions.

2.2.4 Ventilation Requirements

Rear panel area needs 2 to 4 inches of clearance for air circulation.

2.2.5 Power-Up Sequence

With the 3150 connected to an AC power source, set the power switch to “I” to
supply power to the instrument and start the power-up sequence.

During the power-up sequence, the following takes place. For about 5 seconds an
initialization screen is displayed. The software version is displayed in the lower left
corner of the screen. During this time a self-test is performed to ensure that the 3150
hardware and software are communicating. If the 3150 cannot successfully complete
this test, an error message will be displayed.

NOTE

In the even the 3150 is powered off, it must remain off for a

minimum of 60 seconds

before reapplying power. Not doing so

may result in the internal power supply failing to start, and an error

message will be reported. There is no risk of damage to the unit if

such a condition occurs.

After this test, the 3150 is configured to the state it was in when the power was last
shut off and displays the master display.

2.2.6 Quick Start

After the power-on sequence is complete, the 3150 goes to the Master screen. To set
up the TEC, press the

SETUP

softkey button. The up and down cursor keys will
allow the selection of all the TEC parameters, using the cursor keys and the dial set
the parameter values. When finished, return the TEC to the Master screen by
pressing the

MASTER

button.

Enter the desired set point value using the cursor keys or the dial. Press the

TEC On

key to operate the TEC. The LED illuminates to indicate TEC operation. To turn the
TEC off, press the

TEC On

key again.

Chapter 2 System Operation 7

2.3 Introduction to the 3150 Front Panel

2.3.1 Model 3150

Described below are the functions of each area of the Model 3150 front panel, as
shown in Figure 1.

Figure 1 - Model 3150 Front Panel

1.

Power On/Off Switch

- Switches on/off the AC power to the unit.

2.

TEC On LED

- Indicates TEC output is on.

3.

TEC On Button

- Turns the TEC output on/off.

4.

Display Soft Keys

- These are the two dark keys located to the right of the
display. T he function of these keys varies depending on what menu is displayed.
See section 2.4.1.4 for a complete description of soft keys.

5.

MASTER Key

- switches to the master display from any screen in the system

(see section 2.4.4).

6.

Cursor Control Keys

- Moves cursor up or down between editable data fields.
The left arrow decrements values in numerical entry fields, or as a previous
choice in a multi-choice entry field. The right arrow increments values in
numerical entry fields, or as a next choice in multi-choice entry fields. See
section 2.4.1.3 for a description of data fields.

7.

MENU Key

- Switches to the main menu from any screen in the system (see

section 2.4.5).

8.

FUNCTION Key

- Used to execute user macros and special functions (see

section 2.4.2).

9.

SHIFT Key

- Toggles between the outer and inner set of soft keys (see section

2.4.1.4).

10.

Remote LED

- Indicates 3150 is in remote mode.

11.

Knob

- Used to continuously vary certain parameters. The knob has an
acceleration factor that causes the rate of change to increase as the knob is
turned faster. Turning slowly allows for a fine adjustment at the smallest
displayed decimal place.

8 Chapter 2 System Operation

2.4 General Operation

2.4.1 Display Elements

The Model 3150 uses a character display to depict information about the current state
of the system. The display can be broken down into four basic elements: static fields,
non-editable data fields, editable data fields, and soft key labels (see Figure 2).

2.4.1.1 Static Fields

Static fields are elements on the display which do not change from moment to
moment. These can include screen titles and error messages.

2.4.1.2 Non-Editable Data Fields

Non-editable data fields are used mainly to display read back information, such as
temperature, TEC current, etc. These fields can have a prefix or suffix label, such as
“T=” or “I=”, and are periodically updated by the system.

2.4.1.3 Editable Data Fields

Editable data fields are used for TEC and system settings such as ITE set point,
temperature set point, display contrast, etc. An editable field has three distinct
display states: focused, non-focused, and read-only.

The focused state indicates that the field has the input “focus.” When a field has the
focus, a right pointing arr ow (→) is placed to the left of the field. Any keyboard

entry or knob adjustment will be applied to the field, and only one field at a time on
the display can have focus. Move between fields using the up and down arrow keys.

The non-focused state indicates that the field is editable, but does not currently have
the focus. These fields are indicated with a right pointing triangle () to the left of

the field. Using the up and down arrows, focus can be moved to these fields.

When the editable data field is in the read-only state, it looks and acts exactly like a
non-editable data field. Like the non-editable data field, it cannot have focus, and the
up or down arrow keys will skip over the field. This state is used primarily to lockout
specific data elements from front panel change when the Model 3150 is in remote
mode. Any IEEE-488 or RS-232 communication will place the unit in remote mode,
and editable fields that are protected during remote operations change to the read
only state.

2.4.1.3.1 Changing Data Fields

A data field can only be changed from the front panel when the field is the focus.
Some fields are numeric-based, such as current set point or temperature limits. Other
fields are multi-choice fields, such as Yes/No fields. Both types are changed with the
left and right arrows or the knob.

Chapter 2 System Operation 9

2.4.1.4 Soft Keys

Soft key labels are labels for the two gray buttons located to the immediate right of
the display. Each label either indicates the action that is performed when the
corresponding key is pressed (such as changing screens), or the state of a data
element in the system (such as on/off toggle switch). In the first case, pressing the
corresponding soft key will cause the action to happen, such as changing to the setup
screen when the

Setup

soft key is pressed from a TEC’s main screen. In the second

case, pressing the soft key will change the state of the associated data value.

Like the editable data fields above, certain soft keys are programmed to enter a
“display-only” mode when the unit enters remote mode. Display-only soft keys are
displayed in lower case, and will not function until the unit returns to local mode.

On some screens, such as the configure menu (see Figure 6), there are more than two
soft key selections. In this case, the active soft keys have a left pointing arrow (←) to

the right of the soft key label. Pressing the

SHIFT

key will toggle between the outer

and inner two soft keys.

Figure 2 - A Sample Screen with Various Data Fields

2.4.2 Function Keys

For macros and special functions, the

FUNC

key is used both to execute and to enter
the setup screen on the particular function. For example, if the 3150 supported a
special function assigned to the up arrow key, to enter the setup screen of this
function, pr ess and hold the

FUNC

key, then press the up arrow key, then release
both. This would enter the setup screen for this function. To execute this function,
press and release the

FUNC

key, then press and release the up arrow key. If

functions are not setup/supported for a particular key, the 3150 will beep. The 3150

→→→→

Ts = 25.00 °C OutT
T = 23.50 °C
Ite= 0.00 A V=0.00
T OutT SETUP

Static Field

Non-editable
data field

Focused editable
data field

10 Chapter 2 System Operation

supports assignment of macros to the arrow keys, the

MASTER

key, the

MENU

key, and the

TEC

key.

2.4.3 Menu Structure

Figure 3 - Model 3150 Menu Structure

Master Display

System

Configure Menu

Save/Recall

Communications

Local

Calibration

Setup

Main Menu

Chapter 2 System Operation 11

2.4.4 Master Display

The Master Display is shown in Figure 4. This is the highest level display and
indicates the status of the temperature controller.

→→→→

Ts = 25.00 °C
T = 23.50 °C
Ite= 25.00 A V=0.00
SETUP

Figure 4 - Master Display

The Master Display can be accessed from any screen in the system by pressing

MASTER

.

2.4.5 Main Menu

The Main Menu is shown in Figure 5. This is the second highest menu and is used to
access four general system functions:

1.

COMM

- Pressing the adjacent soft key gives access to

the GPIB and RS232 parameters.

2.

LOCAL

- When the unit is in remote mode, either

through GPI B or RS-232C communications, the

Local

soft key will be available. Pressing it returns the 3150 to a
local state. When in local mode, this key does not appear
on the display. The 3150 is placed in remote mode
through GPI B or RS232 communication, or during the
execution of a macro or special function.

3.

CONFIG

- Pressing the adjacent soft key gives access to
the general configuration menu, with soft keys to access
system configure, save/recall, and calibration screens.

12 Chapter 2 System Operation

Main Menu COMM

←←←←

LOCAL
CONFIG

←←←←

Figure 5 - Main Menu

2.4.6 Configure Menu

Config SYSTEM

←←←←

CAL
SAV/RCL

←←←←

Figure 6 - Configure Menu

The configure menu provides access to the system configuration, calibration, and
save and recall screens.

2.4.7 System Configure Screen

→→→→

Contrast= 11 %



Brightness= 100 %



Lockout dial= No



Lockout pad= No

→→→→

Audible beep= Yes





Key Rate= Fast



Dial Rate= Fast

The system configure screen controls basic operation of the 3150 system.

Brightness

varies the backlighting intensity.

Contrast

is used to optimize the viewing angle.

Chapter 2 System Operation 13

Lockout dial

disables the dial to avoid accidental changes in active data fields if the

dial is bumped.

Lockout pad

locks out the left and right arrow keys, the data entry portion on the

keypad. Navigation keys, such as up and down,

MENU, MASTER

, and

FUNC

continue to work.

Note that both the Lockout dial and Lockout pad settings are temporarily suspended
while in the Configure System Screen, allowing the dial and keypad lockout settings
to be changed while in this screen..

