YSI 3100 User Manual

CONDUCTIVITY INSTRUMENT

S

µ

C

YSI Model 3100

Conductivity
Salinity
Temperature
Instrument

Operations
Manual

Table of Contents

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

1.1 Capabilities...................................................................................................................................................... 1

1.2 Controls............................................................................................................................................................ 2

Front Panel...................................................................................................................................................... 2

Rear Panel....................................................................................................................................................... 3

2. Getting Started.........................................................................................................................................4

2.1 Unpacking........................................................................................................................................................ 4

2.2 Warranty Card.................................................................................................................................................. 4

2.3 What You Need ............................................................................................................................................... 4

3. System Configuration and Operation....................................................................................................5

3.1 Turning the Instrument On............................................................................................................................... 5

3.2 Connect the Cell............................................................................................................................................... 5

3.3 Configure the 3100.......................................................................................................................................... 6

Cell Constant .................................................................................................................................................. 6

3.4 Measurement Modes........................................................................................................................................ 7

3.5 Making Measurements..................................................................................................................................... 9

3.6 Autoranging & Range Searching ..................................................................................................................... 9

3.7 Platinization..................................................................................................................................................... 9

4. Advanced Setup.....................................................................................................................................10

4.1 Cell Calibration.............................................................................................................................................. 10

4.2 Temperature Coefficient................................................................................................................................ 12

4.3 Reference Temperature.................................................................................................................................. 12

4.4 Manual Ranging............................................................................................................................................. 13

5. Maintenance...........................................................................................................................................15

5.1 Cell Cleaning and Storage.............................................................................................................................. 15

5.2 Platinization................................................................................................................................................... 15

6. Troubleshooting....................................................................................................................................17

Error Messages............................................................................................................................................. 17

7. Principles of Operation.........................................................................................................................19

7.1 3100 Principles .............................................................................................................................................. 19

7.2 Conductivity Principles.................................................................................................................................. 19

Introduction .................................................................................................................................................. 19

Conductivity Fundamentals .......................................................................................................................... 19

Cell Constant ................................................................................................................................................ 20

Choosing a Conductivity Cell....................................................................................................................... 21

Cell Constant Calculation............................................................................................................................. 22

Conductivity Cell Calibration - Some Things To Remember..................................................................... 22

Conductivity Law..........................................................................................................................................23

Low Conductivity Measurements ................................................................................................................. 23

General Conductivity Measurement Precautions.......................................................................................... 24

Platinization.................................................................................................................................................. 24

Temperature Correction................................................................................................................................ 24

i

Small Sample Measurements ........................................................................................................................ 25

Conductivity System Accuracy Considerations............................................................................................ 26

7.3 Salinity........................................................................................................................................................... 26

7.4 Temperature................................................................................................................................................... 27

7.5 Sources of Errors ........................................................................................................................................... 27

Cell Contamination....................................................................................................................................... 27

Cell Platinizing ............................................................................................................................................. 27

Electrical-Noise Errors ................................................................................................................................. 27

Contact Resistance........................................................................................................................................ 27

Cable Series Resistance and Shunt Capacitance........................................................................................... 28

Galvanic and Miscellaneous Effects ............................................................................................................. 28

8. Warranty & Repair .................................................................................................................................29

8.1 Cleaning Instructions ..................................................................................................................................... 30

8.2 Packing Instructions....................................................................................................................................... 31

8.3 Disassembly/Assembly Procedures................................................................................................................ 32

9. Accessories and Replacement Parts...................................................................................................33

9.1 YSI Conductivity Cells.................................................................................................................................. 34

9.2 Standard Calibrator Solutions........................................................................................................................ 35

10. Required Notice...................................................................................................................................36

11. Appendix A - Specifications ...............................................................................................................37

12. Appendix B - Temperature Correction Data For Typical Solutions................................................38

13. Appendix C - Conversion Factors......................................................................................................42

14. Appendix D - Glossary of Terms........................................................................................................43

ii

1. Introduction

The YSI Model 3100 is a microprocessor based instrument designed to perform laboratory
measurement of conductivity, salinity and temperature. The instrument’s push button operation
makes it simple to use.

The Model 3100's microprocessor allows the system to be easily calibrated with the press of a
few keys. Additionally, the microprocessor performs a self-diagnostic routine each time the
instrument is turned on. The self-diagnostic routine provides you with useful information about
the cell constant, function of the instrument circuitry, and the quality of the readings you obtain.

The system simultaneously displays temperature (in
parameters: conductivity (in µS/cm or mS/cm), temperature compensated conductivity, (in

S/cm or mS/cm), and salinity (in parts per thousand [ppt]). You can switch back and forth from

µ

salinity, conductivity, and temperature compensated conductivity with a single push of the
[

MODE]

The new YSI 3200 series conductivity cells contain internal temperature sensors for temperature
measurement and automatic temperature compensation. The Model 3100 is also compatible with
YSI 3400 series conductivity cells when used with the YSI Model 3232 cell adapter. However
3400 series cells do not contain an internal temperature sensor, therefore, when using a 3400
series cell, temperature measurement, temperature compensation or salinity measurement is not
possible.

key.

o

C), along with one of the following

1.1 Capabilities

• Adjustable reference temperature 15 to 25 °C

• Automatic temperature compensation

• Adjustable temperature compensation factor 0 to 4%/°C

• Adjustable Cell constant, ranges:

0.01, 0.08-0.12, 0.8-1.2, 8-12

• Auto or manual ranging

• Conductivity or Salinity readings

• 7-pin mini DIN connector with thermistor connections

• AC line power

1

1.2 Controls

y

y

Front Panel

The front panel of the instrument contains the display and keypad as shown below.

MODE Key

Power

ON/OFF

3100

12.85

CONDUCTIVITY INSTRUMENT

uS

22.4

°C

Displa

ENTER Ke

UP ARROW

DOWN ARROW

2

The following diagram shows the typical display.

Conductivity:

mS/cm

uS/cm

S

Temperature compensated conductivity:

mS/cm

uS/cm

Salinity:

ppt

10.00

24.8

µ

°C

Temperature: °C

NOTE: Flashing °C symbol
indicates temperature
compensation is enabled.

The [Mode] key is used to select the current display mode. Mode choices are conductivity,
temperature compensated conductivity or salinity. Temperature is always displayed at the bottom
of the screen.

Rear Panel

The rear panel contains the connections for the power supply and cell. It also has a mounting post
for the 3232 adapter as shown below.

Adapter mounting post

@ 100ma

Power Supply Connection

The power supply connection requires a 12 VDC power supply (included) with at least 100 ma
current. The polarity is marked on the instrument.

