Thornton 550 Series, 550-HT, 550-SX Instruction Manual

THORNTON

Leading Pure Water Analytics

550

Total Organic Carbon

Analyzer

Instruction Manual

Part No. 84428

IMPORTANT SAFETY INFORMATION

Please read and observe the following:
INSTALLATION: This instrument must be installed by trained instrumentation personnel in accordance

with relevant local codes and instructions in this manual. Observe all instrument specifications and ratings.
SHOCK HAZARD: Make sure power to all wires is tur ned off befor e proceeding with installation or service

of this instrument. High voltage may be present on the input power and relay wires.
RELAY CONTROL ACTION: Relays will always de-energize on loss of power, equivalent to normal state,

regardless of relay state setting for powered operation. Configure any control system using these relays
with fail-safe logic accordingly.

PROCESS UPSETS: Because process safety conditions may depend on consistent operation of this
instrument, tak e appropriate action to maintain conditions dur ing sensor cleaning, replacem ent or sensor
or instrument calibration.

This manual includes safety information with the following designations and formats:

WARNING: POTENTIAL FOR PERSONAL INJURY.
CAUTION: possible instrument damage or malfunction.

NOTE: important operating information

SERVICE AND REPAIR INFORMATION

This manual provides instruction to properly setup and operate the 550 model TOC
Analyzers. Tampering with, modifying, or dis-assembly of any internal components of
this analyzer beyond that, which is explicitly spelled out in this manual, is prohibited and
will render the manufacturers warranty null and void.

TABLE OF CONTENTS

CHAPTER 1: GETTING STARTED................................................................................ 5

INTRODUCTION........................................................................................................5

PRINCIPLE OF OPERATION ....................................................................................6

CHAPTER 2: INSTALLATION / SET-UP........................................................................ 8

LOCATION.................................................................................................................8

ELECTRICAL CONNECTIONS..................................................................................8

SAMPLE TUBING CONNECTIONS...........................................................................8

ANALOG OUTPUT.....................................................................................................9

ALARMS.....................................................................................................................9

USER INTERFACE/PRINTER ...................................................................................9

START-UP ...............................................................................................................10

CHAPTER 3: CONFIGURATION.................................................................................. 12

USER SETUP AND CONFIGURATION MENUS.....................................................13

CALENDAR..............................................................................................................14

SYSTEM NAME.......................................................................................................15

OUTPUT SETUP......................................................................................................15

ALARM SETUP, CODES, and SETPOINTS............................................................15

ALARM-X(1 OR 2) MODE CONFIGURATION.........................................................16

PRINT SET-UP ........................................................................................................16

ANALOG (4-20 mA) OUTPUT..................................................................................17

AUTO START...........................................................................................................17

MEASUREMENT DISPLAY .....................................................................................18

AUTOMATIC ZERO CALIBRATION CONTROL......................................................18

PRINTOUT OF CONFIGURATION DATABASE......................................................19

CHAPTER 4: DEMONSTRATION MODE..................................................................... 20

CHAPTER 5: OPERATION........................................................................................... 21

POWER ON .............................................................................................................21

BEFORE MEASURING............................................................................................21

MEASURING............................................................................................................21

TREND DATA CLEAR .............................................................................................22

PRINT TREND DATA...............................................................................................22

ALARM SETPOINT SCREEN..................................................................................23

ALARM INDICATION ...............................................................................................23

ERROR CODES.......................................................................................................24

END MEASUREMENT.............................................................................................25

CHAPTER 6: MAINTENANCE......................................................................................26

LAMP REPLACEMENT............................................................................................26

CHAPTER 7: CALIBRATION ....................................................................................... 28

ANALOG OUTPUT CALIBRATION..........................................................................28

AUTO ZERO CALIBRATION ...................................................................................29

BOARD CALIBRATION............................................................................................29

MEASUREMENT VERIFICATION/CALIBRATION ..................................................33

CHAPTER 8: ADVANCED CONFIGURATION............................................................. 35

ADVANCED START UP METHODS........................................................................35

VIEWING SENSORS...............................................................................................37

TOC CURVE............................................................................................................38

APPENDIX A................................................................................................................ 40

KEY/DISPLAY FUNCTIONS....................................................................................40

SYSTEM CHECK SEQUENCE................................................................................41

550 OPERATION CHART - Measurement Mode.....................................................42

550 OPERATION CHART - Setup Mode .................................................................43

550 OPERATION CHART - Setup Mode (Maintenance menus)..............................44

550 OPERATION CHART - Maintenance Mode (Other Setup menus)....................45

OPTIONAL PRINTER DIP SWITCH SETTINGS..................................................... 46

SPECIFICATIONS........................................................................................................ 47

ACCESSORIES AND REPLACEMENT PARTS .......................................................... 48

CE DECLARATION OF CONFORMITY ....................................................................... 49

DECLARATION OF CSA COMPLIANCE.....................................................................50

APPLICABLE REQUIREMENTS..............................................................................50

WARRANTY.................................................................................................................. 51

CHAPTER 1: GETTING STARTED

INTRODUCTION

Total Organic Carbon measurement is recognized in many industries as an important,
and some cases, required measurement parameter for process certification and
performance verification. It is evident that a fast response, easy to operate and
maintain, device has recognizable benefits for the user.

The Thornton 550 Total Organic Carbon Analyzer provides a faster and easier method
of on line measurement. As its predecessor, the 502P, the 550 TOC analyzer units
offers the widest dynamic water quality range that can be measured without
cumbersome reagents or accessories. And it is the only known TOC Analyzer to
measure on-line continuously.

The 550 TOC Analyzer is an online device that can be used in a permanent installation
and also as a portable device. TOC measurement is capable throughout a range of 0.1
to 1000 ppb for the standard and high temperature models, 0.05 to 30 ppb for the SX
model.

The Mettler-Toledo Thornton, Inc. factory provides in-house calibrations and testing
services and also offers Field Service support (consult local factory sales
representatives for details).

The Specifications, Principal of Operation, Installation, Configuration, Operation,
Maintenance, and Calibration of this unique, high-quality analyzer follow. If you have
any questions or comments about this manual, or the analyzer itself, please do not
hesitate to contact us.

United States Patent (No. 5,518,608) issued.

GETTING STARTED 5

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PRINCIPLE OF OPERATION

The Thornton 550 TOC Analyzer measures Total Organic Carbon in pure and ultrapure
water based on differential conductivity. This difference in conductivity is used to
determine the amount of organic carbon present.

Sample

Sample

Inle

Inle

Pressure

Control Valve

Conductivit

Sensor (1)

UV Oxidation

Conductivit

Sensor (2)

Flow

Meter

Flow

Control Valve

Oxidized

Sample

Outle

Resistivit

Sensor (3)

Flow Orifice

By-pass

Sample Outle

CPU

Printer

(Optional)

LCD

Displa

4-20 mA

nalo

Outpu

Terminal

TOC
Temperature
Resistivit

The sample water enters the analyzer and passes through a pressure regulator, which
controls sample pressure to downstream components. Here the sample splits into two
flow paths, where a portion of the flow is directed to the by-pass streamline, where
resistivity/conductivity and temperature are measured via Sensor (3). These values are
represented on the LCD display.

The other portion of the sample is directed through a second conductivity sensor, (1),
measuring the sample conductivity prior to oxidation. Next, the sample enters the
oxidation chamber. As the sample moves through the oxidation chamber, it is
subjected to high intensity ultraviolet radiation at 185 nm, effectively oxidizing the
sample to CO

.

2

After oxidation, the sample passes through a third conductivity sensor, (2), where the
conductivity and temperature are measured again to determine the level of Total
Organic Carbon (TOC).

The microprocessor of the Thornton 550 TOC Analyzer uses the measured values of
initial (1) and final (2) conductivity and temperature to determine the change in
compensated conductivity, which is related to the concentration of organic impurity in
the incoming water stream.

The measurement and sample flow are continuous; therefore, measurement update
time is minimized, providing rapid response to any system disturbances.

The oxidized sample stream passes through a flow meter, which has a fine flow-control
adjustment, and then through the OXIDIZED SAMPLE OUTLET port. This effluent may
be sent to waste or recycled. The operating flow rate is typically 20 ml/min, resulting in

6 GETTING STARTED

residence time in the oxidation chamber of less then one minute. The conductivity
measurements are continuous; therefore, response time is directly related to the
residence time of the sample in the oxidation chamber.

Values of TOC, resistivity (or alternatively conductivity or uncompensated conductivity),
and temperature are displayed on the LCD screen of the instrument. These values can
also be printed or sent to a computer through RS-232 serial interface ports on the back
panel of the instrument at a user-selectable time interval. The last 255 sets of values
are stored in memory at the same time interval for viewing on the screen, or a
designated number of these data lines can be printed on a demand basis. Other
outputs include a continuous 4-20mA self-powered analog output signal and two
configurable potential-free alarm contacts. Refer to the specifications in the back of this
manual for details regarding these outputs

GETTING STARTED 7

CHAPTER 2: INSTALLATION / SET-UP

LOCATION

The Thornton 550 TOC Analyzer is to be installed in a dry environment with a relative
humidity <80% (non-condensing) and with ambient temperature between 5 and 40°C
(41 to 104°F), on a flat, horizontal surface. The sample inlet line should be fitted with
an isolation valve. The OXIDIZED SAMPLE OUTLET and BYPASS SAMPLE OUTLET
tubes are led to waste (or a water reclaim system) at atmospheric pressure without any
obstructions in the tubing.

ELECTRICAL CONNECTIONS

A power outlet must be available within 3 ft. (1 m) when using the 3-pronged power
cord supplied with the analyzer. An adapter for the power cord may be necessary for
outlets of different configurations, depending on the country in which the unit is
installed. The unit requires a power source between 100 and 240 VAC at either 50 or
60 Hz. Maximum power consumption is 50 W (with optional printer installed).