Audible Beep

controls the system’s audible beeper. The beeper indicates errors,

invalid data entry, and other situations where the 3150 needs to alert the user.

Key Rate

- this controls the speed at which, when a key is held down, it repeats.

Settings are

Slow, Medium

, and

Fast

.

Dial Rate

- like the

Key Rate

setting, this controls the acceleration of the dial as it is

turned. Settings are

Slow, Medium

, and

Fast

.

14 Chapter 2 System Operation

2.4.8 Save/Recall Screen

Save/Recall SAV

→→→→

Bin=1

RCL

Figure 7 - Save/Recall Screen

The Save and Recall functions are used to store and retrieve 3150 setup
configurations for future use. For example, a specific test setup may be saved for
later use, and then another setup may be used presently. Then, when the user desires
to perform the specific test, its setup is simply recalled.

Non-volatile memory is used for saving the instrument parameters. When a save
operation is performed, all of the parameters which are currently in effect on the
3150 are stored. The user selects a “bin” number for saving the parameters, up to the
maximum available in the instrument. Then, when that “bin” number is recalled, the
3150 is restarted and the parameters are reconfigured to the previously stored values.
A special “bin 0” is reserved for the reset state. Recalling bin 0 will reset the unit to
factory defaults.

2.4.9 Calibration Screen

Pressing the

Cal

soft key displays the TEC calibration screen. See section 7.2 for

TEC calibration.

2.4.10 Configure Communications Screen

→→→→

Err While Rmt= No



GPIB Address= 4



Speed= 9600 Baud



Terminal Mode= No

Figure 8 - Communications Screen

The

GPIB Address

is the IEEE-488 device address assigned to the 3150. Valid

addresses are 1 to 31. See the Computer Interfacing Manual for a description of the

Terminal Mode

and

Speed

.

Chapter 2 System Operation 15

2.4.10.1 Error Message Control

Error messages may appear on the display when error conditions occur which force
the output off or reflect hardware errors in the 3150. Chapter 9 contains an
explanation of the error message which may be reported by the 3150. Display of
error messages on the 3150 screen may be disabled while in remote mode by setting

Err While Rmt

to No, or by using the GPIB command

REMERR

to set this value
remotely. Errors will continue to accumulate in the error queue, but will not be
displayed on-screen.

Each press of the

MASTER

button will clear one error.

2.5 Rear Panel Familiarization

Figure 9 - Rear Panel

2.5.1 GPIB Connector

The GPIB connector, located on the back panel, allows full remote control as
described in the Computer Interfacing Manual. It accepts a standard IEEE-488 cable
for remote control, and uses Metric lock screws.

2.5.2 RS-232 Connector

The 3150 has an RS-232 connector located on the back panel. See the Computer
Interfacing Manual for a more complete description of the RS-232 interface.

2.5.3 Input Power Connector

Accepts a standard line cord for AC input. Also selects one of four AC input
settings: 100V, 120V, 220V, and 240V. The cord must be removed to change the
setting. A small screwdriver will open the top of the module and expose the rotary
switch. Select the range that is closest to your expected nominal RMS line voltage.
The voltage selection is set for 120 VAC prior to shipping. A caution sticker is then
placed over the input power connector to help insure the customer checks for proper
voltage.

16 Chapter 2 System Operation

CAUTION

Do not exceed 250 VAC on the line input.

Do not operate with a line voltage that is not within ±10% of the

line setting. Too low of an input voltage may cause excessive

ripple on the DC supplies. Too high of an input voltage will cause

excessive heating.

2.5.4 Ground Post

Provides access to chassis ground, which is also an earth ground as long as a
standard 3-wire line cord is used. This is a protective conductor terminal to be used
to achieve chassis grounding requirements when the main connectors don’t provide
an earth ground terminal. Use a minimum of 18 gauge wire to connect to this
terminal.

2.6 Warm Up and Environmental Consideration

Operate the 3150 at an ambient temperature in the range of 0 to +40°C. Storage
temperatures should be in the range of -20 to +60°C. To achieve rated accuracy, let

the 3150 warm up for 1 hour. For greatest accuracy, recalibrate when ambient
temperature changes more than a few degrees.

CAUTION

Operating above +40°C can cause excessive heating and possible

component failures.

17

CHAPTER 3

3 Temperature Controller Operation

3.1 General Features

The 3150 Temperature Controller is a precision thermo electric cooler controller.
Features include:

• Closed-case calibration

• Operational with most thermistors, IC and RTD temperature sensors

• Flexible setup with Save/Recall front panel functions

• High temperature stability

• Current Limit

3.2 TEC Safety Features

3.2.1 Conditions Which Will Automatically Shut Off the TEC
Output

• High Temperature Limit

• Low Temperature Limit

• R Limit

• TEC Open

• Sensor Open

• Sensor Select changed

• Sensor Shorted

• Mode Change

Clearing the appropriate bits in the TEC OUTOFF register can disable each of these
conditions. See the Computer Interfacing Manual for additional information.

18 Chapter 3 Temperature Controller Operation

3.3 The TEC Connectors

A high power 7W 2 female D-connector is used for input and output connections, as
shown by the pin out diagram below.

Pin

Description

3150-02 Cable
Color Code

A1 TE+ Red
A2 TE- Black
1 Sensor+ Green
2 Sensor- White
3 Interlock
4 Interlock
5 Ground

Table 1 - TEC Connector Pinout

3.3.1 TEC Interlock

On the TEC input/output connector pins 3 and 4 form the interlock path. The TEC
interlock functions in a normally open condition, where the output will be shutdown
only when pins 3 and 4 are shorted together.

3.3.2 TEC Grounding Consideration

The TEC output is isolated from chassis ground, allowing either output terminal to
be grounded at the user's option.

3.4 TEC Operation

3.4.1 TEC Main Screen

The TEC main screen is shown Figure 10 and described below.

A1

A2

1

2

5

3

Chapter 3 Temperature Controller Operation 19

→→→→

Ts= 25.00 °C
T= 25.00 °C
Ite= 0.00 A
I V T R C InT SETUP

←←←←

Figure 10 - TEC Main Screen

Is=, Ts=, Rs=, is=, vs=

- Indicates the set point value of current, temperature,
resistance, AD590 sensor current, or LM335 sensor voltage, respectively. In the
screen shown above, the Ts is shown.

Is, Rs, is,

and vs would be seen when

operating in those modes.

I=, T=, R=, i=, v=

- Indicates the measured value of current, temperature, resistance,

AD590 sensor current, or LM335 sensor voltage, respectively. An

err

indicates a
sensor error, usually caused by the sensor not hooked up or the wrong se nsor
selected. In the screen shown above, the T is shown. I,

R, i

, and

v

would be seen

when operating in those modes.

SETUP

- Pushing the adjacent soft key activates the setup screen.

The bottom line on the display has 6 “LED” elements, each indicating a particular
state of the TEC. They are defined as:

I

When illuminated, indicates the TEC module is in current limit.

V

When illuminated, indicates the TEC module has reached it’s
voltage limit.

T

When illuminated, indicates the TEC module is outside the
temperature limits defined by T

HI

and TLO in the setup screen.

R

When illuminated, indicates the TEC module is outside the
reference limits defined by R

HI/vHI/iHI

and RLO/vLO/iLO in the

setup screen.

C/H

When illuminated, indicates that the TEC is cooling or heating.

OutT/InT

When illuminated, indicates that the TEC is out of tolerance or in
tolerance as defined by

Tol Time

and

Tol Temp

in the setup

screen.

3.4.2 TEC Setup Screen

The TEC Setup screen is shown in Figure 11. Each section is described below in
detail.

20 Chapter 3 Temperature Controller Operation

→→→→

Sens= RTD





Mode= Const T



Gain= 30



Lim Ite= 2.0 A

→→→→

Tol Time= 5.000 S





Tol Temp= 0.20 °C



Lim Tl= 10.00 °C



Lim Th= 50.00 °C

Vpow= 10.00 V



Ths= 24.9 °C
Tamb= 23.4 °C

→→→→

C1= 3.9080 x 10-3





C2=-0.5802 x 10-6



C3=-4.272 x 10-12



R0= 100.00

ΩΩΩΩ

Figure 11 - TEC Setup Screens

3.4.2.1 The



and Soft Keys

Pushing the



(previous) soft key returns to the previous screen, while pressing the

(next) soft key advances to the next screen.

3.4.2.2 Sensor (Sens)

Selects the temperature sensor type used in your TEC mount. If the

None

is selected,

only the I

TE

mode is allo wed . This type is i ntended for applica t ions running without

a temperature sensor. See the following sections for discussions of the various sensor

Chapter 3 Temperature Controller Operation 21

types. The TEC supports the thermistor sensors (10µA and 100µA range), AD590,
LM335, and RTD sensors.