3

Cell Connection

The connector for the cell is a 7-pin mini DIN connector and is marked with an arrow to show
proper alignment. Be sure to align the arrows when plugging in the cell.

YSI 3200 series cells utilize a mini DIN connector that plugs directly into the 3100. If, however,
you have a YSI 3400 series cell, the YSI 3232 cell adapter will be required. The YSI 3232
adapter mounts on the post on the rear of the 3100. It has a 7-pin mini-DIN connector and two
binding posts. The mini-DIN connector plugs into the 3100 cell socket and a YSI 3400 series cell
(or equivalent) connects to the binding posts.

YSI 3200 series cells contain an internal temperature sensor for temperature measurement,
temperature compensation and salinity. YSI 3400 series cells do not contain an internal
temperature sensor, therefore,

temperature compensation or salinity measurement is not possible

when using a 3400 series cell, temperature measurement,

.

2. Getting Started

2.1 Unpacking

When you unpack your new YSI Model 3100 for the first time, check the packing list to make
sure you have received everything you should have. If there is anything missing or damaged, call
the dealer from whom you purchased the Model 3100. If you do not know which of our
authorized dealers sold the system to you, call YSI Customer Service at 800-765-4974 or 937­767-7241, and we'll be happy to help you.

2.2 Warranty Card

Please complete the Warranty Card and return it to YSI. This will record your purchase of this
instrument in our computer system. Once your purchase is recorded, you will receive prompt,
efficient service in the event any part of your YSI Model 3100 should ever need repair.

2.3 What You Need

Several things are needed in order to make accurate conductivity measurements using the YSI

3100. The following list shows the basic items required.
Instrument

•

Power Supply

•

Conductivity Cell

•

Standard Solution(s)

•

Beakers

•

Rinsing Solution

•

4

3. System Configuration and Operation

3.1 Turning the Instrument On

Plug the power supply into its mating connector on the back of the instrument. Depress
the (on/off) key to turn the instrument on. The instrument will activate all segments of the
display for a few seconds, which will be followed by a self test procedure which will last for
several more seconds. During this power on self test sequence, the instrument’s microprocessor
is verifying that the instrument is working properly. The Model 3100 will display the current cell
constant when the self test is complete.

1.00

CEL

If the instrument detected a problem, the display will show a continuous error message. For a list
of these error messages, see chapter
diagnostic routine, the following screen should be displayed (with no cell connected).

6 Troubleshooting.

0.00

udr

After the instrument completes this

S

µ

°C

Cell constant

3.2 Connect the Cell

Plug the cell (YSI 3200 series) into the connector on the back of the instrument marked cell. YSI
3200 series cells contain an internal temperature sensor for temperature measurement and
compensation.

If you are using a YSI 3400 series cell, you will need the YSI 3232 cell adapter. YSI 3400 series
cells do not contain an internal temperature sensor, therefore,

temperature measurement, temperature compensation or salinity measurement is not
possible

.

5

when using a 3400 series cell,

Conductivity

16.34

S

µ

24.8

°C

Temperature: °C

3.3 Configure the 3100

Before operating the 3100, or whenever you change cells, you
the cell used. You must enter the manufacturer’s stated (or your manually calculated) cell
constant (K) as shown below (
The default configuration is as follows:

Cell constant of K = 1

•

Temperature compensation corrected to 25°C using a coefficient of 1.91%/°C.

•

If you are using a cell with a cell constant of K=1 (such as the YSI 3252, 3253, 3254, 3401,
3403, 3417, or 3445), the cell constant is already set correctly. If, however, you are using a cell
with a different cell constant (such as the YSI 3256, 3255, 3402, 3418, 3440, or 3446), you must
enter the manufacturer’s stated cell constant for the cell that you are using (K= 0.1, 10.0 etc.) as
shown below (

Cell Constant

Follow these steps to change the cell constant.

Cell Constant

Cell Constant).

).

configure the 3100 to match

must

1. With the instrument on, press and release the [

same time. The
of the display will show

2. Press and release the [

value set previously using Advanced Setup).

3. Press and release the [

value set previously using Advanced Setup).

symbol will appear at the bottom left of the display and the large portion

CAL

(or a value set previously using Advanced Setup).

%

1.91

1.91

CAL

MODE

MODE

] key. The larg e portion of the display will show

] key aga in. The la rg e portion of the display will show

DOWN ARROW

%

22.7

6

°C

] and [

MODE

Cal symbol

] keys at the

(or a

25.0C

1.00

(or a

1.00

CAL

Cell constant

4. Use the [

constant.

UP ARROW

] or [

DOWN ARROW

] keys to change the value to the desired new cell

New cell constant

0.10

CAL

5. Press the [

indicate that your change has been accepted. The 3100 will return to normal operation mode.

ENTER]

key. The word “

SAVE

” will flash across the display for a second to

SAVE

3.4 Measurement Modes

The Model 3100 is designed to provide four distinct measurements:

!

Conductivity

!

Temperature Co m pe nsate d Co nduct ivit y

!

Salinity

!

Temperature

NOTE:

When you turn the Model 3100 off, it will “remember” which mode you used last and

will return to that mode the next time the instrument is turned on.

-- A measurement of the conductive material in the liquid sample without regard
to temperature

-- Automatically adjusts the rea ding to a c alc ulate d
value which would have been read if the sample had been at 25
other reference temperature which you choose). See section

.

Setup

-- A calculation done by the instrument electronics, based upon the conductivity and
temperature readings.

-- Always display ed.

NOTE: Requires YSI 3200 series cell.

NOTE: Requires YSI 3200 series cell.

7

o

C (or some

4. Advanced

To choose one of the measurement modes (temperature is always displayed), simply press and
release the [

MODE

] key. Carefully observe the small legends at the far right side of the LCD.

Temperature

Compensated

Conductivity

with °C

If the instrument is reading
display will be followed by either a µS or mS

o

flashing on and off.

C

If the instrument is reading
either a

or

µµµµ

S

but the small portion of the display will show the

mS,

Temperature compensated conductivity,

Conductivity,

10.62

the large numbers on the display will be followed by

24.8

Conductuctivity

with °C

the small portion of the display will show the

and

mS

°C

Salinity
with °C

the large numbers on the

o

C NOT

°C Not flashing = Conductivity
°C Flashing = Temperature compensated

flashing.

conductivity

NOTE: The instrument measures conductivity in uS/cm or mS/cm even though the /cm is

not shown on the display.

If the instrument is reading

NOTE: Temperature compensated conductivity and salinity modes cannot be used unless a

YSI 3200 series cell is connected.

with the 3232 cell adapter, these modes will display an error message (“LErr”) since
3400 series cells do not contain a temperature sensor.