SAMPLE TUBING CONNECTIONS

Three pieces of 2.5 m (8 ft) tubing are supplied with the unit. Two pieces are relatively
clear and the third (PFA or similar Teflon material) is opaque. The Teflon tubing is

used for connection from the sample water line to the SAMPLE INLET port on the back
panel of the Analyzer. Hardware is to be assembled on the tubing as shown below for
connection of the tubing to its port.

8 INSTALLATION / SET-UP

The tubing can be shortened to your application. Shorter tubing provides faster
response time. Sample water pressure must be a least 0,5 bar (7.0 psi) but not greater
than 7 bar (100 psi). A pressure regulator, located inside the Analyzer, protects the
spiral quartz tube from damage by excessive inlet pressure.

The pieces of clear tubing are to be connected from the BYPASS OUT and from the
OXIDIZED OUT ports to the user’s drain at atmospheric pressure, without bends or
kinks in the lines. Likewise, these two pieces of tubing can be shortened, although this
will have no effect on performance.

ANALOG OUTPUT

The two terminal connections on the left-hand side of the terminal strip on the back
panel can be used for a self-powered 4-20 mA output. This ouput can be configured for
remote use of TOC (most common), resistivity, or temperature signal. The maximum
load resistance is 500 ohm.

ALARMS

Two sets of alarm connections, Normally Open, Normally Closed and common, are
provided on the same terminal strip. Each alarm can be independently configured as
either NO (Normally Open) or NC (Normally Closed).

ALARM 1 ALARM 2

NO1 COM1 NC1 NO2 COM2 NC2

Each alarm output is driven by a SPDT relay rated at 0.4A @ 120 VAC or 2.0A @
30 VDC. See CHAPTER 3: CONFIGURATION for more information.

USER INTERFACE/PRINTER

Two RS232 connections are available and located on the rear-panel of the analyzer.
PRINTER

The connection labeled ‘PRINTER’ is a 9-pin, male or female, sub-D connection for
connecting an optional printer, with serial interface. The printer port can also be
connected to a computer having a serial interface.

Communication specifications for this port: 9600 baud; 1 stop bit; no parity; 8-bit data.
Mettler-Toledo Thornton, Inc. supplies a small format thermal printer as an optional

accessory. A straight-through 9 pin, male or female, sub-D cable is provided with this
printer. Configuration (Dip switch settings) for this optional printer can be found in the
APPENDIX. An operation manual is also included with the printer. Power for this
printer is supplied by the 550 TOC ANALYZER (6 VDC). The power connection is
made at the rear of the analyzer.

RS232C
The connection labeled “RS232C’ is also a 9-pin sub-D connection for connecting a
computer using a serial interface. This port, used in conjunction with a computer having
serial interface capability, can be used as an alternate means to collect the operating

INSTALLATION / SET-UP 9

data from the analyzer. The Computer must have the means to collect this serial data,
which will be transmitted in the same format as it is transmitted to the optional printer.
The following communication specifications apply.

Communication specifications for this port: 2400 baud; 1 stop bit; no parity; 8-bit data.
Software such as HyperTerminal, a standard Windows® based software, may be
utilized to collect data with a PC.

START-UP

After all the tubing has been connected, sample water can flow through the unit. Open
the user-furnished sample isolation valve. Observe the flow rate from the flow meter on
the front panel of the Thornton 550 TOC Analyzer. Adjust the flow rate to the maximum
setting by means of the flow adjustment knob, located at the top of the flow meter. If not
already installed, connect the power cord to the socket located at the rear of the
Thornton 550 TOC analyzer and insure the other end is connected to a suitable power
source. Press the power button located at the rear of the analyzer to ON. This will
enable the front display screen showing the Thornton name, model # and software
version of the analyzer.

At this time, the analyzer should be rinsing with sample water to remove any impurity
present on the sensors or in the system tubing and components. This will also help
remove air bubbles, as any entrained air can cause errors in readings. Upon initial
installation and start-up, it is recommended that the analyzer be rinsed for a minimum
of 4 hours to 12 hours. The analyzer can be used immediately, but depending on water
quality, time may be needed for readings to stabilize.

If the desired flow rate is not achievable, the internal pressure regulator may have to be
adjusted. With the power to the Analyzer turned off and the power cord disconnected
from the power source, remove the top cover. Depress each of the four buttons on
opposite sides, just under the lip of the top cover, so that each of the 4 strips on top lifts

open. The exposed, large Phillips-head screws can now be loosened so that the top
cover can be removed.

Note: There is a proper front and back to the cover. The bottom sides of the cover
have male and female grooves, respectively. When replacing the cover, make sure the
female groove on the cover lines up with the male mating surface on the housing on
one side; the genders will be reversed on the other side.

The pressure regulator can be seen toward the back left of the analyzer, near the
sample inlet and outlet connections. First, rotate the flow adjustment knob on the front
of the analyzer counterclockwise, to the full open position. Then, on the internal
pressure regulator, rotate the knob on the top of the regulator to adjust the pressure
until the flow reads 100 ml/min.

10 INSTALLATION / SET-UP

After rinsing, use the flow adjustment knob to set the flow to 20 ml/min.
CAUTION: Even if no pressure adjustment is required (which is the usual case); the

cover should be removed so that the analyzer can be checked for water leaks, as any
leak could be a source of error in the readings and also could lead to damage or failure
of the unit.

When all of these installation steps have been completed, replace the top cover, plug in
the power cord, and press the power button, at the rear of the analyzer, to ON.

INSTALLATION / SET-UP 11

p

CHAPTER 3: CONFIGURATION

The unit can be configured before or after installation as described in Chapter 2. When
the unit is first powered, the following “TITLE” display will be seen.

Symbol Name Major function

THORNTON
550 TOC Analyzer
Ver 1. XX

Esc

Next

Up

Down

Menus

Enter

Save

Save/

Sto

Menus Menu key Enter menu display
Save Save key Save changes
Start/ Stop Start measurement

Stop measurement
Up key Increase number / move the cursor or

Up

Down key Decrease number / move the cursor or

Down

Start measuring TOC
Stop measuring TOC

check mark (＊)

check mark (＊)

Enter Enter key Enter or exit from a menu line
Esc Escape key Escape from the current menu level to the

previous menu level

Next Next key Scroll the menu displays / move cursor

12 CONFIGURATION

The 550 is available in three different models, the standard unit, known simply as the
550 will display the title as shown above. The High Temperature version will show the
model number 550-HT and the enhanced resolution version will display the model
number 550-SX. The current software version installed is also displayed below the
model number.

This title screen will also display two other status indicators, when programmed to do
so. In the bottom right-hand corner the word “Demo” will flash, indicating that the
analyzer has been placed into demonstration mode. Also, it may flash “Auto Start ON,”
when the analyzer has been programmed to do so.

As shown above the front panel of the 550 provides (8) eight keys for manipulation of
the unit’s set-up, configuration, and maintenance menus. See KEYPAD/DISPLAY
FUNCTIONS Table in the APPENDIX for a detailed description of the function of each
key.

USER SETUP AND CONFIGURATION MENUS

When the unit is in Standby mode, the first level of menu displays can be accessed by
pushing the MENUS key. This array of menus will be used to setup or change the
configuration of the 550 TOC Analyzer for normal operation. The 550 software contains
a lockout function that when enabled allows configuration changes only if a password is
entered. The screens should appear as follows:

NOTE: If lockout is enabled (‘Lockout ON’), when pushing the MENUS key from the
Title Screen, the next screen will ask for Password Input. The factory default for this
password is ‘0000’, (all zeros). The password can be configured for a personalized
four-digit password from the Maintenance Menus. Otherwise pushing the Menus key
from the Title screen will display the main menus.

Push MENUS key to enter the password screen as shown below:

Push ENTER Key to view the 1st page of the main menus as shown here:

THORNTON
550 TOC ANALYZER
Ver 1.XX

PASS WORD INPUT
PASS WORD 0000

(Lock Out ON)

1.*ALARM – 1 MODE

2. ALARM – 2 MODE

3. ALARM VALUE

4. ALARM DELAY

CONFIGURATION 13

Push the NEXT key to view the 2nd page of the main menus as shown here:

5. *PRINT SETUP

6. ANALOG SETUP

7. ANALOG CALIB

8. UV TIME

Push the NEXT key again to see the 3rd main menus as shown here:

9. *CALENDAR SETUP

10. SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. MAINTENANCE

The above menus are the (12) twelve main menus used for set-up, configuration and
maintenance of the 550 TOC Analyzer

CALENDAR

First, set the Calendar by pushing the MENUS key. Once at the 1st menu screen, push
the NEXT key until you reach the 3rd menus screen shown below:

9. *CALENDAR SETUP

10. SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. MAINTENANCE

If necessary move the * to 9. CALENDAR SETUP using the DOWN key.
Press ENTER.

Calendar Setup
yy/mm/dd *2003/07/20
hh/mm/ss 11:20:35

This is a 24-hour clock. Press ENTER to access the yy/mm/dd fields. Use the NEXT
key to move the cursor to the number to be changed. Use the UP/DOWN keys to
change the number. After adjusting the date, press ENTER and move the * with the
DOWN key to the time. Adjust in the same manner. “SET OK” will flash. Press ESC to
return to the previous menu screen.

Note: The calendar is backed up by a battery on the printed circuit board.

Confirm the time if the unit has not been powered for several weeks.

14 CONFIGURATION

Now that the general method of key/display is known, the remaining functions can be
easily performed. Refer to the Appendix for a table of KEY/DISPLAY FUNCTIONS and
the Operation Flow Charts.