3.4.2.3 Mode

3.4.2.3.1 Constant Temperature Mode (Const T)

This mode holds the TEC at a constant temperature based on feedback from the
sensor in the TEC mount, using “

Ts=

” and “T=” variables. In this mode, the 3150
uses a control loop comparing the sensor input to the temperature set point, driving
the I

TE

current positive or negative to reach and maintain that set point. The sensor’s

input is converted to temperature for display of actual TEC temperature. The I

TE

current is also displayed in this mode.

3.4.2.3.2 Constant Resistance/Reference Mode ( Const R)

This mode operates identically to the Const T mode, but the sensor input is not
converted to temperature, and is displayed in unconverted form. Likewise, the set
point is used directly, not converted from temperature. Thermistor and RTD sensors
use resistance (“

Rs=

” and “R=” variables), LM335 sensors use millivolts (“

vs=

” and

“v=” variables), and AD590 sensors use microamps (“

is=

” and “i=” variables). Const
R is primarily intended for users who know a sensor set point in “sensor” units, not
in ºC. I

TE

current is also displayed in these modes.

3.4.2.3.3 Constant Current Mode (Const Ite)

Unlike the modes above, the Const ITE mode allows the operator to explicitly set the
amount and dir ection of current flow through the TEC, using “

Is=

” and “

Ite=

”
variables. If a sensor has been selected, the TEC temperature will be displayed.
Although temperature is not a factor in the amount or dir ection of current flow, the
high and low temperature limits are observed, and will shutdown the output if
exceeded in Const I

TE

mode, if a sensor is selected. For no temperature limits, set the
sensor type to “None.” Use caution when limits are not active, as the temperature
may exceed your TEC's thermal limits.

3.4.2.3.4 Effects of Calibration on TEC modes

On startup, the TEC performs an auto-calibration to eliminate most of the error in
ADC and DAC values. After this auto-calibration, each sensor type supported by the
TEC has an offset calibration, while the I

TE

set point and read back has a two point
calibration. These calibration constants are then used to calibrate a set point or read
back value. This includes “cross-mode” values, such as displaying actual current
while in constant temper ature mode. While the current set point calibration has no
effect in Const T mode, the read back calibration is used to more accurately display
the actual current.

22 Chapter 3 Temperature Controller Operation

3.4.2.4 Gain

The Gain function controls two parameters of the hybrid PI control loop;
proportional gain and integration time.

When the actual temperature and the set point are different, an error voltage is
generated. This error voltage is directly related to the difference in the actual and set
point temperatures. The error voltage is then amplified by the proportional gain.
This amplified error voltage controls the amount o f c urrent driven through the T EC.
The higher the gain, the more current will be driven for any given temperature
difference, with the maximum current being determined by the current limit.

The error voltage also drives an integrator. The integrator’s output also controls the
amount of curre nt being driven t hrough the TE C. The integr ator is an ampli fi er
whose gain is proportional to time. T he longer a given error voltage is present, the
more current will be driven through the TEC, with the maximum current being
determined by the current limit. The speed at which the integrator’s output increases
is the integration time, which can be “Slow” or “Fast”.

The allowed Gain values are: 0.2 Slow, 0.6 Slow, 1 Slow, 1 Fast, 2 Slow, 3 Fast, 5
Fast, 6 Slow, 10 Slow, 10 Fast, 20 Slow, 30 Fast, 50 Fast, 60 Slow, 100 Fast or 300
Fast. The number actually defines the proportional loop gain. The slow/fast suffix
indicates the speed at which the integrator’s output increases. The slow setting
allows for larger masses or greater distance between the sensor and the thermo­electric cooler by slowing the speed of the integrator.

Both the proportional gain and the integration time must be matched to the thermal
characteristics of the TE cooler and sensor. If the settings are incorrect, the
temperature set point will take an excessive amount of time to settle, or it will
oscillate around the set point and never settle.

The Gain setting depends on the type of T E cooler that you are using, but we can
suggest guidelines for selecting the proper ga in. Set the gain to 1 fast and increase it
until the actual temperature oscillates around the set temperature. Then reduce the
gain to the next lower value, without changing the suffix.

To read the Gain setting, go to the setup. The display will show the value of the Gain
setting. In Consta nt I

TE

mode the Gain setting has no effect.

3.4.2.5 Limits

3.4.2.5.1 TE Current Limit (Lim Ite)

This sets the maximum drive current the TEC will allow. This maximum applies to
all modes (constant I

TE

/R/T).

Chapter 3 Temperature Controller Operation 23

3.4.2.5.2 Temperature Limits (Lim Th and Lim Tl)

The TEC supports both a low and high temperature limit, and can be programmed to
turn the TEC output off in the event those limits are exceeded (default state). The
temperature limits are monitored regardless of the mode of the TEC. This has the
added sa fety feature of shutting down the TEC in Const I

TE

or Const R mode when
the temperature limit is exceeded (see TEC:OUTOFF command in Computer
Interfacing Manual for additional details).

Caution: these limits do not apply if the sensor type is set to “None.”

3.4.2.5.3 Resistance/Reference Limits (Li m Rh/ vhI/ih and Lim Rl/vlO/il)

Like the temp erature limits, the TEC also supports both a low and high
resistance/reference limit, and can be programmed to turn the TEC output off in the
event those limits are exceeded, although by default this is disabled. These limits are
monitored only while in Const R/v/i mode.

3.4.2.6 Tolerances (Tol Time and Tol Temp)

The

Tol Time

and

Tol Temp

elements are used for determining when the TEC is “in

tolerance,” where the actual temperature has stayed within

Tol Temp

of the set point

for at least

Tol Time

seconds. The

Tol Time

value is expressed in seconds, and can

range from 0.001 seconds to 50 seconds. The

Tol Temp

value is displayed in ºC
(the most common usage), and can range from 0.01 to 10.00. If at any time it goes
outside the tolerance range, the time restarts at zero.

As an example, if the

Tol Time

is set to 5 seconds, the

Tol Temp

is set to 0.2ºC,

and the temperature set point was 25.0ºC, the TEC would have to stay within

24.8ºC and 25.2ºC to be within tolerance. Out of tolerance is indicated by a

OutT

status field on the bottom of the TEC Main Screen.

3.4.2.7 Vpow, Ths, and Tamb

The three values monitor the operation of the TE drive section.

Vpow

is the supply

voltage, and can range from approximately 10V to 32V, depending on the TE load.

Ths

is the heatsink temperature, and will shutdown the unit if it exceeds 85ºC.

Tamb

is the internal ambient temperature of the unit.

3.4.2.8 C1, C2, C3, and Ro

See the section of each of the sensors for a description of how C1, C2, C3, and Ro
are used.

24 Chapter 3 Temperature Controller Operation

3.4.3 Thermistor and Thermistor Current Selection

3.4.3.1 Introduction

Choosing the ri ght sensing current depends on the range of tempera ture you want to
measure and the resolution you require at the highest measured temperature. To
correctly set the thermistor current you must understand how the thermistor and the
3150 interact.

3.4.3.2 Thermistor Range

Thermistors can span a wide temperature range, but their practical range is limited
by their non-linear resistance properties. As the sensed temperature increases, the
resistance of the thermistor decreases significantly and the thermistor resistance
changes less for an equivalent temperature change. Consider the temperature and
sensitivity figures below.

Temperature

Sensitivity

-20°C 5600 ohms/°C
25°C 439 ohms/°C
50°C 137 ohms/°C

In the 3150 the practical upper temperature limit is the temperature at which the
thermistor becomes insensitive to temperature changes. The maximum ADC input
voltage of the 3150 limits the lower end of the temperature range. Thermistor
resistance and voltage are related through Ohm's Law (V = I x R). T he 3150 supplies

current to the thermistor, either 10 µA or 100 µA , and as the resistance changes a
changing voltage signal is available to the thermistor inputs of the 3150. The 3150
will over-range when the input voltage exceeds about 5 Volts. Figure 12 graphically
shows the lower temperature and upper voltage limits for a typical 10 k Ohm
thermistor. The practical temperature ranges for a typical 10 K thermistor (a 10 K

thermistor has a resistance of 10 k Ohms at 25°C) are given in the table below.

Sensing Current

Temperature Range
10 µA -51 to 40°C
100 µA -10 to 100°C

Chapter 3 Temperature Controller Operation 25

Figure 12 - Thermistor Temperature Range

3.4.3.3 Temperature Resolution

You must also consider measurement resolution since the resolution decreases as the
thermistor temperature increases. The 3150 uses an A/D converter that has a

maximum resolution of about 0.763Ω in 10uA range. The microprocessor converts
this digital number to resistance, stores this resistance, then converts it to a
temperature using the Steinhart-Hart equation, and stores this temperature. A
temperature change of one degree centigrade will b e r epresented by a greater
resistance increase (and therefore more ADC counts) at lower temperatures because

of the non-linear resistance of the thermistor. Resolution figures for a typical 10 kΩ
thermistor are given below.

26 Chapter 3 Temperature Controller Operation

Temperature

Voltage at 10 µA Resolution

-20 °C 56.0 mV/°C 0.018 °C/mV
25 °C 4.4 mV/°C 0.230 °C/mV
50 °C 1.4 mV/°C 0.700 °C/mV

For this thermistor, a temperature change from -20°C to -19°C will be represented by
737 ADC counts (if supplied with 10µA). The same thermistor will only change
about 18 ADC counts from 49°C to 50°C.