Salinity,

the large numbers on the display will be followed by a

Salinity

ppt

34.2

24.8

When using a YSI 3400 series cell (or equivalent)

°C

ppt.

8

3.5 Making Measurements

After setting up the 3100 instrument and cell as described earlier, the following basic steps
should be used to make measurements.

1. Verify that the 3100 is properly set up to use the current cell by measuring, or calibrating
with, a standard conductivity solution. See section

2. Immerse the cell in the solution to be measured.

3. Gently tap the cell to remove any air bubbles and dip the cell in the solution 2 or 3 times
to ensure proper wetting. The cell electrodes must be submerged and the electrode
chamber must not contain any trapped air. If using a flow through or fill cell, be certain it
is completely full.

4. Allow time for the temperature to stabilize.

4.1 Cell Calibration

.

5. Press the [

6. Rinse the cell with distilled or deionized water.

MODE

] key to select the units required, then read the display.

3.6 Autoranging & Range Searching

The YSI Model 3100 is an autoranging instrument. This means that, regardless of the
conductivity or salinity of the solution (within the specifications of the instrument), all you need
to do to get the most accurate reading is to put the cell in the sample. This feature makes the
Model 3100 as simple as possible to operate.

When you first place the cell into a sample or calibration solution, and again when you first
remove the cell, the instrument will go into a range search mode that may take as long as 5

seconds. During some range searches, the instrument display will flash
movement from one range to another.

rANG

rANG

to indicate its

The length of the range search depends on the number of ranges which must be searched in order
to find the correct range for the sample. During the range search, the instrument will appear to
freeze on a given reading for a few seconds then, once the range is located, will pinpoint the
exact reading on the display. The display may also switch to
range search before it selects the proper range.

During normal operation, the [
instrument. See

4.4 Manual Ranging

ENTER

] key enables and disables the autoranging feature of the

if you need to switch to manual ranging.

for a second or two during a

00.0

3.7 Platinization

The 3100 can be used to replatinize the electrodes of the cell. See section
details.

9

5.2 Platinization

for

4. Advanced Setup

For highest accuracy, the 3100 and cell may be calibrated as a system using standard conductivity
calibration solutions. See the following section,

The default temperature compensation settings of the YSI Model 3100 are appropriate for the
vast majority of measurement applications. However, some measurement applications require
very specific measurement criteria. For that reason, we have made the YSI Model 3100 flexible
to accommodate these “advanced users.”

If, for example, you are using the YSI Model 3100 for a process control application which
requires that the conductivity readings be compensated to 20°C instead of 25°C -- see section,

4.3 Reference Temperature

saline solution, the default temperature coefficient may need to be changed to get the very best
measurement of that specific salt. See section

. Or, if your application involves the measurement of a very specific

4.1 Cell Calibration

4.2 Temperature Coefficient

4.1 Cell Calibration

Prior to calibration of the YSI Model 3100, it is important to remember the following:

The cell constant must be set correctly before calibrating. See section

•

Cell Constant

.

, for details.

.

3.3 Configure the 3100,

•

Always use clean, properly stored, NIST traceable calibration solutions

Standard Calibrator Solutions

calibration procedures, make certain that the level of calibrant buffers is high enough in the
container to cover the electrodes. Gently agitate the cell to remove any bubbles in the
conductivity cell.

Rinse the cell with distilled water (and wipe dry) between changes of calibration solutions.

•

During calibration, allow the cell time to stabilize with regard to temperature (approximately

•

60 seconds) before proceeding with the calibration process. The readings after calibration are
only as good as the calibration itself.

Perform calibration at a temperature as close to 25°C as possible. This will minimize any

•

temperature compensation error.

Follow these steps to perform an accurate calibration of the YSI Model 3100:

1. Select a calibration solution which is most similar to the sample you will be measuring.
For sea water choose a 50mS/cm conductivity standard (YSI 3165 or 3169)

•

For fresh water choose a 1mS/cm conductivity standard (YSI 3161 or 3167)

•

For brackish water choose a 10mS/cm conductivity standard (YSI 3163 or 3168)

•

2. Place at least 3 inches of solution in a clean glass beaker.

). When filling a calibration container prior to performing the

(see section

9.2

3. Insert the cell into the beaker deep enough to completely cover the electrodes. Do not rest the

cell on the bottom of the container -- suspend it above the bottom at least 1/4 inch.

10

4. Gently tap the cell to remove any air bubbles and dip the cell in the solution 2 or 3 times to

ensure proper wetting. If using a flow through or fill cell, be certain it is completely full.

5. Allow at least 60 seconds for the temperature reading to become stable.

6. Press the [

calibrate in as follows:

Temperature compensated conductivity

Conductivity

7. Press and release both the [

The CAL sy mbol will appe ar at the bottom left of the display to indicate that the instrument is now
in Calibration mode.

MODE

] key until the instrument is in the conductivity mode that you want to

(°C symbol flashing): This mode will
automatically compensate the calibration value to
25°C using a coefficient of 1.91%/°C.

(°C symbol NOT flashing): This mode does NOT use temperature

compensation.

UP ARROW

10.12

CAL

] and [

24.3

DOWN ARROW

mS

°C

] keys at the same time.

CAL symbol

8. Use the [
it matches the value of the calibration solution you are using. If you are calibrating in
temperature compensated conductivity mode, enter the value at 25°C. If you are calibrating in
conductivity mode (not temperature compensated), enter the value the calibration solution
should read at the current temperature (see

9. Once the display reads the exact value of the calibration solution being used, press the
[

ENTER

the calibration has been accepted.

The YSI Model 3100 is designed to retain its last calibration permanently. Therefore, there is no
need to calibrate the instrument after power down.

UP ARROW

] key. The word “

] or [

DOWN ARROW

CAL

SAVE”

] key to adjust the reading on the display until

Appendix B

10.00

24.3

will flash across the display for a second indicating that

).

mS

°C

Calibration solution value

11

4.2 Temperature Coefficient

Follow these steps to modify the temperature coefficient of the Model 3100.

1. Press and release the [
symbol will appear at the bottom left of the display and the large portion of the display will

%

show

1.91

2. Use the [
temperature coefficient.

(or a value set previously using Advanced Setup).

UP ARROW

DOWN ARROW

CAL

] or [

DOWN ARROW

CAL

] and [

MODE

1.91

22.7

] key to change the value to the desired new

1.50

22.7

] keys at the same time. The

%

°C

%

°C

Temperature coefficient

CAL symbol

New temperature coefficient

CAL

3. Press the [
indicate that your change has been accepted.

4. Press the [
disappear from the display.

See

Appendix B

ENTER

MODE

for charts of common salt solutions at various temperatures.