SYSTEM NAME

Go to “10. System Config 1” (on 3rd page of main menus) by moving the asterisk with
the up/ and down keys, until it is on line 10.

Press ENTER.

Press ENTER to highlight the first digit and using the UP, DOWN and NEXT keys, the
Sys Name may be set at 0000 or it may be an abbreviated form of the serial number.
For example, for S/N 960012, the Sys Name would be 9612. This is arbitrary, and it
can be changed by the user.

9. CALENDAR SETUP

10. *SYSTEM CONFIG1

11. SYSTEM CONFIG 2

12. MAINTENANCE

SYSTEM CONFIG 1
Sys Name *0000
Print-T unit min.
Program Ver x.xx

OUTPUT SETUP

This section provides instruction for setup of the 550 outputs. If you are using this
Analyzer for measurement only, you may proceed to the Auto Start section of
configuration. Otherwise, configure outputs as described in the sections below.

ALARM SETUP, CODES, and SETPOINTS

The Thornton 550 has two independent relay alarms. Each can be configured for one
of the three measurement parameters on the display. Choose the parameter and set
point. The condition (NO or NC) for each relay is determined by the wiring terminals
selected (see INSTALLATION). Configuring the alarms requires the following
procedure. There is also a menu tree in Appendix B:

From the title screen press MENUS.
Move to 1. ALARM MODE-1 or 2. ALARM MODE-2.
Press ENTER to reach the following screen display for either alarm:

.

ALARM-1 MODE
ITEM = *ppb
RELAY = High On
HIST. = 00

CONFIGURATION 15

ALARM-X (1 OR 2) MODE CONFIGURATION

ITEM
Select output parameter ppb = TOC
Mohm = Resistivity

°C = Temperature of sample water
ERset = Error
None = no output
RELAY
Definition of relay activation
Low Off = Relay off at lower than set point
Low On = Relay on at lower than set point
High Off = Relay off at higher than set point

High On = Relay on at higher than set point
If Erset is selected in parameter, relay activation is automatically set to ON
HIST.

This sets the Hysteresis associated with the alarm set point. A value from 0 to
99 can be entered.
HIST. = XX (0 to 99)

PRINT SET-UP

If an optional printer is used, set up the printing of measurement data as follows:
In the MAIN Menus, 2nd screen Select: 5. Print Setup

Print Setup
Print Time = 0
History Wrt = OFF
Nr. Of Data = 0000

1 Sec

Print time is the interval between printing, in seconds, minutes or hours. This display
shows an interval of 1. To change this value, move the cursor to the appropriate digit
with the NEXT key; then UP or DOW N to change the value.

Ranges for print intervals are: 1-99 seconds, 1 - 99 minutes and 1-99 hours, all in
increments of 1 (sec., min or hr.). This same time also determines Trend Data display
(see OPERATION). To program the units of the Print Time and Trend Data, go to

10.System Configuration 1. Press Enter.

SYSTEM CONFIG 1
Sys Name 0000
Print-T unit *sec
Program Ver x.xx

Using the down key move the cursor to Print-T unit. Press enter. Using the up key
change the unit to sec, min, or hour. Press enter. Press save. Select yes by using the

Use of History Wrt and Nr. Of Data are
explained in OPERATION.

16 CONFIGURATION

up key. Press enter. Note: Changing Print-T unit will reset the print time to 01. Press
the esc key twice to return to the title screen.

ANALOG (4-20 mA) OUTPUT

In the MAIN menus, 2nd screen, Select: 6. 4-20 mA SETUP

The Output options are as follow:

In the above display, the 4-20 mA output is configured for TOC. The 4mA output
represents 0.0 ppb TOC, and 20 mA represents 100.0 ppb TOC. These limit values are
user selectable with values of 000.0 to 999.9.

ANALOG SETUP
Output = *ppb
4mA Lmt = 000.0
20mA Lmt = 100.0

ppb TOC (ppb)
Mohm Resistivity (Mohm-cm)

°C Temperature (°C)
Hold Holds current value (Used for 4-20 mA calibration)
Not Select Analog signal configured, output not used
None No configuration, output not used

AUTO START

In the MAIN Menus, Refer to 11. SYSTEM CONFIG 2:

Press ENTER.

When AUTO START is set to OFF, the operator must push START to initiate the
measuring process. When it is set to ON, the measurement process begins any time
the unit goes from the unpowered to the powered state. (This could be the result of the
operator switching the power ON, or from restoration of power after an outage.) It is
recommended that this be left OFF for initial operation in a particular application. To
change the status insure the asterisk is in front of the OFF on the AUTO START line,
press the ENTER key, and use UP/DOWN keys to toggle OFF/ON. Press SAVE to
write to memory.

9. CALENDAR SETUP

10. SYSTEM CONFIG1

11. *SYSTEM CONFIG2

12. MAINTENANCE

SYSTEM CONFIG 2
Auto Start *OFF
Print SYS Config OFF
History Clear OFF

CONFIGURATION 17

MEASUREMENT DISPLAY

The user has the option of displaying the measurement value of the incoming water
sample as resistivity, conductivity, or (temperature) uncompensated conductivity. To
change from the default value of resistivity:

Go to MEASURE PARA 2, choose 12: MAINTENANCE, Then move the asterisk to 11.
Other Setup. After entering Other Setup, set Write to ON to edit Other Setup
parameters.

Press Enter.

Press Enter.
Press Next 3 times to go to 4. MEASURE PARA 2 screen.

In the RESERVE2 line, the codes for measurement display are set by the fourth digit as
follows:

The display will indicate MΩ-cm o r µS/cm according to the code selected.

MAINTENANCE 4/4

10. A/D View
*11. Other Setup

Other Setup
Write ON

4. MEASURE PARA 2
RESERVE2 0000
RESERVE3 1000
Sensor Status 0000

XXX0

Resistivity (MΩ-cm)
XXX1 Conductivity (µS/cm)
XXX2 Uncompensated Conductivity (µS/cm)

AUTOMATIC ZERO CALIBRATION CONTROL

Zero calibration is to account for the small differences in measurement between
Sensor-1 (S1) and Sensor-2 (S2). A zero calibration is performed by the “System
Check” routine each time the START button is pushed to start measuring. This is
explained in ADVANCED CONFIGURATION. However, the system can be configured
to automatically zero-calibrate at set time intervals by use of the first digit from the left in
RESERVE2 of MEASURE PARA2, shown above.

18 CONFIGURATION

Reserve2 Period of Auto Zero

0XXX No Aut o Zero
1XXX 20 hours
2XXX 40 hours

XXX 60 hours

3
4

XXX 80 hours
5XXX 100 hours
6XXX 200 hours
7XXX 1000 hours

After changing this parameter, press Save to write it to memory; then switch the power
OFF, then ON. Note the following:

1. The second digit of RESERVE2 is used to configure the communication port.
The third digit is used for special functions only, and is normally zero. Its
function is explained in ADVANCED CONFIGURATION.

2. RESERVE3 is not used and is normally set to 1000.

3. Sensor Status is normally 0000. It is changed only in certain operating
situations, as explained in ADVANCED CONFIGURATION.

For any application outside the normal operating parameters, please consult
Mettler- Toledo Thornton, Inc. technical support department.

PRINTOUT OF CONFIGURATION DATABASE

A printer attached to the printer port can be used to print out the configuration
database. This is advisable for documentation and helpful for troubleshooting. To print
out the configuration database:

1. STOP measuring by pressing the START/STOP button.

2. Push Menus and page down to 11. SYSTEM CONFIG 2 using the NEXT and
DOWN keys.

3. Press ENTER key

4. Select Print SYS Conf. using the DOWN key and pressing ENTER. Toggle ON,
using UP/DOWN keys and press ENTER.

All configuration parameters in the database will now be printed through the printer port.

9. CALENDAR SETUP

10. SYSTEM CONFIG 1

11. *SYSTEM CONFIG 2

12. MAINTENANCE

SYSTEM CONFIG 2
Auto Start OFF
Print SYS Conf. *OFF
History Clear OFF

CONFIGURATION 19

CHAPTER 4: DEMONSTRATION MODE

The Thornton 550 can be run in the Dem onstration Mode to illustrate and allow practice
in changing some of the parameters prior to actual use of the instrument. While the
measurement value cannot be changed, other parameters, such as alarm set points,
can be altered.

To access the Demo Mode, go to 12. Maintenance, using the Menus, NEXT and
DOWN keys.

After entering the Password (FACTORY default is “0000’) using the UP and ENTER
keys, the first screen, maintenance 1/4 will display.

The default selection is *1. Demo Mode On/Off. ENTER will display the Demo
ON/OFF screen as follows:

Use UP to toggle to ON. Go back to the title screen by pressing the ESC key 3 times.
In the lower right corner of the display “DEMO” will appear. If it does not the unit is not
in demonstration mode. Push the START key, and the System Check cycle will
commence. After about 3 min, the display will indicate SYSTEM CHECK PASSED and
that the UV is ON. This is for simulation only: the lamp is not actually powered.
Then, after about 2 min, the measurement screen appears.

Pushing the START/STOP key again returns the display to the TITLE screen.
Other functions can be examined and values, such as alarm set points, can be changed

for purposes of demonstration. Refer to CONFIGURATION and also the Operation
Flow Chart in the APPENDIX.

When finished, return to the Playing Demo screen to turn Demo OFF.

9. CALENDAR SETUP

10. SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. *MAINTENANCE

MAINTENANCE 1/4

*1. Demo Mode On/Off

2. Sensor View

3. EEPROM Setup

Playing Demo
Demo Mark Off

20 DEMONSTRATION MODE

CHAPTER 5: OPERATION

POWER ON

Turn on the power at the switch on the rear panel of the Analyzer.