3.4.3.4 Selecting Thermistor Current

To select the current setting for a typical 10 KΩ thermistor, determine the lowest
temperature you will need to sample and select the current according to the range

limits given above. If the temperature you want to sample is below -10°C you should
use the 10µA setting.

With the current set to 10µA the best resolution you will see will be a 1.0°C
temperature change. If, for example, the lower limit is 0°C you can choose either
setting, but there is a tradeoff in terms of resolution. If you need better than 0.1°C
measurement resolution you will have to change to 100µA.

If you need high resolution over a narrow range, for a very accurate measurement,
you can set the current setting for the maximum resolution. For example, at a high

temperature of 15°C, you require a measurement resolution of at least 0.05°C. This
resolution is within the range of either setting, but at the 10µA setting the resolution
is only 0.2°C while at the 100 µA setting the resolution is better than .05 °C.

Generally, it is best to use the 100µA setting for all measurements of -10°C or
greater with a 10 K thermistor.

3.4.3.5 Selecting Thermistors

The type of thermistor you choose will depend primarily on the operating
temperature range. These guidelines for selecting the range and resolution will apply
to any thermistor. 10 K thermistors are generally a good choice for most laser diode
applications where high stability is required near room temperatures. Similarly, 10 K
thermistors are often a good choice for cooling applications where you want to

operate at temperatures from -40°C to room temperature.

If you require a different temperature range or the accuracy you need can't be
achieved with either current setting, select another thermistor. Thermistor
temperature curves, supplied by the manufacturer, show the resistance versus
temperature range for many other thermistors. Contact a Newport application
engineer with your specific application.

Chapter 3 Temperature Controller Operation 27

3.4.3.6 The Steinhart-Hart Equation

The Steinhart-Hart equation is used to derive temperature from the non-linear
resistance of an NTC (Negative Temperature Coefficient) thermistor.

The following section contains an explanation of the Steinhart-Hart equation and the
values of these constants for some common thermistors.

Two terminal thermistors have a non-linear relationship between temperature and
resistance. The resistance versus temperature characteristics for a family of similar
thermistors is shown in Figure 13. It has been found empirically that the resistance
versus temperature relationship for most common negative temperature coefficient
(NTC) thermistors can be accurately modeled by a polynomial expansion relating the
logarithm of resistance to inverse temperature. The Steinhart-Hart equation is one
such expression and is given as follows:

1/T = C1 + C2 (Ln R) + C3 (Ln R)

3

(Eq. 1)

Where T is in KELVIN. To convert T to °C, subtract 273.15.

Once the three constants C1, C2, and C3 are accurately determined, only small errors
in the calculation of temperature over wide temperature ranges exist. Table 2 shows
the results of using the equation to fit the resistance versus temperature characteristic

of a common 10 kΩ thermistor. The equation will produce temperature calculation
errors of less than 0.01°C over the range -20 °C to 50 °C.

28 Chapter 3 Temperature Controller Operation

Figure 13 - Thermistor Resistance versus Temperature

---------Error T (°C)----------

R

1

T Actual Third Order

Fit. Eq. 1

2

96974 -20.00 -0.00
55298 -10.00 0.00
32651 0.00 -0.00
19904 10.00 -0.00
12494 20.00 -0.00
10000 25.00 0.00

8056 30.00 0.00
5325 40.00 0.00
3601 50.00 -0.00

Table 2 - Comparison of Curve Fitting Equations

The consta nt s C1, C2, and C3 are expressed in the form n.nnnn, simplifying entry
into the 3150.

1

Resistance of a BetaTHERM 10K3 thermistor.

2

Constants C1 = 1.1292 * 10-3, C2 = 2.3411 * 10-4, C3 = 0.8775 * 10-7

Chapter 3 Temperature Controller Operation 29

3.4.3.7 Table of Constants

We have listed some common thermistors and included the appropriate calibration
constants for the temperature range -20 °C to 50 °C in Table 3. The Model 3150, by

default, uses the BetaTHERM 10K3 thermistor values.

Manufacturer

C1 * 10-3 C2 * 10

-4

C2 * 10

-7

BetaTHERM 10K3 1.129241 2.341077 0.877547

BetaTHERM 0.1K1 1.942952 2.989769 3.504383
BetaTHERM 0.3K1 1.627660 2.933316 2.870016
BetaTHERM 1K2 1.373419 2.771785 1.999768
BetaTHERM 1K7 1.446659 2.682454 1.649916
BetaTHERM 2K3 1.498872 2.379047 1.066953
BetaTHERM 2.2K3 1.471388 2.376138 1.051058
BetaTHERM 3K3 1.405027 2.369386 1.012660
BetaTHERM 5K3 1.287450 2.357394 0.950520
BetaTHERM 10K3 1.129241 2.341077 0.877547
BetaTHERM 10K4 1.028444 2.392435 1.562216
BetaTHERM 30K5 0.933175 2.213978 1.263817
BetaTHERM 30K6 1.068981 2.120700 0.901954
BetaTHERM 50K6 0.965715 2.106840 0.858548
BetaTHERM 100K6 0.827111 2.088020 0.805620

Table 3 - Thermistor Constants

3.4.4 AD590 and LM335

3.4.4.1 General

The 3150 uses two constants (C1 and C2) for calibrating the two linear thermal
sensing devices, the AD590 and the LM335. C1 is used as the zero offset value, and
C2 is used as the slope or gain adjustment. Therefore, C1 has a nominal value of 0,
and C2 has a nominal value of 1 when using the AD590 or LM335. In order to
calibrate a linear sensor device, the sensor must be operated at an accurately known,

stable temperature. For example, the sensor may be calibrated at 0 °C if the sensor is
placed in ice water until its temperature is stable. A highly accurate temperature
probe, thermometer, environmental chamber, etc., may also be used to determine the
known temperature for calibration.

3.4.4.2 AD590 Sensor

The AD590 is a linear thermal sensor that acts as a current source. It produces a
current, i, which is directly proportional to absolute temperature, over its useful
range (-50 °C to + 150 °C). This nominal value can be expressed as:

i = 1 µA / K

where i is the nominal current produced by the AD590, and K is in Kelvin.

The 3150 uses i to determine the nominal temperature, T

n

, by the formula:

30 Chapter 3 Temperature Controller Operation

T

n

= (i/(1 µA / K) ) - 273.15

where T

n

is in °C.

The displayed temperature, T

d

= C1 + (C2 * Tn), is then computed, where C1 and C2

are the constants stored in the 3150 for the AD590. The AD590 grades of tolerance
vary, but typically without adjusting C1 and C2, the temperature accuracy is ±1°C

over its rated operating range. However, the AD590 is not perfectly linear, and even
with C1 accurately known there is a non-linear absolute temperature error associated
with the device. This non-linearity is shown in Figure 14, reprinted from Analog
Devices specifications, where the error associated with C1 is assumed to be zero.

Figure 14 - AD590 Nonlinearity

If a maximum absolute erro r of 0.8°C is tolerable, the one point calibration of C1
should be used. If a greater accuracy is desired, the two point method of determining
C1 and C2 should be used. Note however, the absolute error curve is non-linear,
therefore the constant C2 will vary for different measurement points.

3.4.4.3 LM335 Sensor

The LM335 is a linear thermal sensor that acts as a voltage source. It produces a
voltage, v, which is directly proportional to absolute temperature, over its useful

range (-40°C to + 100°C). This nominal value can be expressed as:

v = 10mV / K

where v is the voltage produced by the LM335 and K is Kelvin.

The 3150 uses v to determine the nominal temperature, T

n

, by the formula:

Chapter 3 Temperature Controller Operation 31

T

n

= (v / ( 10mV / K) ) - 273.15

where T

n

is in °C.

The temperature, T

d

, which is displayed by the 3150 is calculated as follows:

T

d

= C1 + (C2 * Tn)

where C1 and C2 are the constants stored in the 3150 for the LM335.

When the LM335 is calibrated to 25°C, C1 = 0 and C2 = 1, and the temperature
accuracy is typically ±0.5°C over the rated operating range. However, the LM335 is

not perfectly linear, and even with C1 accurately known there is a non-linear
absolute temperature error associated with the device. This non-linearity caused error

is typically ±0.3°C, with the error associated with C1 assumed to be zero.

If a maximu m absolute error of ±0.3°C can be tolerated, the one point calibration of
C1 should be used. If a greater accuracy is desired, the two point method of
determining C1 and C2 should be used. Note however, the absolute error associated
with the constant C2 may vary ove r different temperature ranges.

3.4.4.4 Determining C1 and C2 for the AD590 and LM335

The nominal values of C1 and C2 are 0 and 1, respectively, for both types of devices.
These values should be used initially for determining C1 and C2 in the methods
described below.

The One Point method is easiest, but it ignores the non-linearity of the device. It is
most useful when a high degree of temperature accuracy is not required.

The Two Point method can achieve a high degree of accuracy over a narrower
operating temperature range, but requires two accurate temperature measurements.