] key. The word “SAVE” will flash across the display for a second to

] key two times to return to normal operation; the CAL symbol will

4.3 Reference Temperature

Follow these steps to modify the reference temperature of the Model 3100.

1. Press and release the [

DOWN ARROW]

and [

MODE]

keys at the same time.

%

1.91

°C

CAL symbol

CAL

22.7

12

The

CAL

display will show

symbol will appear at the bottom left of the display and the large portion of the

%

1.91

(or a value set previously using Advanced Setup).

2. Press and release the [
value set previously using Advanced Setup).

3. Use the [
reference temperature (the allowable range is 15°C to 25°C).

UP ARROW

MODE]

] or [

key. The large portion of the display will show

25.0C

22.7

CAL

DOWN ARROW

15.0C

CAL

] key to change the value to the desired new

22.7

(or a

25.0C

Reference temperature

New reference temperature

4. Press the [
that your change has been accepted.

5. Press the [

ENTER

MODE

] key. The word “

] key to return to normal operation.

SAVE

” will flash on the display for a second to indicate

4.4 Manual Ranging

If your application is easier to perform using a manual range that you select, the YSI Model 3100
allows you to turn off the default autoranging feature. While you are making conductivity or
temperature compensated conductivity measurements, simply press and release the [
key. The conductivity units will flash indicating that the instrument is now in a manual range.
Each additional press of the [
until you return again to autoranging. Six pushes of the [
through the five available manual ranges and return the instrument to autoranging.

ENTER

] key will cycle the Model 3100 to a different manual range

] key will cycle the Model 3100

Flashes to indicate
Manual range

10.62

24.8

ENTER

mS

°C

ENTER

]

13

NOTE:

You may see an error message in some manual ranges if the range selected is not

adequate for the sample you are measuring.

rErr

If this happens, simply press and release the [

24.8

ENTER]

mS

°C

key again until a range is selected which

Range error message

is suitable for your sample. If you get lost and don’t know if you’re in a manual range or
autoranging, simply turn the instrument off and back on. The instrument will default to
autoranging when first turned on.

The YSI Model 3100 has five possible ranges. The number of ranges available for use depends
on the current cell constant.

Cell

Constant

K=0.01
K=0.1
K=1
K=10

Range 1

0 - 49.99 µS/cm

√√
√√√
√√√√

Range 2

0 - 499.9 µS/cm

√√√ √

Range 3

0 - 4999 µS/cm

Range 4

0 - 49.99 mS/cm

Range 5

0 - 499.9 mS/cm

NOTE: Cells may be used beyond their normal range, but with instability and/or reduced
accuracy.

14

5. Maintenance

5.1 Cell Cleaning and Storage

The single most important requirement for accurate and reproducible results in conductivity
measurement is a clean cell. A dirty cell will change the conductivity of a solution by
contaminating it.

To clean a conductivity cell:

1. Dip or fill the cell with cleaning solution and agitate for two to three minutes. Any one of

the foaming acid tile cleaners, such as Dow Chemical Bathroom Cleaner, will clean the
cell adequately. When a stronger cleaning preparation is required, use a solution of 1:1
isopropyl alcohol and 10N HCl or Sulfuric Acid or Ethanol or Methanol.

CAUTION:

platinum or gold.

2. Remove the cell from the solution and rinse in several changes of distilled or deionized

water. Inspect the platinum black to see if replatinizing is required.

Storage

Short term: Store conductivity cells in deionized or distilled water. Change the water frequently

to prevent any growth that may cause electrode fouling.

Long term: Rinse thoroughly with deionized or distilled water and store dry. Any cell that has

been stored dry should be soaked in distilled water until the electrodes appear black
before use.

Cells should not be cleaned in aqua regia or in any solution known to etch

5.2 Platinization

The electrodes of YSI 3200 and 3400 Series conductivity cells are coated with platinum black
during manufacturing. This coating is extremely important to cell operation, especially in
solutions of high conductivity.

The cell should be inspected periodically. If the coating appears to be thin or if it is flaking off,
the electrodes should be cleaned, as noted above, and replatinized. Properly maintained
conductivity cells will perform for years without replatinizing.

The 3100 can be used to replatinize the electrodes of the cell. In addition, you will need a 2-oz
bottle of platinizing solution (YSI 3140).

WARNING: Before replatinizing the electrodes of a cell, make sure that the cell is

designed to have a platinum coating on the electrodes.

1. Immerse the cell in the platinizing solution (YSI 3140). Make sure that both electrodes are
submerged.

15

2. Press both the [
display will show “

3. After the platinization process is complete (about 30 minutes), the 3100 will return to normal
mode. Remove the cell from the platinizing solution. If you want to stop the platinization
before 30 minutes have passed, press both the [
time to abort.

4. Thoroughly rinse the cell with distilled or deionized water.

5. Promptly return the platinizing solution to its container.

UP ARROW

PLA”

] and [

flashing, indicating that platinization is in process.

MODE

PLA

] keys at the same time. The large portion of the

UP ARROW

] and [

MODE

] keys at the same

16

6. Troubleshooting

Error Messages

The instrument performs a Power On Self Test each time it is turned on. The following error
messages are provided to facilitate troubleshooting. They appear on the LCD when an error is
detected.

SYMPTOM POSSIBLE CAUSE ACTION

1. Instrument will not turn on

2. Instrument will not calibrate

3. Instrument readings are inaccurate

4. Main Display reads “OVEr”

5. Main Display reads “Undr”

6. Main Display reads “rErr”

7. Main Display reads “PErr”

Power supply

•

Instrument requires service

•

Incorrect calibration procedure

•

Cell needs cleaning

•

Instrument requires service

•

Calibration is required

•

Cell is contaminated

•

Temperature coefficient has been

•

set incorrectly
Reference temperature incorrect

•

Readings are or are not temperature

•

compensated.
Conductivity Reading is ov er

•

range:
>112 uS with K=0.01 cell
>11.2 mS with K=0.1 c e ll
>112 mS with K=1 c e ll
>499.9 mS with K=10 c e ll

Salinity reading is > 80ppt

•

User cell constant cal is over the

•

limit of the current range
User cell constant ca l is unde r the

•

limit of the current range

User has selected manual ranging &

•

sample exceeds selected range
Conductivity reading is over the

•

range of the instr ument: >499.9 mS
Incorrect sequence of key strokes

•

Check power supply and AC outlet

•

Return system for service

•

See

•

4.1 Cell Calibration

See

•

5. Maintenance

Return system for service

•

See

•

4.1 Cell Calibration

See

•

5. Maintenance

See

•

4.2 Temperature Coefficient

See

•

4.3 Reference Tempe ratur e

See

•

3.4 Measurement M ode s

In all cases, check calibration

•

values and procedure; check
Advanced Setup settings.