BEFORE MEASURING

Before starting to measure, be sure the flow rate is adjusted to 20 ml/min (unless
otherwise specified for your application.)

MEASURING

THORNTON
550 TOC Analyzer
Ver x.xx

TITLE Screen will appear as shown. High
temperature units display 550-HT and SX units
display 550-SX.

Push START to initiate the System Check and Measure process.

SYSTEM CHECK
Please Wait

RESIST = 18.20 MΩ-cm

SYSTEM CHECK is blinking. The analyzer
does an automatic zeroing to correct for any
drift.

↓↓↓↓

SYSTEMCHECK PASSED
UV WARMING UP
Please Wait

RESIST = 18.20 MΩ-cm

SYSTEM CHECK PASSED now solid.
UV Warming Up is blinking.
UV Lamp is stabilizing during this period.

↓↓↓↓

TOC = 200.32 ppb
RES = 18.21 MΩ.cm
TMP = 25.6 °C

Primary Measurement Display.
Measurement is updated every 2 seconds.

Trend data can be viewed by pushing NEXT. ESC returns to the Measurement
Display.

TIME TOC RES TP
10:30 75.2 18.2 25
11:00 100.2 17.6 25
11:30 200.6 17.2 25

Time interval is determined by Print Setup.
See PRINT SETUP.

OPERATION 21

From the above screen, the Measurement Trend Check Mode can be accessed with
ENTER. The past record of measurement values can be accessed with UP/DOWN.
Pressing ENTER again will show the three most current readings on the display.

TIME TOC RES TP
10:30* 75.2 18.2 25
11:00* 100.2 17.6 25
11:30* 200.6 17.2 25

255 Lines of data are stored. The values are
the instantaneous measurement at the time
shown, not an average value.

ESC will return the display to the regular Measurement screen.

TREND DATA CLEAR

If the unit has been moved and a new sample is being introduced, or it is otherwise
desirable, the trend data can be erased. First, stop measurement with the
START/STOP button. Press Menus key and then access TREND CLEAR in 11.
System Config2 using the NEXT and DOWN keys.

Press ENTER key.

Select History Clear using the DOWN key and press ENTER. Toggle to ON using
UP/DOWN keys, and press ENTER. The trend data will be cleared.

9. CALENDAR SETUP

10. SYSTEM CONFIG 1

11. *SYSTEM CONFIG 2

12. MAINTENANCE

SYSTEM CONFIG 2
Auto Start OFF
Print SYS Conf. OFF
History Clear *OFF

PRINT TREND DATA

If a printer is connected to the printer port, the measurement trend data can be printed.
Push Menus and move the asterisk to item 5. PRINT SETUP. Press ENTER to enter
this menu.

Press Enter.

22 OPERATION

5. *PRINT SETUP

6. ANALOG SETUP

7. ANALOG CALIB

8. UV TIME

Print Setup
Print Time = 10 sec
History Wrt = OFF
Nr. of Data = *0010

A

Select Nr. Of Data using the DOWN key and press ENTER. Move the cursor using the
NEXT key and change to the desired number of most recent data lines you wish to print
with the UP/DOWN keys. Press ENTER. Next, select History Write using the UP key,
press ENTER and toggle ON using the UP/DOWN keys. Press ENTER. The number
of data lines you selected will print out.

Push ESC twice to return to the Measurement Display.

ALARM SETPOINT SCREEN

From the Measurement Screen, the Alarm Set point Screen can be accessed pressing
NEXT twice (see APPENDIX).

This display shows the set point values for

ALM1 = 450.5 ppb
ALM2 = 10.3 Mohm
T.F = 1.234 R.F = 0.987
UV TIME = 200 Hours

NEXT returns the display to the measurement screen.

Alarms 1 & 2. These are read-only and cannot
be changed from this screen. TF and RF are

values from 6. TOC Calib in MAINTENANCE
2/4. UV TIME is the total number of hours the

present lamp has been used.

ALARM INDICATION

If an alarm condition is present, or occurs during measurement, an alarm message will
appear in the measurement display. For example:

TOC = 200.32 ppb
RES = 18.21 MΩ
TMP = 25.6°C

L1 H UV

ERROR 16
TMP1 OVER

This indicates that Alarm 1, a high alarm, has
been activated. “UV” indicates that the
recommended lamp life of 4,000 hours has
been exceeded.

If a malfunction or abnormality occurs, an error
screen will appear, and will alternate with the
measurement screen.

According to the Error Code Table (see below),
this indicates the temperature at Sensor-3
(Incoming Sample) is too high.

OPERATION 23

ERROR CODES

Message Fault Cause

SYSTEM CHECK
FAILED

Unable to measure TOC Differential between sensors

before UV oxidation is too great

ERROR 02 Unable to measure TOC Conductivity of sample water is

greater than 20 µS/cm

ERROR 03 Sensor 1 error Sensor 1 cable not connected,

or sensor fault

ERROR 08 Sensor 2 error Sensor 2 cable not connected,

or sensor fault

ERROR 13 Sensor 3 error Sensor 3 cable not connected,

or sensor fault
ERROR 18 UV lamp life finished Replace UV lamp
ERROR 06
ERROR 11

Sensor 1 temperature error
Sensor 2 temperature error

Temperature Sensor error, or

temperature above allowable

limit
ERROR 16

ERROR 07
ERROR 12

Sensor 3 temperature error
Sensor 1 temperature error
Sensor 2 temperature error

Temperature Sensor error, or

temperature below allowable

limit
ERROR 17

Sensor 3 temperature error

Error 02, which prevents measurement, can be overridden using the “Sensor Status”
function in MEASURE PARA 2. SEE CHAPTER 8 “ADVANCED CONFIGURATION”.

Press SETUP and select item 12. MAINTENANCE by pressing the NEXT and DOWN
keys.

9. CALENDER SETUP

10. SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. *MAINTENANCE

Press ENTER, enter the Password, (Factory default is 0000), using the UP and ENTER
keys, the first screen, MAINTENANCE 1/4, will display. Using the DOWN/UP keys,
select Item 11.Other Setup.

MAINTENANCE 4/4

10. A/D View
*11. Other Setup

Press ENTER. Use UP/DOWN to toggle to ON. Press ENTER.

24 OPERATION

Using the NEXT key, select MEASURE PARA 2 screen (fourth screen in ‘Other Setup’
menu) and select Sensor Status using the DOWN key.

4. MEASURE PARA2
RESERVE 0000
RESERVE 0000
Sensor Status *0000

Change Sensor Status from 0XXX to 1XXX
by pressing ENTER and UP keys.
Refer to ADVANCED CONFIGURATION for
more information.

END MEASUREMENT

To terminate measurement at any time, press START/STOP, and the display will return
to the TITLE screen.

OPERATION 25

CHAPTER 6: MAINTENANCE

LAMP REPLACEMENT

The only maintenance that is required on a regular basis is replacement of the UV
lamp. W hen the lamp usage time has reached 4,000 hours, a UV lamp alarm appears
on the display. At some point after 4,000 hours, the UV radiation will gradually degrade
and eventually will affect the validity of the measurement.

WARNING: Do not remove back cover with unit ON or Power to the

unit ON. UV light is harmful to the eyes.

1. Stop measuring by pushing the START/STOP key.

2. Switch power OFF.

3. Disconnect the power cord.

4. Allow unit to cool 10 minutes before changing the lamp.

5. Remove the round plate on the back panel of the analyzer.

6. Unplug the UV lamp lead.

7. Pull the lamp straight back, loosening it from its socket, and removing it from the
unit.

8. The reverse procedure is used to install the new lamp. Grasp the new lamp at
its outboard end, being careful not to touch the glass, and insert the lamp in
the socket. If the glass portion of the lamp has been exposed to fingerprints or
contaminants, clean the lamp with a high purity grade of methanol and a
scratch-free cloth or towel.

9. Replace the round plate.

10. Connect the power cord.

11. Turn power ON.

The UV time must now be cleared in the software, so that the timer will start with 0
hours for the new lamp. The UV TIME CLR is accessed as follows:

• Press MENUS.

• Scroll to 12. MAINTENANCE using the down key.

• Press Enter and change Password (Factory Default is 0000) using the UP key.

• Select MAINTE NA NCE 4/4 using UP/DOWN key.

• Scroll to 11. Other Setup using the DOWN key.

• Press ENTER and Toggle ON using UP/DOWN key. Press ENTER

• Press NEXT to access 5. UV TIME:

• Select UV TIME CLR using the DOWN key.

5.UV TIME
UV ON TIME = *0020
UV CHG TIME = 4000
UV TIME CLR = OFF

26 MAINTENANCE

UV TIME
UV ON TIME = 0020
UV CHG TIME = 4000
UV TIME CLR = *OFF

• Press ENTER and toggle UV TIME CLR to ON using the UP/DOWN key and
press ENTER. UV ON TIME will reset to 0000.

• UV TIME CLEAR will automatically return to OFF after clearing.

• Press ESC three times to return to TITLE screen.

• Press START to resume measurement.

MAINTENANCE 27

CHAPTER 7: CALIBRATION

Four aspects of Calibration are covered in this section.

• Analog Output Calibration. This procedure is used to calibrate the analog output
loop.

• Auto Zero Calibration. This is a procedure, performed by the monitor itself, to
obtain zero readings of the two TOC sensors and correct for any zero drift.

• Measurement Verification/Calibration. These are methods for verifying that the
current calibration is valid, or to adjust factors for re-calibration.

• Sensor Board Calibration. This procedure calibrates the main PC board with a
set of resistors, and it ensures that the electronics measure resistivity accurately.

ANALOG OUTPUT CALIBRATION

The analog output loop can be calibrated as follows. From the title screen press the
Menus key. Go to 6.ANALOG SETUP. Press Enter.