3.4.4.4.1 One Point Calibration Method

The calibration described in this section is independent of the calibration pro ced ure
described in sections 7.2.4 and 7.2.6. Those sections deal with the internal calibration
of the TEC, while the following calibration procedure is for calibrating the external
AD590 or LM335 sensor. For the most accurate possible results, both calibration
procedures should be performed.

The accuracy of this procedure depends on the accuracy of the externally measured
temperature. It is used to determine the zero offset of the device, and it assumes that
the gain (slope) is known.

1. Allow the 3150 to warm up for at least one hour. Select the desired
sensor type in the setup menu.

32 Chapter 3 Temperature Controller Operation

2. Set the C1 parameter to zero. Set the C2 parameter to 1.

3. Place the sensor at an accurately known and stable temperature, T

a

.
Connect the sensor to the 3150 for normal Constant temperature
operation. Allow the 3150 to stabilize at the known temperature, T

a

and

read the displayed temperature, T

d

.

4. Determine the new value of C1 from the formula:

C1 = T

a

- Td

and enter the new C1 value.

3.4.4.4.2 Two Point Calibrati on Method

The calibration described in this section is independent of the calibration procedure
described in sections 7.2.4 and 7.2.6. Those sections deal with the internal calibration
of the TEC, while the following calibration procedure is for calibrating the external
AD590 or LM335 sensor. For the most accurate possible results, both calibration
procedures should be performed.

The accuracy of this procedure depends on the accuracy of the externally measured
temperature. It is used to determine the zero offset of the device and the gain (slope).

1. Allow the 3150 to warm up for at least one hour. Select the desired
sensor type in the setup menu.

2. Set the C1 parameter to zero. Set the C2 parameter to 1.

3. Place the sensor at an accurately known and stable temperature, T

a1

.
Connect the sensor to the 3150 for normal Constant temperature
operation. Allow the 3150 to stabilize at the known temperature, T

a1

and read the displayed temperature, T

d1

. Record these values.

4. Repeat Step 3 for another known temperature, T

a2

, and the

corresponding displayed temperature, T

d2

. The two known temperatures
should at the bounds of the intended operating range. For best results,
make the range between T

a1

and Ta2 as narrow as possible.

5. Determine the new value of C1 and C2 from the following calculations.

C2 = (T

a1

- Ta2) / (Td1 - Td2), and

C1 = T

a1

- (Td1* C2)

6. Enter the new C1 and C2 values.

Chapter 3 Temperature Controller Operation 33

3.4.5 RTD Sensors

The following equation is used in temperature to resistance conversions:

R

T

= R0 [1 + C1 x T - C2 x T2 - C3 x (T-100) x T3) for T < 0°C

R

T

= R0 [1 + C1 x T - C2 x T2) for T >= 0°C

where: R

T

is the resistance in Ω at temperature T.

T is the temperature in °C.

3.4.5.1 RTD Constants

The constants entered for an RTD depend on the type of curve it has. Table 4 shows
three standard types.

Curve TCR

(

ΩΩΩΩ/ΩΩΩΩ/°°°°

C)

C1 C2 C3 R0

Laboratory .003926 3.9848x10-3 -0.58700x10-6 4.0000x10

-12

100.00

US .003910 3.9692x10

-3

-0.58495x10-6 -4.2325x10

-12

100.00

European .003850 3.9080x10

-3

-0.58019x10-6 -4.2735x10

-12

100.00

Table 4 - RTD Constants

The Ro constant also applies for RTD sensors. It is nominally 100.00 Ω, but can be
varied from 95.00 Ω to 105.00 Ω.

35

CHAPTER 6

4

Principles of Operation

4.1 Introduction

A functional block diagram of the 3150 is shown in Figure 15. In each of the
following sections there are functional block diagrams for the various circuit boards
of the 3150.

GPIB/RS232

Front Panel

Microprocessor

Parallel Bus

Serial Bus

TEC

Optical

Interface

TEC

Control

TEC

Output

TEC

Main

Power

Supply

Analog

Supply

Switching

Supply

Power Supplies

TEC

TEC

Figure 15 - 3150 Block Diagram

36 Chapter 4 Principles of Operation

4.2 TEC Controller Theory of Operation

Figure 16 shows the functionality of the TEC. The following sections detail the
theory of operation for each of the blocks in Figure 16.

O ptically

Isolated

Serial Bus

Bipolar
Output

Stage

Limit DAC

Proportional Amp

Inte g r a l A mp

Differential

Sensor

Select and

TEC

Sensor Lines

A/D

Converter

Limit Se t P o in t

PI Loop

Set

Set Point

DAC

Actual

Heat/Cool Lines

Current

Amps

Amp

To M icroprocessor

Voltage

Figure 16 - TEC Board Diagram

4.2.1 TEC Interface

The TEC interface provides optically isolated serial communications between the
TEC board and the microprocessor. Control signals are passed to the TEC board to
set the TEC board status, current limit, and temperature set points. Instructions and
data are sent over the serial interface to the optical barrier. Status and data are
serially passed back to the microprocessor.

4.2.2 Limit DAC

The microprocessor loads the digitally stored current limit value into the current
limit 12-bit DAC. The Limit DAC converts the digital limit signal from the
microprocessor to a voltage which becomes the limit voltage for the Bipolar Output
Stage. The current limit value is updated at power-up, at a "bin" recall, and whenever
the LIM I

TE

value is changed.

Chapter 4 Principles of Operation 37

4.2.3 Set Point DAC

The microprocessor loads the digitally stored temperature or current set point value
into the set point 16-bit DAC. The Set Point DAC converts a digital set point signal
from the microprocessor to a voltage which becomes the set point input to the PI
control loop. The TEC set point value is updated at power-up, at a "bin" recall, and
whenever a TEC set point value is changed.

4.2.4 A/D Converter

The 16-bit A/D converter measures the sensor voltage, TE current, and TE voltage.
The sensor measurement is used by the microprocessor in the calculation of
temperature or thermistor resistance. The current measurement is used for the I

TE

value and the voltage measurement is needed for V

TE

.

4.2.5 Sensor Select

Sensor selection is accomplished in the Sensor Select block of the TEC board.
Precision 100µA and 10µA current sources may be selected for thermistor control.

RTD, LM335 and AD590 IC temperature sensors may also be selected. The AD590
has a +5 VDC bias voltage, the LM335 has a 1 mA bias current, and the RTD has a
precision 1 mA current source.

The output of the Sensor Select block of the TEC board is a voltage which is
proportional to the actual temperature. This voltage is fed to the A/D converter
which provides a digital measurement to the microprocessor, and to the PI control
loop to close the feedback loop when temperature is being controlled.

4.2.6 Difference Amplifier

A differential amp provides a difference signal to the PI control. This signal is the
difference between set temperature and actual temperature voltage.

4.2.7 Proportional Amplifier

The Proportional amplifier is part of a digitally controlled gain stage consisting of
the analog switches and their associated resistors. The analog switches vary the ratio
of resistance in the feedback circuit to change the gain. The gain setting determines
how fast the TEC reaches the set point temperature and how quickly it settles to this
temperature.

4.2.8 Integrator

The signal from the difference amplifier is sent to an integrator which reduces the
difference between the set point temperature and the actual temperature to zero,
regardless of the gain setting. An analog switch discharges the integrating capacitor
whenever integration is not required to prevent unnecessary difference signal
integration.

38 Chapter 4 Principles of Operation

4.2.9 Bipolar Output Stage

The Bipolar Output Stage consists of circuits which limit the TEC output, sense the
TEC output polarity, sense voltage and current limit conditions, as well as supply the
bipolar TEC output. The following sections discuss these functions of the Bipolar
Output Stage.

4.2.9.1 Current Limiting

The output of the proportional amplifier and integrator together form the control
signal. Output current limiting is effected by bounding the control signal so that it is
always less than the limit current. The limit current is set with the front panel
controls or through the GPIB. The bipolar current limit levels are established by the
output of the current Limit DAC.

4.2.9.2 Current Limit Condition Sensing

Comparators sense the output to determine when output current limiting is occurring.
When this condition occurs, the I Limit signal is sent to the microprocessor.

4.2.9.3 Voltage Controlled Current Source

The bounded output control signal is applied to an amplifier. This amplifier and the
current sensing amplifier form the o ut put voltage controlled current source. The
output of this stage directly drives the externally connected TE cooler.

4.2.9.4 Voltage Limit Condition Sensing

Comparators sense the output to determine when the TEC output compliance voltage
limiting is occurring. This condition occurs whenever the TEC output is open or
connected to a high resistance. If this condition occurs, the V Limit error signal is
passed to the microprocessor.

4.2.10 TEC Control Modes

The 3150 provides three control modes for operation, constant T (temperature),
constant R (resistance, voltage, or current), and constant I

TE

(current) modes. Each

of these modes is discussed in the following sections.