Set cell constant to correct range.

•

See

3.3 Configure the 3200, Cell

Constant

If each of these is set correctly,

•

return system for service.

Set cell constant to correct range.

•

See

Constant

Recalibrate using k nown good

•

conductivity standa rd. Se e

Calibration.

Follow cell cleaning procedure. See

•

5. Maintenance.

Use the ENTER key to select a

•

higher or lower m a nua l ra ng e , or to
set system to Autorang ing .

Refer to manual sec tion which

•

provides step by s te p pr oc e dure s
for the function you a re a tte mpting.

.

3.3 Configure the 3200, Cell

.

4.1 Cell

17

SYMPTOM POSSIBLE CAUSE ACTION

8. Main Display reads “LErr”

9. Secondary Displa y reads “Err ra”

10. Secondary Displa y reads “Err ro”

11. Secondary Dis play reads “udr”

12. Secondary Displa y reads “ovr”

13. Secondary Display reads “rEr”

In temperature compensated

•

conductivity mode , te mperature
exceeds the values computed using
user defined temperature coefficient
and/or reference temperature.

In cell constant cal m ode ,

•

temperature exceeds the values
computed using use r de f i ne d
temperature coefficient and/or
reference temperature.

The user has selected Temperature

•

Compensated Conductiv ity or
Salinity and the current ce ll doe s
not contain a temper at ure s e ns or.

System has fa iled its RAM test

•

check procedure
System has fa iled its ROM te st

•

check procedure
Current cell does not contai n a

•

temperature s e nsor (s uc h a s Y SI
3400 series).

Temperature is < -5

•

Temperature is > 95

•

Temperature jumper is set to

•

and reading is >199.9

o

F

o

C

o

C

o

o

F

F but < 203

Adjust user def ine d te mperature

•

coefficient (see

Coefficient

temperature (see

Temperature

Use a YSI 3200 serie s ce ll or turn

•

4.2 Temperature

) or reference

4.3 Reference

)

off temperature compensation.

Turn instrument OFF a nd ba ck ON.

•

Return the system for service.

•

Turn instrument OFF a nd ba ck ON.

•

Return the system for service.

•

Use a YSI 3200 series ce ll if

•

temperature readings or
compensation are required

Read solution of higher temperature

•

Replace Cell/Cable assy

•

Return system for service

•

Read solution of lower temperature

•

Replace Cell/Cable assy.

•

Return system for service

•

o

Set jumper to read

•

Return system for service

•

C.

18

7. Principles of Operation

7.1 3100 Principles

The YSI 3100 obtains a conductance value by varying the amplitude of a square-wave current
forced through the cell so that the center-sampled magnitude of the cell voltage for each half­cycle is constant and is equal to a reference voltage. In this condition, the current and
conductance are directly proportional. To convert this conductance value to conductivity, it is
multiplied by the cell constant which has units of reciprocal cm (cm
cell constant is automatically determined (or confirmed) with each deployment of the system
when the calibration procedure is followed. Solutions with conductivities of 1.00, 10.0, 50.0, and

100.0 mS/cm, which have been prepared in accordance with recommendation 56-1981 of the

Organization International De Metrologie Legale (OIML) are available from YSI. The instrument
output is in µS/cm or mS/cm for both conductivity and temperature compensated conductivity.
The multiplication of cell constant times conductance is carried out automatically by the
software.

7.2 Conductivity Principles

Introduction

Conductivity measurements are used in waste water treatment, industry, pharmaceutical, and
military etc. as a measurement of the purity or the condition of a process. Conductivity is used as
a measurement of a solution’s ability to conduct electric current. The ability of a solution to
conduct electric current depends upon ions: their concentration, size, mobility, viscosity, valence
and the temperature of the solution. Inorganic solutions are relatively good conductors. Organic
solutions are poor conductors.

-1

). For most applications, the

Conductivity Fundamentals

Electrical
difference in the electrical potential (V) between its ends (k=I/V), measured in mhos or siemens
(S). Conductance, therefore, is not a specific measurement. Its value is dependent upon the length
of the conductor.
conductor length. For our purposes, conductivity is defined as the conductance in mhos or
siemens measured across the sides of a one centimeter cube of liquid at a specified temperature.

Looking at our electrodes as sides of a cube, it becomes apparent that
the conductance changes as the geometry of the cube changes. If the
cube lengthens with respect to the area of the sides, then the
conductance will decrease. If the area of the sides increases with
respect to the distance between them, then the conductance will
increase. The conductivity, however, will remain the same, regardless
of the geometry, provided that the temperature and composition of the
measured solution remain constant. A factor called the

) relates conductivity to conductance. The cell constant is defined

(K

as the ratio of the

conductance (k)

Conductivity (

distance between the electrodes (d)

is defined as the ratio of the current (I) in a conductor to the

, or specific conductance, is the conductance per unit of

ℵℵℵℵ

)

cell constant

to the

19

area

normal to the current flow (A):

Cell Constant = K =

Therefore, conductivity equals conductance multiplied by the cell constant.

= k K

ℵℵℵℵ

Example: For an observed conductance of 100 micro mhos (100 microsiemens) and a cell

constant of 0.1/cm

= k K

ℵ×

= 100 mho 0.1/ cm
= 10 mho / cm

In SI units, the cell constant K=0.1/cm would become K=10/m, and the same conductivity would
be expressed:

d

A

×

µ

×

µ

= k K

ℵ×

= 100 S 10/ m

= 1 S / m

Cell Constant

The

cell constant (K)

defined as the ratio of the

electrodes (d)
current flow (A).

1.0/cm or greater normally have small, widely-

spaced electrodes, while cells with constants or

0.1/cm or less have larger electrodes that are

closely-spaced.

to the

is used to determine the resistivity or conductivity of a solution. It is

distance between

area normal to the

Cells with constants of

m

µ

×

20

Choosing a Conductivity Cell

Decide which cell will be the most useful for your conditions by considering the conductivity of
the solution you want to measure, the size of the sample and if temperature measurement or
compensation is required.

3252, 3417
3418
3256, 3402

3255, 3446
3401
3440

3253, 3403

3254, 3445

0 0.1 1.0 10 100 1000 µS/cm

1 10 100 1000 mS/cm

Conductivity

The chart above reflects general guidelines. Refer to cell specifications for details.