Press ENTER and set the output to hold by using the UP key. Press ENTER
It is not necessary to push SAVE, as this is a temporary condition only and should not

be written on the EEPROM.
Press ESC to exit back to the menu options and, with Down, select 7. ANALOG CALIB

Press ENTER

Since this is a digital device, only 2 points are necessary to calibrate the 4-20 mA
output. At HOLD = 00, adjust the 4 mA LOW (otherwise meaningless) number until the
output, as measured with a current meter reads 4 mA.

At HOLD = 100, do likewise for the 20 mA output value.
For calibrating a 4-20 mA analog receiver loop, such as one with a pen recorder, the

additional intermediate HOLD values of 25 (8 mA), 50 (12 mA), and 75 (16 mA) can be
employed. Adjust the receiver instrument indication to conform to these output values.
After completion of the loop calibration, Press ESC and go to 6. ANALOG SETUP and
change the Output code from hold.

ANALOG SETUP
Output = *hold
4mA Lmt = 000.0
20mA Lmt = 500.0

ANALOG CALIB.
4 mA LOW = *1000
20mA HI = 1000
HOLD = 00

28 CALIBRATION

AUTO ZERO CALIBRATION

TOC measurement depends upon the difference in conductivity readings between
Sensor 1 and Sensor 2. As with any electronic measurement device, the zero may drift
slightly over a period of time. In order to maintain a high accuracy measurement, these
two sensors should be auto-balanced.

This routine is actually initiated every time the START/STOP key is pressed to start the
measurement. This is indicated on the display screen as “System Check.” Also, the
instrument can be configured to initiate this routine at specified time intervals. This is
achieved by setting the first digit from the left in RESERVE2 of MEASURE PARA2.
See APPENDIX A for location of MEASURE PARA2 and AUTOMATIC ZERO
CALIBRATION CONTROL for a table of Period of Auto Zero.

This Auto Zero Calibration is important for measurement in high-purity water. However,
if the resistivity of the water is 10 MΩ-cm or lower, Auto Zero Calibration is not

necessary, and the first digit of RESERVE2 should be left at 0.
If Auto Start has been set to ON, the Auto Zero Calibration (“System Check”) will

commence anytime the unit is switched ON or returns to a powered condition after a
power outage. Auto Start is found in SYSTEM CONFIG2. See APPENDIX and

CONFIGURATION. For a further explanation of the Auto Zero Routine, refer to
ADVANCED CONFIGURATION.

BOARD CALIBRATION

This section describes a procedure to verify the functionality and accuracy of the
electronics within the instrument. The Thornton 550 TOC Analyzer has two sensors for
TOC measurement and one sensor for measurement of the incoming water sample.
These sensors are connected to the motherboard of the 550.

Periodically, the motherboard should be calibrated for optimal performance of the
sensors. This should be done just before a calibration verification. A convenient time
may be when the UV lamp is changed after 4,000 hours.

The resistor set used for this calibration is designated Part No. 139-005 (139-007 for
–SX models) and is available from Mettler-Toledo Thornton, Inc. The set consists of
the following assemblies:

139-005 Resistor Set

1 each Assembly A: 4 KΩ + 100 KΩ
1 each Assembly B: 4 KΩ + 100 KΩ

1 each Assembly C: Jumper
1 each Assembly D: 2 MΩ + 100 KΩ

1 each Assembly E: 1000 pF, 2MΩ + 100 KΩ

CALIBRATION 29

Stop the measurement and remove the top cover.
CAUTION: POWER IS LIVE DURING THIS PROCEDURE. Press Menus and select

12. MAINTENANCE using the NEXT and UP/DOWN keys. Press ENTER and change
pass word (Factory default is 0000) using the UP key. Press ENTER and select 4.
Board Calib in MAINTENANCE 2/4.

MAINTENANCE 2/4
*4. Board Calib.

5. Sensor Calib.

6. TOC Calib

Press ENTER ↓

BOARD CALIBRATION
S1S2 øR KR TH
S3 øR MR C TH
OPEN Prs Enter ESC

Press ESC to terminate this procedure and return to the Title Screen. To proceed,
disconnect the Sensor 1 and Sensor 2 cables from the board (see Figure 1).

Figure 1

(Printed Circuit Board)

MΩ (S3)

IN (S1)

OUT (S2)

After disconnecting S1 and S2 from the board, push ENTER, resulting in these
displays:

BOARD CALIBRATION
S1S2 ∅R KR TH
S3 ∅R MR C TH

Calibration Doing

BOARD CALIBRATION
S1S2 ∅Rc KR TH
S3 ∅R MR C TH

R 4K Press Enter

Plug one each of Assembly A and B into the connectors of S1 & S2 (see Figure 2).

30 CALIBRATION

Figure 2

(Printed Circuit Board)

MΩ (S3)

4 kΩ

100 kΩ

Assembly A and B

IN (S1)

OUT (S2)

After inserting the resistor assemblies as shown above, press ENTER to result in these
displays:

BOARD CALIBRATION
S1S2 ∅Rc KR TH
S3 ∅R MR C TH

Calibration Doing

BOARD CALIBRATION
S1S2 ∅Rc KRc TH
S3 ∅R MR C TH

R 100K Press Enter

!

Press ENTER again:

BOARD CALIBRATION
S1S2 ∅Rc KRc TH
S3 ∅R MR C TH

Calibration Doing

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅R

Short Press Enter

!

MR C TH

Remove the Resistor Assemblies from S1 and S2 as well as the sensor cable
connector for S3. Insert Assembly C into the connector for S3 (see Figure 3).

Figure 3

Printed Circuit Board

Assembly C

Press ENTER resulting in th e following display:

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅R MR C TH

Calibration Doing

CALIBRATION 31

MΩ (S3)

IN (S1)

OUT (S2)

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MR

R 2M Press Enter

■

C TH

Remove Assembly C from the S3 connection and replace with Assembly D
(see Figure 4):
Figure 4

(Printed Circuit Board)

MΩ (S3)

2 MΩ

100 kΩ

Assembly D

IN (S1)

OUT (S2)

Press ENTER resulting in th e following display:

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MR C TH

Calibration Doing

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MRc C TH

2M + 1000p Press Enter

Replace Assembly D with Assembly E, which includes a capacitor (see Figure 5):
Figure 5

1000 pF, 2 MΩ
100 kΩ

Press ENTER, for the following displays:

BOARDR CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MRc C TH

Calibration Doing

(Printed Circuit Board)

MΩ (S3)

IN (S1)

OUT (S2)

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅R MRc Cc TH

R 100K Press Enter

■

32 CALIBRATION

Press ENTER again for the following displays:

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MRc Cc TH

Calibration Doing

BOARD CALIBRATION
S1S2 ∅Rc KRc THc
S3 ∅Rc MRc Cc THc

Calib END Press SAVE

Press SAVE:Toggle to “YES”. Press ENTER
Press ESC Twice.

THORNTON
550 TOC Analyzer
Ver x.xx

Remove Assembly E.
Push the sensor connectors back into the plugs on the board. Replace top cover.

Push START to resume measurement.

MEASUREMENT VERIFICATION/CALIBRATION

Periodically, the performance of the Analyzer should be verified. It is recommended
that factory trained and qualified personnel perform these services. Typically
calibrations are performed at the Factory, however on-site service may also be provided
in some cases (consult the Thornton Technical Services for details).

Typically the verification procedure is performed at the time of the UV lamp
replacement. Refer to MAINTENANCE for the procedure for lamp replacement.

Before performing the TOC Verification/Calibration, it is advisable to do a board level
calibration followed by a resistivity/temperature sensor verification/calibration. The
board level calibration procedure uses resistor sets which are plugged into the sensor
sockets on the main board. The procedure for board calibration follows in the next
section. The required resistor set, Part No. 139-005, is available from Mettler-Toledo
Thornton.

The resistivity/temperature sensor verification/calibration, which is performed after the
board level calibration, can be best obtained using the values from a recently calibrated
resistivity monitor and sensor, such as the Thornton 770MAX system. The measuring
point of the 770MAX should be close to the connection point for the Thornton 550.

TOC verification/calibration can be performed a number of ways. One method of
verification is to install a calibrated 550 TOC analyzer in parallel with the test unit.
The results of TOC, Resistivity, and Temperature are compared over a period of time.
If the results from the test unit compare favorably with the calibrated 550 TOC unit,
within published operating tolerances, the test unit calibration is verified.

CALIBRATION 33

A second, more extensive TOC calibration, subjects the test unit to a known TOC level.
A sample is prepared by adding some suitable reagent into low TOC water, to prepare
a sample with known TOC level.

Run the calibration sample through the unit until stable readings are achieved. The
instrument value can be adjusted in the following manner.

In the second screen of MAINTENANCE Mode, select 6. TOC Calib.

MAINTENANCE 2/4

4. Board Calib

5. Sensor Calib
*6. TOC Calib

Press ENTER

TOC Calibration
T 2.85 -> 2.85*
R 18.10 -> 18.10
T.F. = 1.000 R.F. = 1.000

Select T, and enter the known value of TOC. The processor will compare this to the
instrument value and calculate a T.F. (TOC Factor), which is a multiplier, and adjust the
instrument reading to conform to the known value.

34 CALIBRATION

CHAPTER 8: ADVANCED CONFIGURATION

ADVANCED START UP METHODS

The CONFIGURATION and OPERATION methods described previously should be
adequate for pure and ultrapure waters (resistivity generally in the 10-18 MΩ-cm range)

with relatively low levels of TOC. However, at higher levels of TOC, such as
encountered in some Reverse Osmosis product water, recycle, and reclaim rinse water,
an advanced configuration technique may be necessary for proper operation.