4.2.10.1 T Mode

In constant T mode the TEC is driven to the set point temperature. This temperature
is monitored by the sensor in the TEC. In the case of a thermistor sensor, the
thermistor's resistance is used to determine TEC's temperature by using the
Steinhart-Hart conversion equation. The resistance is determined by measuring the

voltage across the thermistor (with a known current of 10µA or 100µA). The I

TE

current is also measured and saved. The TEC's output current is sensed across a
resistor and the voltage is converted to an I

TE

current value. VTE is also measured.

Chapter 4 Principles of Operation 39

When an LM335 sensor is used, a two-point conversion equation is used to
determine the temperature. Its voltage is measured as well as the I

TE

current and VTE

voltage.

When an AD590 sensor is used, another two-point conversion equation is used to
determine the temperature. Its reference current is sensed across a resister, and this
voltage is measured. I

TE

and VTE are also measured.

4.2.10.2 R Mode

In constant R mode, the TEC is driven to the set point resistance, voltage, or current.
This resistance, voltage, or current is measured. I

TE

and VTE are also measured.

4.2.10.3 ITE Mode

In constant ITE mode, the TEC is driven with a constant current, at the ITE set point
value. The I

TE

current is sensed across a resistor and the voltage is converted to ITE

current.

40 Chapter 4 Principles of Operation

4.3 Microprocessor Board

The Microprocessor Board contains the microprocessor, memory, the serial interface
to the TEC, front panel interface, and circuitry that saves the state of the 3150 at
power down. The block diagram of the Microprocessor Board is shown in Figure

17.

Power Failure

and Watch Dog

Failure Detection

80188 EB

Microprocessor

RAM ROM

EEPROM

Data Bus

Address Bus

TEC

Interface

Front Panel

Interface

RS 232

Interface

To Front Panel RS 232 Ports To TEC

Power Fail/Reset

Watchdog Reset

Figure 17 - Microprocessor Board Block Diagram

4.3.1 Microprocessor

The 3150 uses a CMOS 80188EB microprocessor to control its internal operations.
The 3150 provides a fail-safe timer which generates a reset in the event of a
malfunction. A 1 Hz watch-dog pulse is normally present. If for any reason this
clock pulse fails to appear it will reset the 3150.

Chapter 4 Principles of Operation 41

4.3.2 Memory

The 3150 uses three types of memory. RAM memory is retained only while power
is applied to the unit. ROM memory contains the firmware. The third type of
memory is electrically erasable programmable memo ry: EEPROM.

EEPROM stores calibration constants and other data which must be retained even
when power is removed from the unit, and does not require battery backup.
Examples of data stored in this memory include the TEC parameters and calibration
constants.

4.3.3 Serial Interface

The 80188 communicates with the TEC controller via a serial bus. Parallel data
from the microprocessor is converted to bi-directional serial data. Also provided is
the RS-232 communication.

4.3.4 Front Panel Interface

Provides parallel communication with the front panel.

4.3.5 GPIB Interface

Provides parallel communication with the GPIB port.

4.4 Power Supplies

AC power is suppl i ed through the rear panel i nput power connector which provides
in-line transient protection and RF filtering. The input power connector contains the
fuses and the switch to select series or parallel connection of the transformer
primaries for operation at 100 VAC, 120 VAC, 220 VAC, or 240 VAC.

4.4.1 TEC Power Supplies

There are two separate power supplies for the TEC. The linear supply provides
analog and digital circuit power. The OEM switching supply provides the power to
drive the TEC.

Rectifiers

and Filters

Regulators

Switching

Supply

Transformer

TEC Output

Drive

Main

Supply

Power Entry

Module

Rectifiers

and Filters

Regulators

TEC

Supply

Figure 18 - Power Supply B lock Diagram

42 Chapter 4 Principles of Operation

4.4.2 Main Supply

This supply provides digital circuit power for all functions except the TEC. It also
provides fan power.

43

CHAPTER 5

5

Tips and Techniques

5.1 Introduction

This chapter is intended to further explain specific operational details of the Model
3150, as well as provide application examples.

5.2 TEC Limits

The TEC maintains several limits that control the operation of the unit. There are a
total of five limits: I

TE

current limit, high temperature limit, low temperature limit,
high resistance/LM335 voltage/AD590 current limit (R/v/i), and low
resistance/LM335 voltage/AD590 current limit.

Through the rest of this section, the resistanc e/LM335 voltage/AD590 current mode
is collectively referred to as R mode, while the resistance/LM335 voltage/AD590
current limits are collectively referred to as the R limits.

I

TE

Limit

The I

TE

limit controls the maximum amount of current the TEC will drive while in
any mode. The limit applies to both the positive and negative current drive. In
temperature and R modes, it limits the amount of current that can be driven when
controlling to the set point. In I

TE

mode, it limits the set point to less than or equal to

the limit. Unlike the temperature and R limits, the I

TE

limit is controlled by hardware

for immediate response.

Temperature Limits

The high and low temperature limits define the operating temperature range of the
TEC, and are monitored while in any mode. The only case where temperature is not
monitored is when a sensor type of “None” is selected. Temperature checking for
high and low limits is done once per second, and when the system detects that a high
or low temperature limit has been exceeded, it will shutdown the TEC output. Note,
however, that cle aring the appropriate bits in the TEC O UTOFF register through the
GPIB or RS-232 interface can disable this automatic shutdown. The factory default
is to shutdown the TEC on a temperature limit.

Resistance, LM335 Voltage, and AD590 Current Limits (R Limits)

In addition to temperature and current limits, the TEC also supports limits based on
sensor values. R l imits are monitored only when in the R mode, although as
mentioned above, the T limits are monitored in any mode. R checking for high and
low limits is done once per second. However, unlike a temperature limit, and when
the system detects that a high or low R limit has been exceeded, by default it will not
shutdown the TEC output. Note, however, that setting the appropriate bit in the TEC

44 Chapter 5 Tips and Techniques

OUTOFF regist er through the GP IB or RS-232 interface can enable this automatic
shutdown. The factory default is to not shutdown the TEC on a R limit.

How a Sensor Change Affects R Values

Each time the sensor is changed, the old R limits and set point no longer apply to the
new sensor. The 3150 calculates the new values for the upper and lower R limits and
set point based on the temperature limits and set point. After the R values are
initialized, changing the temperature limits or set point will not affect the
corresponding R values until the next time the sensor type is changed.

45

CHAPTER 6

6

Maintenance

6.1 Introduction

There are no user serviceable parts inside. Do not attempt to remove the cover.

6.2 Fuse Replacement

The fuses are accessible on the back panel of the 3150. Before replacing a fuse, turn
power off and disconnect the line cord. Use only the fuses indicated below.

Line Volta ge

Fuse Replacement
90-110 VAC 6 Amp, 3 AG, Slo-Blo, 250V
108-132 VAC 6 Amp, 3 AG, Slo-Blo, 250V
198-242 VAC 6 Amp, 3 AG, Slo-Blo, 250V
216-250 VAC 6 Amp, 3 AG, Slo-Blo, 250V

6.3 Cleaning

Use mild soap solution on a damp but not wet cloth. Disconnect AC power before
cleaning.

47

CHAPTER 7

7 Calibration

7.1 Calibration Overview

The 3150 performs an automatic calibration on power-up. This removes the majority
of calibration error. However, if it is desired to completely calibrate the system, the
following procedures will do so.

All calibrations are done with the case closed. The instrument is calibrated by
changing the internally stored digital calibration constants.

All calibrations may be performed locally or remotely.

7.1.1 Environmental Conditions

Calibrate this instrument under laboratory conditions. We recommend calibration at
25°C ± 1.0°C. When necessary, however, the 3150 may be calibrated at its intended
use temperature if this is within the specified operating temperature range of 0°C to
40°C.

7.1.2 Warm-Up

The 3150 should be allowed to warm up for at least 1 hour before calibration.

7.2 TEC Calibration

7.2.1 Recommended Equipment

Recommended test equipment for calibrating the TEC is listed in Table 5.
Equipment other than that shown in the table may be used if the specifications meet
or exceed those listed.

48 Chapter 7 Calibration

Description

Mfg./Model Specification

DMM HP34401A

DC Amps @ 1.0 A): ±1%
Resistance (@ 10 ohms): 0.02%

Resistors Metal Film

20 kΩ for 100µA calibration
200 kΩ for 10µA calibration
3 kΩ for LM335 sensor calibration
16 kΩ for AD590 sensor calibration
100 Ω for RTD sensor calibration

Resistor High Power

1 Ω, 50 W, for current calibration

Connector D-sub 15-pin male

Table 5 - Recommended Test Equipment

7.2.2 Local Operation Thermistor Calibration

a. Measure and record the exact resistance of your metal film resistor. Use

nominal values of 20 kΩ for the 100µA setting, and 200 kΩ for the
10µA setting. With the TEC output off, connect the metal film resistor
to the sensor input of the TEC.

b. Press the

Setup

soft key and select the appropriate thermistor (10µA or

100µA) as the sensor type.

c. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

Sensor

soft key. Follow the on-screen instructions to
complete the calibration. The calibration can be terminated without
affecting the stored constants if the

Term

soft key is pressed at any

point prior to completing the calibration.