ERIES CONDUCTIVITY CELLS

3200 S

Dip cells are generally used for routine conductivity
measurements. The 3254 Fill Cell is designed for small
sample or high throughput work. It requires only 5 ml of
sample and can make measurements quickly from one
sample to the next.

The 3255 Flow Cell is designed for in-line conductivity
measurements, such as for ultrapure water systems.

For temperature measurement, temperature
compensation or salinity, use YSI 3200 series cells.

3252 3253 3254 3255 3256

21

Cell Constant Calculation

YSI 3200 and 3400 Series conductivity cells are calibrated to ± 1% of nominal by
means of a YSI transfer standard traceable to OIML Recommendation 56 and NIST.

Anytime the condition of the conductivity cell changes, it is possible that the cell constant has
also changed. Therefore, you should calibrate your system regularly. If you want to manually
calculate your cell constant, measure the conductance of a standard solution and compare with
the theoretical conductivity of the solution. The formula for determining the cell constant is:

K =

ℵ

k

where

The measured conductance (k) and conductivity (ℵ) must either be determined at the same
temperature or corrected to the same temperature for the equation to be valid. One main reason
for cell constant calibration is to increase overall system accuracy.

Conductivity Cell Calibration - Some Things To Remember

K = cell constant in cgs metric units (cm-1)
k = measured conductance in

ℵℵℵℵ

= theoretical conductivity in

µµµµ

mho

µµµµ

mho/cm

1. Rinse the cell and solution container with some calibrator solution before calibration.

2. Prevent contamination of the solution.

3. Minimize evaporation of the solution.

4. Use adequate sample volume.

5. Purge all air from the cell.

6. Allow adequate time for temperature equilibration.

7. Stir the solution slowly.

8. Know the solution temperature accurately; a 1º C temperature error is approximately a

2% error in conductivity.

9. Insure sound electrical connection between the cell and the instrument.

22

Conductivity Law

Solution Instrument Cell

Conductivity Conductance Constant

S/cm or mho/cm = S or mho

mS/cm or mmho/cm = mS or mmho

µµµµ

S/cm or

µµµµ

mho/cm

=

µµµµ

S or

µµµµ

mho

××××
××××
××××

1/cm
1/cm
1/cm

SOLUTION CONDUCTIVITY

CELL CONSTANT =

METER CONDUCTANCE

SOLUTION CONDUCTIVITY

METER CONDUCTANCE =

CELL CONSTANT

Low Conductivity Measurements

When measuring reagent grade water (deionized) or other substances having extremely low
conductivity, it is recommend that a flow-through cell having a constant of 0.1/cm be used for
the best accuracy. If a flow-through cell is not practical, then extraordinary precautions must be
taken in regard to equipment setup, cell cleanliness, electrical interferences, etc. Therefore, when
operating on this range, some instability in the least significant digit is normal and should be
averaged or ignored.

Error Sources

Solution temperature coefficient may be upwards of 7% per °C

•

Absorption of atmospheric CO

•

Platinization ions may leach into the solution from the electrodes

•

Glass ions may leach into the solution from the cell or container

•

Organic substances may leach into the solution if plastic is used

•

Electrical noise

•

Contact resistance

•

Cable series resistance and shunt capacitance

•

Cell series and shunt capacitance

•

Galvanic effects

•

Only the first four are of major concern for typical measurements, although the user should also
be careful to see that cells are clean and maintained in good condition at all times.

may account for 1.3µS/cm at 25°C

2

23

General Conductivity Measurement Precautions

After selecting the proper cell,

observe the followi ng precau tions

to ensure accurate, repeatable

results:

1. The cell must be clean before making any measurements. When working with substances

having low conductivity, extraordinary cleanliness may be required.

2. Soak cells that have been stored dry in deionized water before use.

3. Immerse the cell in the solution deep enough to submerge the vent hole.

4. The electrode chamber should be free of trapped air.

5. The cell should be at least ¼ inch away from any other object, including the walls or

bottom of the solution container.

6. Stirring may be necessary for highest accuracy measurements, especially in low-

conductivity solutions and to achieve good thermal equilibration.

7. If possible, isolate from ground potential the measurement container.

8. Electrical fields and stray currents caused by stirrer motors, heaters, etc., can interfere

with measurements. The user should determine the effects of these and make the
necessary corrections, either by shielding or by disconnecting those units that cause
trouble.

9. Always handle the cell carefully.

10. Always rinse the cell carefully before transferring it from one solution to another.

11. Never store a dirty or contaminated cell.

12. The cells should not be submerged in aqua regia or any solution which might etch or

dissolve gold.

Platinization

Platinum Black Inspection

The electrodes of YSI 3200 and 3400 Series conductivity cells are coated with platinum black
during manufacturing. This coating is extremely important to cell operation, especially in
solutions of high conductivity.

The cell should be inspected periodically. If the coating appears to be thin or if it is flaking off,
the electrodes should be cleaned and replatinized. Properly maintained conductivity cells will
perform for years without replatinizing.

Replatinizing

The 3100 can be used to replatinize a cell that utilizes electrodes coated with platinum. See
section

5.2 Platinization

. You will need a 2-oz bottle of platinizing solution (YSI 3140).

Temperature Correction

By convention, the conductivity of a solution is the conductivity it exhibits at 25°C. The
conductivity of electrolytic solutions varies with temperature, concentration, and composition.

The amount that the conductivity changes with temperature is expressed as a percent

24

change in conductivity for each degree change in temperature (%/
temperature coefficient.

In extreme cases, the temperature coefficient may have a value as high

°°°°

C), which is called the

as 7%/°C. Each conductive ion has a different temperature coefficient.
When practical, control the temperature of the solution to be analyzed. For high precision work

(±1%), maintain the temperature at 25°C ± 0.1°C. For routine lab work, 25°C ± 0.5°C may be
acceptable. (Ref: ASTM D1125-82

)

Water

Standard Methods of Test for Electrical Conductivity of

When sample temperature control is not practical, use temperature correction to determine the
conductivity at 25°C. The temperature coefficient of your sample can be determined either from
published data or from measurements of representative samples. This coefficient may then be
applied to correct future measurements on samples of similar composition. If sample
composition changes appreciably, the coefficient should be redetermined.