The indication that the standard procedure may need modification is if the “System
Check” results in a display “SYSTEM CHECK FAILED” rather than advancing to the UV
lamp stabilization stage.

The purpose of the System Check sequence is to zero out any differences between
Sensor 1 and Sensor 2, before the UV oxidation process begins.

After the START key is pressed, the system waits for one minute and then examines
the absolute difference between the S1 and S2 conductivity readings. If that absolute
value is less than Calib No. 1 value (SEE TABLE ON NEXT PAGE), the display will
read “System Check OK”. If the difference is not less than Calib No., the system will
wait 20 seconds and read the measurement again. If necessary, this step will be
repeated a third time.

If the System Check is still not OK, the system adopts Calib No. 2 (SEE TABLE ON
NEXT PAGE) as the acceptable criterion. It will check up to five times with 20 seconds
between attempts.

Note: These two calibration values can be seen in the 2nd
screen of the ‘Other Setup’ menus:

Press Menus and select item 12. MAINTENANCE by pressing the NEXT and DOWN
keys.

Press ENTER, then enter the Password, (Factory default is 0000) using the UP and
ENTER keys, the first screen, MAINTENANCE 1 / 4, will display. Use the NEXT button
to reach the fourth Maintenance Screen 4/4. Using the DOWN/UP keys, select Item

11.Other Setup.

Press ENTER. The ‘Other Setup’ WRITE OFF/ON screen will appear on the display.

9. CALENDAR SETUP

10. SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. *MAINTENANCE

MAINTENANCE 4/4

10. A/D View
*11. Other Setup

ADVANCED CONFIGURATION 35

OTHER SETUP

WRITE OFF

NOTE: Changing the W RITE OFF to ON will allow changes to be the factory settings
within the ‘OTHER SETUP’ menu screens. This should only be turned to ON if
changes are being made.

Using the NEXT key select INITIALIZE CHANGE screen.

2.INITIALIZE CHANGE
Calib. No. 1 *0010
Calib. No. 2 0050

The Table below shows the Calib. Numbers for each 550 model. Values are in units of
µS/cm, these values are factory set and should not be altered as instrument

performance may be affected.

550

55-HT 550-SX
Calib. No.1 0010 0010 0006
Calib. No.2 0050 0550 0010

If the System Check fails after five tries, the processor reads the value of S3, which
measures the resistivity of the incoming water sample. If the reading of S3 indicates

the incoming water is less than 10 MΩ-cm but greater than 0.05 MΩ-cm (<20 µS/cm),
the processor will set the absolute value of the difference between S1 and S2 to zero.
The System Check will be indicated as “PASSED”. The UV lamp is automatically
turned on and allowed to stabilize for approximately 2 minutes. The system then starts
measuring and indicating TOC.

If the resistivity of the incoming water is <0.05 MΩ-cm (conductivity >20µS/cm), the
display will indicate “System Check Failed”. Error 2 is activated, and the unit will not
measure TOC. This error indication can be disabled on the 4

th

screen of OTHER

SETUP menus.

4.MEASURE PARA 2
RESERVE2 0000
RESERVE3 1000
Sensor Status *0000

• Select Sensor Status using the DOWN key. Press ENTER

• Using the UP key change Sensor Status from 0000 to 1000 to disable Error 2.

• Press Save to write this change to the EEPROM.

• Press ESC to return the display to the TITLE screen.

• Press START, and after the System Check sequence, the unit will measure and

display TOC.

36 ADVANCED CONFIGURATION

If the resistivity of the incoming water is 10 MΩ-cm or above, the System Check not
passing indicates there is a problem, and the screen will display “SYSTEM CHECK
FAILED.” If this occurs, turn the unit off , then on again, and push the START button to
once again initiate the System Check sequence. If the System Check again fails, the
“System Check FAILED” can be overridden by changing the RESERVE2 in the
MEASURE PARA 2 (4th screen in OTHER SETUP menus) as follows:

4.MEASURE PARA 2
RESERVE2 *0000
RESERVE3 1000
Sensor Status 0000

Select RESERVE2 using UP/DOWN key and press ENTER. Change from XX0X
Normal System Check to XX1X Special System Check using the NEXT and UP keys.
This will override “SYSTEM CHECK FAILED” and permit the sequence to advance to
the next stage (turn on UV lamp.)

This means that the difference between the zero readings of S1 and S2 will not be
eliminated and there may be some error in the measured TOC value. This error is

usually insignificant in lower quality water (<10 MΩ-cm.)

VIEWING SENSORS

To view the readings of the individual sensors, press Menus and select 12.
MAINTENANCE using the NEXT and UP/DOWN keys.

Press ENTER, enter the Password, (Factory default is 0000), using the UP and ENTER
keys, the first screen, MAINTENANCE 1/4, will display. Using the DOWN/UP keys,
select Item 2. Sensor View and press ENTER.

9. CALENDER SETUP
10 SYSTEM SETUP1

11. SYSTEM SETUP2

12. *MAINTENANCE

MAINTENANCE 1/4

1. Demo Mode On/Off
*2. Sensor View

3. EEPROM Setup

ADVANCED CONFIGURATION 37

Sensor View 1/4
S1 1.53652 23.75
S2 7.39979 23.35
S3 0.91 23.73

This first screen, Sensor View 1/4, shows
temperature-compensated conductivity and
temperature readings for S1 and S2 (resistivity
for S3).

Press Next ↓↓↓↓

Sensor View 2/4
[S1] 1.49524
[S2] 5.75341
[S3] 0.93

Press Next. The second screen shows raw
values (not temperature-compensated) of
conductivity and resistivity.

Press Next ↓↓↓↓

Sensor View 3/4
TOC CURVE 01
TOC = 82.32
Delta = 5.86327

Press Next. The third screen indicates the TOC
Curve presently in use, the TOC reading and
the difference between S1 and S2.

Press Next ↓↓↓↓

Sensor View 4/4
Now D = 5.86327
Init D = 0.00008
PPB set = *0000

“Now D” – “Init D” = Difference that is
converted to TOC.
PPB set : Not used

In the Sensor View area, it is possible to observe measurements in both the
non-oxidizing mode (UV Lamp Off) and in the oxidizing mode (UV Lamp ON). First, the
unit must be placed in the non-measuring (Standby) mode by pushing the
START/STOP button, which turns off the UV lamp and returns the display to the TITLE
screen. Once in non-measuring (Standby) mode, return to the Sensor View area in
SETUP, as described above.

After sufficient time (about 2 minutes) has been allowed for the UV lamp to stabilize, the
delta conductivity in the non-measuring mode (STAND BY) can be observed. This
information would be requested in event of a problem where troubleshooting is
required.

CAUTION: PRESSING THE MENUS KEY WHILE IN SENSOR VIEW, W ILL T URN ON
THE UV LAMP. THIS FUNCION EXISTS AS A MAINTENANCE TOOL AND IS
INTENDED FOR USE BY AUTHORIZED THORNTON SERVICE PERSONNEL ONLY.

TOC CURVE

In Sensor View screen 3 / 4, the display shows the TOC Curve designation used to
determine the TOC value measured by the analyzer. The factory default for all three
models, 550/550-HT/550-SX is TOC Curve1

This curve is designed to provide optimum performance for typical sample waters that
meet the water quality and TOC range limits specified for these analyzers.

38 ADVANCED CONFIGURATION

In certain circumstances, this Factory default may be changed. These are special
cases where a sample water may contain known levels of specific organics, in which
case a different curve designation may be entered. This alteration will require factory
support and should only be performed by factory trained and certified personnel.

ADVANCED CONFIGURATION 39

APPENDIX A

KEY/DISPLAY FUNCTIONS

MODE
KEY

MAJOR

FUNCTION

FUNCTION

WHEN UNIT IS

MEASURING TOC

FUNCTION

WHEN UNIT IS IN

STANDBY

FUNCTION

WITHIN ITEM 12.

MAINTENANCE

MENUS

START/
STOP

MENUS

NEXT

SAVE

ENTER

Start or Stop
Measuring TOC

Push to enter setup
& configuration
Menus

Scrolls the menu
displays or moves
the Underline to the
next location

Saves changes
made within menu
screens

Allows access to or
exit from the menu
lines and/or selected
items.

Stop Measuring
TOC

Push to enter setup
& configuration
Menus

Press Once,
Displays the
history,Press twice,
displays alarm set
points of a
parameter. Total UV
light time, TF, and
RF

Saves changes
made within menu
screens

Start Measuring
TOC

Push to enter setup
& configuration
Menus

Moves the menu

- Turns UV lamp
on/off in sensor view

- Shows sensor view
from sensor calib.
screen

display down/ move
cursor

Saves changes
made within menu
screens

Allows access to or
exit from the menu
lines and/or selected
items.

UP

DOWN

ESC

1. Selects an item
(denoted by an *)

2. Increase a
number

1. Selects an item

(denoted by an *)

2. Decrease a

number

Backs out of current
menu screen

40 APPENDIX

To read data in
Data History

To read data in
Data History

Escapes back to
Measurement Mode

Moves the (*) within

the menus or
Increases a number

Moves the (*) within

the menus or
Decreases a
number

Backs out of current

menu screen

(

(

SYSTEM CHECK SEQUENCE

Push START key

Wait 3 mi n utes to

stabilize S2-S1 value

Push Start/stop Key

and Enter Key

Simultaneously

Sets |S1-S2| = 0

|S1-S2| < CalibNo .1

See Table in Chap 8)

Wait for 1 minute

Check 3 Times

|S1-S2| < CalibNo.2

See Table in Chap 8)

Wait for 1 minute

NO

NO

YES

YES

SYSTEM CHECK PASS

UV ON

Wait for 2 minutes

TOC measurement displayed

Check 5 Times

APPENDIX 41

NO

SYSTEM

CHECK...FAILED!!