7.2.3 Remote Operation Thermistor Calibration

a. Measure and record the exact resistance of your metal film resistor. Use

nominal values of 20 kΩ for the 100µA setting, and 200 kΩ for the
10µA setting. With the TEC output off, connect the metal film resistor
to the sensor input of the TEC Output connector.

b. Send

TEC:SENS 1

100µA thermistor, or

TEC:SENS 2

for the 1 0µA

thermistor, followed by the

TEC:CAL:SEN

to enter sensor calibration

mode.

Chapter 7 Calibration 49

The 3150 will be ready to receive the resistance when, after a

TEC:CAL:SEN?

query is sent, a “1” is returned.

c. Input the actual resistance of the metal film resistor, in kΩ, (as an <nrf

value>) via the

TEC:R <nrf value>

command.

If, at any time prior to

TEC:R,

a command other than

TEC:R

or

TEC:R?

is sent to the 3150, the 3150 will cancel the calibration mode

and then process the command(s).

Once the

TEC:R

value is sent, the

OPC?

que ry may be used to
determine when the calibration is completed. The operation complete
flag (bit 0 of the Standard Event Status Register) may be used to trigger
an interrupt. This type of interrupt is enabled by setting bit 0 of the
Service Request Enable register and using the

*OPC

command.

7.2.4 Local Operation AD590 Sensor Calibration

a. With the TEC output off, connect a precision 16 kΩ metal film resistor

and a precision ammeter in series at the sensor input of the TEC Output
connector.

b. Press the

Setup

soft key and select the AD590 as the Sensor Type.

c. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

Sensor

soft key. Follow the on-screen instructions to
complete the calibration. The calibration can be terminated without
affecting the stored constants if the

Term

soft key is pressed at any

point prior to completing the calibration.

7.2.5 Remote Operation AD590 Sensor Calibration

a. With the TEC output off, connect a precision 16 kΩ metal film resistor

and a precision ammeter in series at the sensor input of the TEC Output
connector.

b. Enter the

TEC:SEN 4

and

TEC:CAL:SEN

to select the AD590 sensor

and enter sensor calibration mode.

The 3150 will be ready to receive the current value when, after a

TEC:CAL:SEN?

query is sent, the response from the 3150 is “1”.

c. Input the actual current measured, in µA, by the external ammeter (as

an <nrf value>) via the

TEC:R <nrf value>

command.

50 Chapter 7 Calibration

If, at any time prior to

TEC:R,

a command other than

TEC:R

or

TEC:R?

is sent to the 3150, the 3150 will cancel the calibration mode

and then process the command(s).

Once the

TEC:R

value is sent, the

OPC?

que ry may be used to
determine when the calibration is completed. The operation complete
flag (bit 0 of the Standard Event Status Register) may be used to trigger
an interrupt. This type of interrupt is enabled by setting bit 0 of the
Service Request Enable register and using the

*OPC

command.

7.2.6 Local Operation LM335 Sensor Calibration

a. Use a 3 kΩ metal film resistor. With the TEC output off, connect the

metal film resistor in parallel with a precision voltmeter to the sensor
input of the TEC Output connector.

b. Press the

Setup

soft key and select the LM335 as the Sensor Type.

c. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

Sensor

soft key. Follow the on-screen instructions to
complete the calibration. The calibration can be terminated without
affecting the stored constants if the

Term

soft key is pressed at any

point prior to completing the calibration.

7.2.7 Remote Operation LM335 Sensor Calibration

a. With the TEC output off, connect a 3 kΩ metal film resistor and a

precision voltmeter in parallel at the sensor input of the TEC Output
connector.

b. Enter the

TEC:SEN 3

and

TEC:CAL:SEN

to select the LM335 sensor

and enter sensor calibration mode.

The 3150 will be ready to receive the voltage value when, after a

TEC:CAL:SEN?

query is sent, the response from the 3150 is "1".

c. Input the actual voltage, in mV, measured by the external voltmeter (as

an <nrf value>) via the

TEC:R <nrf value>

command.

If, at any time prior to

TEC:R,

a command other than

TEC:R

or

TEC:R?

is sent to the 3150, the 3150 will cancel the calibration mode

and then process the command(s).

Once the

TEC:R

value is sent, the

OPC?

que ry may be used to
determine when the calibration is completed. The operation complete
flag (bit 0 of the Standard Event Status Register) may be used to trigger

Chapter 7 Calibration 51

an interrupt. This type of interrupt is enabled by setting bit 0 of the
Service Request Enable register and using the

*OPC

command.

7.2.8 Local Operation RTD Calibration

a. Measure and record the exact resistance of your 100Ω metal film

resistor. With the TEC output off, connect the metal film resistor to the
sensor input of the TEC Output connector.

b. Press the

Setup

soft key and select the RTD as the Sensor Type.

c. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

Sensor

soft key. Follow the on-screen instructions to
complete the calibration. The calibration can be terminated without
affecting the stored constants if the

Term

soft key is pressed at any

point prior to completing the calibration.

7.2.9 Remote Operation RTD Calibration

a. Measure and record the exact resistance of your 100Ω metal film

resistor. With the TEC output off, connect the metal film resistor to the
sensor input of the TEC Output connector.

b. Send

TEC:SENS 5

to select the RTD sensor, followed by the

TEC:CAL:SEN

to enter sensor calibration mode.

The 3150 will be ready to receive the resistance when, after a

TEC:CAL:SEN?

query is sent, a “1” is returned.

c. Input the actual resistance, in ohms, of the metal film resistor (as an

<nrf value>) via the

TEC:R <nrf value>

command.

If, at any time prior to

TEC:R,

a command other than

TEC:R

or

TEC:R?

is sent to the 3150, the 3150 will cancel the calibration mode

and then process the command(s).

Once the

TEC:R

value is sent, the

OPC?

que ry may be used to
determine when the calibration is completed. The operation complete
flag (bit 0 of the Standard Event Status Register) may be used to trigger
an interrupt. This type of interrupt is enabled by setting bit 0 of the
Service Request Enable register and using the

*OPC

command.

7.2.10 RTD Lead Resistance Calibration (Offset Null)

Because the RTD sensor reflects changes in temperature with small changes in
resistance, even a small lead resista nc e (resistance c aused by the wire running

52 Chapter 7 Calibration

between the TEC and the RTD sensor) can cause significant temperature offset. The
lead resistance may be taken out of the RTD reading as follows:

a. With the TEC output off, short the sensor wires as close to the RTD

sensor as possible.

b. Press the

Setup

soft key and select the RTD as the Sensor Type.

c. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

RTD Null

soft key. Follow the on-screen instructions to
complete the calibration. The calibration can be terminated without
affecting the stored constants if the

Term

soft key is pressed at any

point prior to completing the calibration.

7.2.11 Local Operation ITE Current Calibration

The following procedure is for calibrating the ITE constant current source for both
polarities of current.

a. With the output off, connect a 1Ω, 50W resistor and a calibrated

ammeter in series across the output terminals. If an ammeter with the
appropriate current ratings is unavailable, connect a 1Ω, 50W resistor

across the output terminals and use a calibrated DMM to measure the
voltage across the resistor. Calculate the current in the following steps
by using Ohm's Law:

I = V / R

where V is the measured voltage across the resistor, and R is the

measured load resistance.

b. Go to the calibration display by first pressing the

MENU

button, then

the

Config

soft key, then the

Cal

soft key. At the calibration screen,

press the

I

TE

soft key. Follow the on-screen instructions to complete
the calibration. The calibration can be terminated without affecting the
stored constants if the

Term

soft key is pressed at any point prior to

completing the calibration.

7.2.12 Remote Operation ITE Current Calibration

a. With the output off, connect a 1Ω, 50W resistor and a calibrated

ammeter in series across the output terminals. If an ammeter with the
appropriate current ratings is unavailable, connect a 1Ω, 50W resistor

across the output terminals and use a calibrated DMM to measure the
voltage across the resistor. Calculate the current in the following steps
by using Ohm's Law:

Chapter 7 Calibration 53

I = V / R

where V is the measured voltage across the resistor, and R is the

measured load resistance.

b. Send

TEC:CAL:ITE

to enter I

TE

calibration mode.

The TEC will be placed in I

TE

mode, limit set to 50% of full scale plus

100 mA, and the I

TE

set point set to 50% of full scale.

The 3150 will be ready to receive the first measured current value

when, after a

TEC:CAL:ITE?

query is sent, a “1” is returned.

c. Input the actual current (as an <nrf value>) via the

TEC:ITE <nrf

value>

command. The 3150 will then drive the current to 25% of the

initial set point.

The 3150 will be ready to receive the second measured current value

when, after a

TEC:CAL:ITE?

query is sent, a “1” is returned.

d. Input the second actual current (as an <nrf value>) via the

TEC:ITE

<nrf value>

command. The 3150 will then drive the current to the

negative current value of the initial set point.

The 3150 will be ready to receive the third measured current value

when, after a

TEC:CAL:ITE?

query is sent, a “1” is returned.

e. Input the third actual current (as an <nrf value>) via the

TEC:ITE

<nrf value>

command. The 3150 will then drive the current to 25% of

the negative current value of the initial set point.