Once the temperature coefficient is known, the conductivity at 25°C can be manually determined
from the following equation:

ℵ

ℵ

=

25

1 + (T - 25)

T

α

where

T = temperature of sample

ℵℵℵℵ
ℵℵℵℵ
αααα

= conductivity at 25

25

= conductivity at measurement temperature T

T

= temperature coefficient of the conductivity solution

°°°°

C

Determining The Temperature Coefficient

You can determine the linear temperature correction coefficient of a solution by measuring its
conductivity at different temperatures using the following equation:

ℵℵ

-

T25

ℵ

(T - 25)

25

where

T = temperature of sample

ℵℵℵℵ
ℵℵℵℵ
αααα

= conductivity at 25

25

= conductivity at measurement temperature T

T

= temperature coefficient of the conductivity solution

°°°°

C

α

=

Small Sample Measurements

It is not always possible to immerse the conductivity cell in a solution for measurements. If the
quantity of solution is not sufficient for a proper measurement with a dip cell, a sample must be
removed for assay. For this application, use the 3254 fill cell. This cell requires 5 mL of sample.
Alternatively, any 3200 or 3400 Series cell, except the 3418 or 3440, may be inverted and used
as a fill cell.

25

The cell you use for small sample applications depends upon the
quantity of solution available and the conductivity of the
solution. The 3401 cell (K=1.0/cm) requires 15 mL, the 3256
and 3402 cells (K=0.1/cm) require 12 mL, the 3253 and 3403
cells (K=1.0/cm) require 3 mL, and the 3252 and 3417 cells
(K=1.0/cm) require 1 mL of sample.

When a dip cell is used as a fill cell, the cell's vent hole is sealed
and the electrode chamber is inverted and filled with solution,
changing the cell constant (K). The cell will require calibration
after being configured as a fill cell.

Conductivity System Accuracy Considerations

System accuracy for conductivity measurements is equal to the sum of the errors contributed by
the environment and the various components of the measurement setup. These include:

•

Instrument accuracy

•

Cell-constant accuracy

•

Temperature measurement accuracy

Instrument Accuracy

YSI meters are very accurate; however, each instrument and range has its own accuracy
statement and therefore, must be accounted for in the overall accuracy determination.

Cell-Constant Accuracy

YSI cells are warranted to be accurate to within one percent, for more accurate work you should
calibrate the cell to determine the exact cell constant.

Temperature Accuracy

The solution temperature accuracy is the sum of the instrument accuracy plus the temperature
sensor accuracy.

If the conductivity is to be expressed at 25°C, some additional errors will be introduced either by
the instrument's temperature correction electronics or by the mathematics used for the conversion
to 25°C.

7.3 Salinity

Salinity is determined automatically from the Model 3100 conductivity and temperature readings
according to algorithms found in

Wastewater (ed. 1995).

The use of the Practical Salinity Scale 1978 results in values which are
unitless, since the measurements are carried out in reference to the conductivity of standard
seawater at 15°C. However, the unitless salinity values are very close to those determined by the
previously-used method where the mass of dissolved salts in a given mass of water (parts per
thousand) was reported. Hence, the designation "ppt" is reported by the instrument to provide a
more conventional output.

Standard Methods for the Examination of Water and

26

7.4 Temperature

The Model 3100 system utilizes a thermistor of sintered metallic oxide which changes
predictably in resistance with temperature variation. The algorithm for conversion of resistance
to temperature is built-in to the Model 3100 software, and accurate temperature readings in
degrees Celsius or Fahrenheit are provided automatically. No calibration or maintenance of the
temperature sensor is required.

7.5 Sources of Errors

Cell Contamination

This error is usually due to contamination of the cell by some previous solution. Normally this is
in the form of an organic film which reduces the solution-electrode interface conductance.
Follow the cleaning instructions carefully.

An entirely different form of contamination sometimes occurs when cells are stored for long
periods of time wet; alga and other life forms grow on the electrodes. While rare, such deposits
have, on occasion, markedly reduced the effectiveness of the cell by reducing the solution­electrode interface conductance.

Cell Platinizing

Errors can be introduced by cells that have begun to lose their electrode coating of platinum
black when measuring solutions having high conductivity values. The effect of poor platinization
is a loss of linearity and a noticeably large change in conductance from range to range on the
instrument.

When you suspect a problem with the cell platinization, follow the instructions for electrode
inspection and replatinization carefully before attempting any critical measurements.

Electrical-Noise Errors

Electrical noise can be a problem in any measurement range, but will contribute the most error
and be the most difficult to eliminate when using the lowest conductance settings. The noise may
be either line-conducted or radiated or both, and may require revised lead dress, grounding,
shielding, or all three. Often, all that is necessary is to make sure that parallel leads are of equal
length and twisted together.

Contact Resistance

YSI 3200 series cells utilize a 4-wire connection virtually eliminating errors due to contact
resistance.

When using the YSI 3232 cell adapter to connect a 2-wire cell (such as the YSI 3400 series
cells), contact resistance can be a source of error when measuring high conductivity. Lugs should
be clean and free of mechanical distortion. They should fit squarely on terminal posts that are
properly tightened. Leads should also be inspected to verify that no physical damage has occurred
that might degrade electrical contact.

27

Cable Series Resistance and Shunt Capacitance

YSI 3200 series cells utilize a 4-wire connection virtually eliminating errors due to cable
resistance.

The short cables provided as a part of regular cell assemblies will introduce negligible error in
most measurements. However, if longer cables are required or if extraordinary accuracy is
necessary, special precautions may be prudent.

When using the YSI 3232 cell adapter and a 2-wire cell (such as the YSI 3400 series cells) with
solutions having very high conductivity values, a high cable resistance will become a major
source of error unless accounted for. When working with solutions having very low conductivity
values and long cables with large capacitance, such as might be used with a flow-through cells at
remote locations, the large cable capacitance will become a major source of error.

Galvanic and Miscellaneous Effects

In addition to the error sources described above, there is another class of contributors that can be
ignored for all but the most meticulous of laboratory measurements. These errors are always
small and are generally completely masked by the error budget for cell-constant calibration,
instrument accuracy, etc. Examples range from parasitic reactances associated with the solution
container and its proximity to external objects to the minor galvanic effects resulting from oxide
formation or deposition on electrodes. Only trial and error in the actual measurement
environment can be suggested as an approach to reduce such errors. If the reading does not
change as the setup is adjusted, errors due to such factors can be considered too small to see.

28

8. Warranty & Repair

YSI Model 3100 Instrum en t s are warranted for two years f rom date of purchase by the end u s er ag ain s t def ect s i n
materials and work manship. YSI cells and cables are warranted for on e year from date of purchase by the end u s er
against defects in material and w orkmanship. Within the warranty period, YSI will repair or replace, at its sole
discretion, free of charge, any product that YSI determines to be covered by this warranty.

To exercise this warranty, write or call your local YSI representative, or contact YSI Customer Serv ice in Yellow
Springs, Ohio. Send the product and proof of purchase, transportation prepaid, to the Authorized Service C en t er selected
by YSI. Repair or replacement will be made an d the product returned, transportation prepaid. Repaired or replaced
products are warranted for the balance of the original w arranty period, or at least 90 days from date of repair or
replacement.