550 OPERATION CHART - Measurement Mode

MEASUREMENT MODE

Flowchart shows Start-up (System Check) sequence and menu screens

available during Measurement Mode

THORNTON
550 TOC Analyzer
Ver x.xx

MENUS Key

PRESS

To Main Menus page

SYS CHECK...FAILED !!
Push “ Stop” key

Alarm Setpoint Screen

ALM1 =450.5 ppb
ALM2 = 10.3 Mohm
TF = 1.234 RF = 0.987
UV TIME = 200 Hours

Read Only: Values
cannot be changed in
this d isp lay

NEXT

Calibration

System

Check

Measurement

Result

NEXT

SYSTEM CHECK
Please Wait

RESIST = 18.20 MΩ-cm

SYS CHECK...PASSED
UV WARMING UP

RESIST = 18.20 MΩ-cm

TOC = 200.32ppb
RES = 18.21 MΩ-cm

TMP = 25.6°C

ESC

Measurement Trend

TIME T OC RE S TP
10:30 75.25 18.20 25.0

NEXT

ENTER

11:00 78.38 17.69 25.1
11:30 79.54 17.25 25.3

ENTER

START/STOP

Please Wait

NEXT

Setup Parameter Select
UP Key (Parameter Select)
DOWN Key (Param eter Select)
NEXT Key (Parameter Select or Page Down)
ENTER Key (Enter after each
Parameter Select)

TOC = 200.32 ppb
RES = 18.21 MΩ-cm

TMP = 25.6°C
ALM1 H UV

ERROR 16

TMP1 OVER

Indication of Alarm,
or UV replacement

When an error occurs
during measurement,
these two screens
alternate

Indication o f Erro r

Measurement Trend Check Mode

TIME TOC RE S TP
10:30* 75.25 18.20 25.0
11:00* 78.38 17.69 25.1
11:30* 79.54 17.25 25.3

42 APPENDIX

Push E NTER Key to indicate *** a fter the
TIME. T h en v iew th e pa st re co rd of
measurement values with UP/DOWN Keys.

A

A

A

A

A

A

(

)

550 OPERATION CHART - Setup Mode

Back to Measurement Mode or Title Screen

(press ESC ke y onc e)

SETUP MODE

From Measurement Mode or Title Screen

Setup

Main menus screen 1/3

1. *ALARM-1 M OD E

2. ALARM-2 MODE

3. ALARM VALUE

4. ALARM DELAY

ENTER

ALARM-1 MODE

ITEM = *ppb
RELAY = High On
HIS T . = 0 0

ALARM-2 MODE
ITEM = *ppb
RELAY = Low On
HIS T . = 0 0

ALARM VALUE
Alm 1 = *100.0ppb
Alm 2 = 018.0Mohm

A1 P Hon A2 M L o n

Up Key....................Nu merical Ch ange

DOWN Ke y ........ ......N u merical C h a n g e

NE XT Key.............Move the Cursor

EN T ER Key ...........C o n f irm the Se t

N u merical Va lu e

lar m 1 Setu p

Item = Chooses parameter to alarm on.
Relay = Activation state when setpoint is
reached.
HIST. = Histeresis

lar m 2 Setu p

Item = Chooses parameter to alarm on.
Relay = Activation state when setpoint is
reached.
HIST. = Histeresis

lar m Value

Configures Setpoint values
Designates what alarm, parameter s and
what mode the activated alarm is
configured to.

Main Menus screen 2/3

5. *PRINT SETUP

6. ANALOG SETUP

7. ANALOG CALIB.

8. UV TIME

Main Menus screen 3/3

For Service

9. Calendar Setup

10. *SYSTEM CONFIG 1

11. SYSTEM CONFIG 2

12. MAINTENANCE

To Maintenance Menu

screens 1/4 thru 4/4

see next page

ESC

ENTER

ESC

ENTER

ALARM DELAY
Alm1 = *00 sec
Alm2 = 00 se c

PRINT SETUP

Print Tim e = *01 min
Hitory W r t = OFF
Nr. of Data = 0100

ANALOG SETUP

Output = *ppb

4mA Lm t = 000.0
20mA Lm t = 100.0

ANALOG CALIB.

4mA LO W = *1000
20mA H I = 1000
HO L D = 00

UV TIME
UV TIME = 2000
UV TOTA L = 04251

CALENDAR SETUP
yy/mm/dd *2003/06/03

hh/mm/ss 11:31:46

SYSTEM CONFIG 1
Sys Nam e *1000

Print-T Unit min
Program Ver 1.xx

SYSTEM CONFIG 2
Auto Start * OFF
Print SYS Conf OFF
Histo ry Clea r OFF

larm Delay

Number of seconds before alarm
triggers relay activation

Print Setup

Configures time interval for data pt collection
For writing data pts to printer

Determines the number of data pts for History
Write function

nalog Setup

For assigning measurement parameter
And values of 4 and 20 mA signal
See Configuration.

nalog Output Calibration

Fro 4-20mA Output calibration
SEE Chapter 2. Installation
For output and loop calibration

UV Time

Time of operation of present UV lamp
Total operating time of Analyzer

Calendar Setup

Set Date and Time.
See Configuration.

System Configuration 1

System name. See C onfiguration.
Pr in t er tim e interv al in se c/min / h r

Current Software version loaded.

System Configuration 2

If ON, meas. begins when power applied.
Toggle ON to print out configuration data.
Toggle ON to clear trend history.

APPENDIX 43

N

N

N

N

N

N

N

N

550 OPERATION CHART - Setup Mode (Maintenance menus)

Back to Measurem en t Mo de o r Title Screen (Press ESC key twice)

To MAIN MENUS SCREEN

From MAIN MENU SCREEN 3/3

Password Input

Password Inpu t
Password 0000
(0000 is Factory Default)

MAINTENANCE MODE

Playing Demo
DEMO Mark OFF

MAINTENANCE 1/4

1. Demo Mode On/Off

2. Sensor View

3. EEPROM Reset

MAINTENANCE 2/4

*4. Board Calib.

5. Sensor Calib.

6. TOC Calib.

MAINTENANCE 3/4

*7. Lock Out

8. Pass Word Change

9. LCD Contrast

Sensor View 1/4
S1 1.53652 23.75
S2 1.50887 23.35
S3 0.91 23.73

EXT KEY

EEPRON Reset
EEPROM Write ON
Sure ??

ENTER K EY

If do, Press Enter key

BOARD CALIBRATION
S1S2 0R KR TH
S3 0R MR C TH
OPEN Prs Enter ESC

Cell 1 IN
Type *0000
R. Const 1000

TH. Const 1000

TOC Cal ib ration
T 2.85→ 2.85∗
R 18.10→ 18.10
T.F= 1.000 R.F= 1.000

Menus Key Lock Out

Menus” Ke y Lo ck Out
Lock Out OFF

EXT KEY

Sensor View 2/4
[S1] 1.49524
[S2] 1.46909
[S3] 0.93

EXT KEY

Cell 2 OUT
Type *0000
R. Const 1000
TH. Const 1000

Next Key

Factory or Service Use ONLY

EXT KEY

EXT KEY

Sensor View 3/4
TOC CURVE 1
TOC = 82.32
Delta = 5.86352

Sensor View 4/4

ow D = 0.56854
Init D = 0.00008
PPb set = *0000

Cell 3 Mohm
Type *0000
R. Const 1000
TH. Const 1000

EXT KEY

Password Changes

ew Password 0000

MAINTENANCE 4/4
*10. A/D View

11. Other Setup

ESC Key

USER SETUP

44 APPENDIX

ESC Key

LCD Contrast
Contrast 1000

A/D Converter
Level 1 1/16

1.23146

Other Setup
Write OFF

550 OPERATION CHART - Maintenance Mode (Other Setup menus)

Back to Measurement Mode

(Press ESC key three times)

Other Setup Menus

From previous page

1. TOC Curve
TOC Curve
FLOW Rate 20

Full Oxidation

2. INITIALIZE CHANGE
Calib. No.1 *0010
Calib. No.2 0050

3. MEASURE PARA 1
Mohm Limitor 1820
RESERVE 1 0000

4. MEASURE PARA 2
RESERVE 2 0000
RESERVE 3 1000
Sensor Status 0000

5. UV TIME
UV ON TIME = *0020
UV CHG TIME = 4000
UV TIME CLR = OFF

*01

NEXT

NEXT

NEXT

NEXT

TOC Curve configuration

Initialize Limit Se tu p

(For Factory or Service use only

The Calib No.1&2 number is read as 0.010 µS/cm.
See Table in Chapter 8.
Programmed TOC Curve.

Measurement Parameter 1

Designates MΩ-cm limit value on display.
Reserve not used.
To change flow rate, see CONFIGURATION

Measurement Parameter 2

Multi-functional. See ADVANC ED CONFIGURATION.
Not us ed.
For enabling or disabling Error 2, see ADVANCED
CONFIGURATION.

UV Light Time

ON TIME: total hrs present lamp has been on.
CHG TIME: recommended limit for lamp.
TIME CLR: Sets On Time to zero.

6. TOC OFFSET
TOC OFFSET *0000

NEXT

NEXT

TOC OFFSET

For Factory or Service use only.

APPENDIX 45

OPTIONAL PRINTER DIP SWITCH SETTINGS

Dip Switch Settings for optional Printer model: Seiko DPU414
Software DIP SW1:

Switch

No.

1
2
3
4
5

DIP SW setting command

6
7
8

Software DIP SW2:

Switch

No.

1
2

User-Defined Characters

3
4
5
6
7
8

International Character Set
International Character Set
International Character Set
International Character Set

Software DIP SW3:

Switch

No.