The 3150 will be ready to receive the fourth measured current value

when, after a

TEC:CAL:ITE?

query is sent, a “1” is returned.

f. Input the fourth actual current (as an <nrf value>) via the

TEC:ITE

<nrf value>

command.

If, at any time prior to the last

TEC:ITE,

a command other than

TEC:ITE

or

TEC:ITE?

is sent to the 3150, the 3150 will cancel the

calibration mode and then process the command(s).

Once the

TEC:ITE

value is sent, the

OPC?

que ry may be used to
determine when the calibration is completed. The operation complete
flag (bit 0 of the Standard Event Status Register) may be used to trigger
an interrupt. This type of interrupt is enabled by setting bit 0 of the
Service Request Enable register and using the

*OPC

command.

55

CHAPTER 8

8

Factory Service

8.1 Introduction

This section contains info rmation regar ding obtaining factory service for the Model

3150. The user should not attempt any maintenance or service of this instrument
and/or accessories beyond the procedures given in chapters 6 and 7. Any problems
which cannot be resolved using the guidelines listed in chapters 6 and 7 should be
referred to Newport Corporation factory service personnel. Contact Newport
Corporation or your Newport representative for assistance.

8.2 Obtaining Service

To obtain information concerning factory service, contact Newport Corporation or
your Newport representative. Please have the following information available:

1. Instrument model number (On front panel)

2. Instrument seri al number (On rea r panel)

3. Description of the problem.

If the instrument is to be returned to Newport Corporation, you will be given a
Return Materials Authorization (RMA) number, which you should reference in your
shipping documents as well as clearly marked on the outside of the shipping
container.

Please fill out the service form, located on the following page, and have the information ready when
contacting Newport Corporation. Return the completed service form with the instrument.

Service Form

Newport Corporation

USA Office: 949/863-3144
FAX: [phone]

Name

RETURN AUTHORIZATION #

Company

(Please obtain prior to return of item)
Address
Country

Date
P.O. Number

Phone Number

Item(s) being returned:

Model #

Serial #
Description
Reason for return of goods (please list any specific problems)

List all control settings and describe problem

(Attach additional sheets as necessary)

Show a block diagram on the backside of this page of your measurement system including all
instruments connected (whether power is turned on or not). Describe signal source. If source is laser,
describe output mode, peak power, pulse width, and repetition rate.

Where is measurement being performed?

(factory, controlled laboratory, out-of-doors, etc.)
What power line voltage is used?

Variation?

Frequency?

Ambient Temperature?
Any additional information. (If special modifications have been made by the user, please describe
below)

59

CHAPTER 9

9

Error Messages

9.1 Introduction

Error messages may appear on the display when error conditions occur in the
respective functions of the 3150. For example, a current limit error in the TEC will
be displayed.

In remote operation, the current error list can be read by issuing the "ERR?" query.
When this is done, a string will be returned containing all of the error messages
which are currently in the error message queue.

The errors codes are numerically divided into areas of operation as shown below.

Error Code Range

Area of Operation

E-001 to E-099 Internal Program Errors
E-100 to E-199 Parser Errors
E-200 to E-299 Execution Control Errors
E-300 to E-399 GPIB/RS232 Errors
E-400 to E-499 TEC Control Errors

Table 6 contains all of the error messages which may be generated by the 3150. Not
all of these messages may be displayed. Some refer to GPIB activities only, for
example.

Table 6 - Error Codes

Error Code

Explanation

E-001 Memory allocation failure.
E-002 Floating point error

E-104 Numeric type not defined.
E-106 Digit expected.
E-107 Digit not expected.
E-115 Identifier not valid.
E-116 Parser syntax error, character was not expected.
E-126 Too few or too many program data elements.

E-201 Value out of range.
E-214 Length exceeds maximum.
E-217 Attempted to recall a bin from a unsaved position.
E-218 Additional link could not be added to the link table because the

link table is already full.

E-301 A response message was ready, but controller failed to read it.
E-302 3150 is talker, but controller didn't read entire message.

60 Chapter 9 Error Messages

Error Code

Explanation

E-303 Input buffer overflow
E-304 Output buffer overflow
E-305 Parser buffer overflow

E-402 Sensor open disabled output.
E-403 TEC open disabled output.
E-404 TEC Current limit disabled output.
E-405 TEC Voltage limit disabled output.
E-406 TEC resistance/reference limit disabled output
E-407 TEC high temperature limit disabled output.
E-409 Sensor change disabled output.
E-410 TEC out of tolerance disabled output.
E-415 Sensor short disabled output.
E-416 Incorrect Configuration for Calibration Sequence to start.
E-417 TEC output must be on to begin calibration.
E-418 TEC C1, C2, or C3 constants are bad, all set to default values.
E-419 Mode change disabled output.
E-431 TEC link condition forced output on
E-432 TEC link condition forced output off

E-900 Calculation Error shutdown output
E-901 System over temperature shutdown all outputs
E-903 Loading of a saved bin shutdown TEC output

61

CHAPTER 10

10 Specifications

10.1 Temperature Controller Specifications

Specifications 3150
TEC Output

Maximum Current / Voltage 15 Amps at 23 Volts or 12.5 Amps at 28 Volts
Maximum Power 350 Watts
TE Current Resolution (mA) 0.458
TE Current Accuracy (mA) ± (3 % set point + 50 mA)

Current Limit

Range 0 to 15 Amps
Accuracy ± 150 mA

Ripple/Noise (rms) < 10 mA
Short Term Stability (1 hour) < 0.0005 °C
Long Term Stability (24 hour) < 0.001 °C
Temperature Coeffi cient (°C/°C) < 0.05

Display
Range

Temperature -100.00°C to +240.00°C
Resistance (10 µA) 0.01 kΩ to 495.000 kΩ
Resistance (100 µA) 0.001 kΩ to 49.500 kΩ

Resistance (RTD) 20 Ω to 192 Ω
LM335 Voltage 2331 mV to 3731 mV
AD590 Current 248.15 µA to 378.15 µA
TE Current

±

15.00 Amps

TE Voltage 0.0 to 30.0 Volts

Resolution

Temperature 0.01°C
Resistance (10 µA) 10 Ω
Resistance (100 µA) 1 Ω
Resistance (RTD) 0.01 Ω
LM335 Voltage 0.1 mV
AD590 Current 0.01 µA
TE Current 10 mA
TE Voltage 0.1 Volts

Accuracy

3

Temperature ± 0.1 °C
Resistance (10 µA) ± (0.04% + 16 Ω)
Resistance (100 µA) ± (0.05% + 8 Ω)
Resistance (RTD) ± (0.03% + 50 mΩ)
LM335 Voltage ± (0.09% + 1 m V)
AD590 Current ± (0.005% + 0.5 uA)
TE Current ± (0.25% + 30 mA)
TE Voltage ± (0.005% + 100 mV)

3

± (% of reading + fixed error)

62 Chapter 10 Specifications

Temperature Sensors Thermistors AD590 LM335 RTD (100

ΩΩΩΩ

)

Temp Control Resolution 0.01 °C 0.01 °C 0.01 °C 0.01 °C
Temp Control Accuracy ± 0.05 °C ± 0.05 °C ± 0.05 °C ± 0.05 °C

4

Sensor Bias Current or Voltage 10 µ A/100 µA +5 Volts 1 mA 1 mA

Temperature Calibration

Thermistor 1/T = (C1 x 10-3) + (C2 x 10-4)(ln R) + (C3 x 10-7)(ln R)3
AD590 T = C1 + C2 x (I

AD590

/1µA/K - 273.15)

LM335 T = C1 + C2 x (V

LM335

/10mV/K - 273.15)

Pt RTD R

T

= Ro [ 1 + C1 * T + C2 * T2] ; T ≥ 0 °C,

R

T

= Ro [ 1 + C1 * T + C2 * T2 + C3 * T3 * (T - 100)] ; T < 0 °C

Ro = resistance at 0 °C where, Ro=100Ω for a 100Ω Pt RTD.

10.2 General Specifications

Display
Type LCD character display, 4 lines by 20 characters
Back Lighting Green LED
Controls Brightness and Contrast (contrast optimizes viewing angle)
Channel Active Green LDD LED indicates that temperature controller output is on.
Output Connectors
Temperature Controller (TEC) High Power 7W2 female D-sub
Chassis Ground 4 mm Banana Jack
GPIB Connector 24 pin IEEE-488
RS232 Connector 9-pin male D-sub

Power Requirements 90 to 132V, 6A Max.; 198 to 250V, 3A Max. (user selectable), 50 to 60 Hz
Size (H x W x D) 86 mm x 356 mm x 356 mm (3.5 " x 14" x 14")
Mainframe Weight 5.9 kg (14 lbs.)
Operating Temperature 0 to 40°C, < 80% relative humidity non-condensing
Storage Temperature -20°C to 60°C, < 90% relative humidity non-condensing
Isolation TEC electrically isolated with respect to earth ground.

In accordance with ongoing efforts to continuously improve our products, Newport
Corporation reserves the right to modify product specifications without notice and
without liability for such changes.

4

Accuracy is with lead wire resistance calibrated out.