1
2
3
4
5
6
7
8

Function Setting Meaning

Input Method

Printing Speed

Auto loading

CR function

OFF

ON
ON

OFF

ON

Print Density
Print Density
Print Density

OFF

ON
ON

Function Setting Meaning

Print Mode

ON
ON

back-up

Character type

Zero Font

ON
ON
ON
ON
ON

OFF

Function Setting Meaning

Data Bit length

Parity permission

Parity condition

Flow control

Baud Rate
Baud Rate
Baud Rate
Baud Rate

ON
ON
ON
ON

OFF

ON
ON
ON

Serial

High

On

Carriage return

Enable

100%
100%
100%

Normal Printing (40

Columns)

On

Ordinary Characters

0
American
American
American
American

8 Bit

Without

Odd

H/W BUSY

9600 bps
9600 bps
9600 bps
9600 bps

46 APPENDIX

SPECIFICATIONS

Ambient Temp/Humidity
Location
Display

Analog outputs
Outputs Alarm outputs

Alarms displayed
Voltage / Current
Size
Weight
Sample connections
Wetted Parts
Printer
Print out
Printer interval
Power

Industrial Environment (Indoor)

LCD with back-light, displays TOC, resistivity, temperature, and operation/error

One 4-20mA DC, Output is selectable for TOC or resistivity or temperature

UV lamp replacement Alarm; Error Alarm (both on LCD)

100-240 VAC @ 50 / 60 Hz/50W (max)

12.8” (327 mm) W x 6.6” (167 mm) H x 13.8” (350 mm) D

17.6 lb. (8 kg)
316 SS, PVDF, high quality quartz glass

Thermal, Serial dot (SEIKO Model: DPU414)

TOC, Resistivity, Temperature, Date and Time

1-99 seconds, 1-99 minutes, 1-99 hours (adjustable in increments of 1)

6 VDC (provided by analyzer)

TOC Performance
Model

Designation 550 550-HT 550-SX

Measurement 0.1-1000 ppb 0.1-1000 ppb 0.05-30 ppb
Range Repeatability ± 0.1 ppb< 10 ppb TOC ± 0.1 ppb< 10 ppb TOC ±0.05ppb<5ppb TOC
± 1% > 10 ppb TOC ± 1% > 10 ppb TOC ± 1% > 5 ppb TOC

Resolution 0.01 ppb 0.01 ppb 0.001 ppb
Detection Limit 0.1 ppb 0.1 ppb 0.05 ppb

Linearity (Accuracy)* 1.00 ± 0.05 1.00 ± 0.05 1.00 ± 0.05
Water Quality** > 0.5 MΩ-cm > 0.5 MΩ-cm > 10 MΩ -cm
< 2.0 µS/cm < 2.0 µS/cm
Resistivity/ 0.05-18.2 MΩ -cm 0.05-18.2 MΩ -cm 5.0-18.2 MΩ-cm
Conductivity*** (0.055-20 µS/cm) (0.055-20 µS/cm)

Sample Water

Temperature 15-50° 15-90° 15-40°
Particle Size < 100 µm < 100 µm < 100 µm

Flow Rate 20 ml/min 20 ml/min 20 ml/min
Pressure 7-100 psi at Inlet 7-100 psi at Inlet 7-100 psi at Inlet

Sample Water

MDL(Min. Detection Limit) 0.1 ppb 0.1 ppb 0.05 ppb
Temperature Accuracy ±0.3°C ±0.3°C ±0.3°C

(RTD in Conductivity sensors)

*Values expressed in term s of Slope, defined as TOC recovered vs. TO C injected based on tests perform ed using
samples of known concentrations of organics.

**Designates sample water quality requirements to meet stated TOC performance specifications shown.
*** Designates range of conductivity measurement only.

5-40 °C / 5-80% RH Non-condensing

indications

Two SPDT contacts for Hi-Alarm, Lo-Alarm and Error Rated 0.4A @ 120VAC,

2.0A @ 30VDC

0.25 in (6 mm) tube fittings

SPECIFICATIONS 47

ACCESSORIES AND REPLACEMENT PARTS

Part No.

139-003 Thermal Printer, Serial Interface, 6VDC

139-005 Resistor Kit, Board Calibration (550 and 552-HT models)
139-007 Resistor Kit, Board Calibration (550-SX model only)
129-010 Replacement UV Lamp, 185 nanometer
129-002 Replacement Power Cord, three-prong, 1.5 m (5 ft) long

Description

(Supplied with power cord, interface cable with connectors and
manufacturers user’s manual.)

48 ACCESSORIES AND REPLACEMENT PARTS

CE DECLARATION OF CONFORMITY

We, Mettler-Toledo Thornton, Inc., 36 Middlesex Turnpike, Bedford, MA 01730 hereby declare, in
conjunction with the original equipment manufacturer that all 550 TOC Analyzers to which this
declaration relates, is in conformity with the following European, harmonized and published
standards at the date of this declaration:

EN 61326 Emissions (EN 55011 Group Class A) and Immunity
IEC 61010-1 Safety (LVD)

This declaration is based on complete test data and technical documentation relating to the tests
performed per above standards, as noted.

CE DECLARATION OF CONFORMITY 49

DECLARATION OF CSA COMPLIANCE

Declaration of CSA Compliance
Mettler-Toledo Thornton, Inc., 36 Middlesex Turnpike, Bedford, MA 01730 hereby declares that all

550 TOC Analyzers are eligible to bear the official CSA Mark, as shown below, with the adjacent
indicators ‘C’ and ‘US’ and a Certificate of Compliance from the Canadian Standards Association
has been issued and is on file.

PRODUCTS

Listed below is the detailed information noted on this certificate.

CLASS 2252-03 PROCESS CONTROL EQUIPMENT
CLASS 2252-83 PROCESS CONTROL EQUIPMENT – Certificate to U.S. Standards

APPLICABLE REQUIREMENTS

CSA Standard C22.2

No. 0-M92 - General Requirements – Canadian Electrical Code, Part II

0.4-M1982 - Bonding and Grounding of Electrical Equipment (Protective Grounding)

1010.1-92 - Safety Requirements of Electrical Equipment for Measurement, Control and

Laboratory Use, Part 1: General Requirements (Includes Amendment 1)

1010.1B-97- Amendment 2 to CAN/CSA-C22.2 No. 1010.1-92, “Safety Requirements
for Electrical Equipment for Measurement, Control, and Laboratory Use,
Part 1: General Requirements”

ANSI/ISA
S82.01-1994- Safety Standards Electrical and Electronic Test, Measuring, Controlling
and Related Equipment – General Requirements
TIL I-29A - Process Control equipment

The ‘C’ and ‘US’ indicators adjacent to the CSA Mark signify that the product has been evaluated
to the applicable CSA and ANSI/UL standards, for use in Canada and the U.S> respectively. This
‘US’ indicator includes products eligible to bear the ‘NRTL’ indicator, i.e. National Recognized
Testing Laboratory, is a designation granted by the U.S. Occupational Safety and Health
Administration (OSHA) to laboratories which have been recognized to perform certification to U.S.
Standards.

50 DECLARATION OF CSA COMPLIANCE

WARRANTY

Mettler-Toledo Thornton, Inc. warrants products it manufactures against defects in materials and
workmanship for 18 months from the date of shipment from Mettler-Toledo Thornton. Some non­Mettler-Toledo Thornton manufactured resale items may have shorter warranties. Mettler-Toledo
Thornton honors only the warranty period of the original manufacturer. Consumable items such as
pH and ORP sensors and TOC UV lamps are warranted for a period of 6 months from shipment
in normal use and service.

Catalog descriptions, although accurate, should not be taken as a guarantee or warranty. Mettler­Toledo Thornton’s obligation under the warranty shall be to repair at its facility or replace any
products which Mettler-Toledo Thornton finds to be defective. Items returned for warranty must be
properly packaged, shipped prepaid and insured, and must be accompanied by a Return
Materials number assigned by Mettler-Toledo Thornton Customer Service. Proper return
packaging for pH, ORP and dissolved oxygen sensors includes their original storage boot,
chamber or alternative packaging containing a small amount of water to keep the sensor tip from
drying out.
Note: Substitution, modification or mis-wiring of cables voids all warranties.

THE ABOVE WARRANTY IS THE ONLY WARRANTY MADE BY METTLER-TOLEDO
THORNTON, INC. AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING, WITHOUT LIMITATION, IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. METTLER-TOLEDO THORNTON SHALL NOT BE
LIABLE FOR ANY LOSS, CLAIM, EXPENSE OR DAMAGE CAUSED BY, CONTRIBUTED TO
OR ARISING OUT OF THE ACTS OR OMISSIONS OF THE BUYER OR THIRD PARTIES,
WHETHER NEGLIGENT OR OTHERWISE. IN NO EVENT SHALL METTLER-TOLEDO
THORNTON’S LIABILITY FOR ANY CAUSE OF ACTION WHATSOEVER EXCEED THE COST
OF THE ITEM GIVING RISE TO THE CLAIM, WHETHER BASED IN CONTRACT, WARRANTY,
IDEMNITY, OR TORT (INCLUDING NEGLIGENCE).

Returned Goods

Contact Mettler-Toledo Thornton Customer Service for a Return Materials Authorization (RMA)
number before any item is returned. Items returned for credit or exchange must be in new,
salable condition and in original packaging. For items being returned up to 90 days there is a
15% restocking charge; from 91 to one year, 25% restocking charge. No returns on custom
and/or special orders.

Mettler-Toledo Thornton, Inc. Toll-Free: 800-510-PURE
36 Middlesex Turnpike Fax: [phone]
Bedford, MA 01730 [e-mail]
[phone] Part 84428

www.thorntoninc.com

Rev. A 11/03