Limitation of Warranty

This Warranty does not apply to any YSI product damage or f ai lu re caused by (i) failure to install, operat e or u s e t h e
product in accordance with YSI’s written in struction s, (ii) abus e or m isu se of the product, (iii) failu re to m ain tain th e
product in accordance with YSI’s written in struction s or standard industry procedure, (iv) any improper repairs to the
product, (v) use by you of defective or improper com pon en ts or part s in s e rv ici n g or repai rin g the product, or (vi)
modification of the produ ct in an y way not expressly au th orized by YSI.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXP RESSED OR IMPLIED, INCLUDING
ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PART ICULAR PURPOSE. YSI’s
LIABILITY UNDER THIS WARRANTY IS LIMITED TO REPAIR OR REPLACEMENT OF THE PRODUCT,
AND THIS SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR ANY DEFECTIVE PRODUCT
COVERED BY THIS WARRANTY. IN NO EVENT SHALL YSI BE LIABLE FOR ANY SPECIAL, INDIRECT,
INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY DEFECTIVE PRODUCT
COVERED BY THIS WARRANTY.

YSI Authorized Service Centers

Please contact YSI for the nearest authorized service center.

YSI Technical Support •

[e-mail] • www.ysi.com

1725 Brannum Lane • Yellow Springs, OH • 45387 • Phone: [phone] • 800 897-4151 (US)

29

8.1 Cleaning Instructions

NOTE: Before they can be serviced, equipment exposed to biological, radioactive, or toxic
materials must be cleaned and disinfected.

instrument, probe, or other device that has been used with body fluids or tissues, or with waste
water. Radioactive contamination is presumed for any instrument, probe or other device that has
been used near any radioactive source.

If an instrument, probe, or other part is returned or presented for service without a Cleaning
Certificate, and if in our opinion it represents a potential biological or radioactive hazard, our
service personnel reserve the right to withhold service until appropriate cleaning,
decontamination, and certification has been completed. We will contact the sender for
instructions as to the disposition of the equipment. Disposition costs will be the responsibility of
the sender.

When service is required, either at the user's facility or at YSI, the following steps must be taken
to insure the safety of our service personnel.

In a manner appropriate to each device, decontaminate all exposed surfaces, including any

1.

containers. 70% isopropyl alcohol or a solution of 1/4 cup bleach to 1 gallon tap water are
suitable for most disinfecting. Instruments used with waste water may be disinfected with
.5% Lysol if this is more convenient to the user.

Biological contamination is presumed for any

The user shall take normal precautions to prevent radioactive contamination and must use

2.

appropriate decontamination procedures should exposure occur.
If exposure has occurred, the customer must certify that decontamination has been

3.

accomplished and that no radioactivity is detectable by survey equipment.
Any product being returned to the YSI Repair Center, should be packed securely to prevent

4.

damage.
Cleaning must be completed and certified on any product before returning it to YSI.

5.

30

8.2 Packing Instructions

1. Clean and decontaminate items to insure the safety of the handler.

2. Complete and include the Cleaning Certificate.

3. Place the product in a plastic bag to keep out dirt and packing material.

4. Use a large carton, preferably the original, and surround the product completely with packing

material.

5. Insure for the replacement value of the product.

Cleaning Certificate

Organization
Department
Address
City _______________ State ______ Zip
Country __________________ Phone
Model No. of Device ______ Lot Number
Contaminant (if known)
Cleaning Agent(s) used
Radioactive Decontamination Certified?
(Answer only if there has been radioactive exposure)
___ Yes ___ No

Cleaning Certified By

Name Date

31

8.3 Disassembly/Assembly Procedures

NOTE: The following procedure should
only be performed by a qualified service
technician.

Case Disassembly

While applying slight separation force

•

to the front, curved edge of the case near
one corner, use a small straight-blade
screwdriver to release the snap (A) on
the same side.

When that snap releases, keep applying

•

the separation force, and use the
screwdriver to release the front snap (B)
nearest the same corner.

Repeat the procedure on the other

•

corner to release both front and both
side snaps.

Swing the case open slowly, pivoting on

•

the three rear snaps (C) until they
release.

C

A

B

Lay the lower case assembly to the side.

•

PC Board Removal

Gently release the two snaps nearest the front, curved edge of the unit.

•

With the snaps released, lift the front of the board slightly and slide the board out of the rear

•

connector openings.

PC Board Re-installation

Remove the protective covering from the display. DO NOT TOUCH THE FACE OF THE

•

DISPLAY, FINGERPRINTS CANNOT BE EASILY REMOVED.
Slip the connector end of the board into place against the gaskets at the rear of the case, then

•

rotate the board down into position, engaging each snap as you go. Be sure that the switch
extenders line up with the switches.

Inspect the assembly to insure that all board snaps are fully engaged and the board is in the

•

proper position in the case. Turn the assembly over and activate each switch. Be sure you can
hear and feel each switch click as it is pressed.

Case Re-assembly

Hook the three snaps at the rear of the case into place and rotate the lower case into place on

•

the upper case. Make sure all four snaps are fully engaged. Press firmly down on the three
rear snaps to make sure they are completely engaged.

32

9. Accessories and Replacement Parts

YSI Item # D escription Comments

003208 3208 Power Supply, 115 VAC
003209 3209 Power Supply, 240 VAC
031008 Overlay, Window
031009 Overlay, Keypad
051009 Window
113117 Board Assy, PC, Main
055214 LCD Includes zebra strips
113138 Case Assy, Upper
111027 Case Assy, Lower Includes 003226 weight
003226 Weight, SS
051043 Foot, Rubber, Self-Stick
032061 Gasket, Connector, Cell
032063 Gasket, Connector, Power
051025 Standoff, .25, Snap-In Retain display
003228 Extension, Switch
031041 Operations Manual
031043 Service Manual
003229 Cable Assy, Cell 7-pin mini DIN to pigtail
3232 Cell adapter For YSI 3400 Series cells
3166 Calibrator resistor set Requires 3232 cell adapter

33

9.1 YSI Conductivity Cells

YSI 3200 series conductivity cells have a built in temperature sensor for temperature
measurement and automatic temperature compensation. Dip, fill and flow-through conductivity
cells are available, each utilizing platinized platinum iridium electrodes. These cells have the
following specifications:

Part
Number
3200 Series Dip Cells
3252 1.0/cm 100/m ABS

3253 1.0/cm 100/m glass 178 mm 13 mm 10 mm 51 mm
3256 0.1/cm 10/m glass 159 mm 25 mm 21 mm 52 mm
3200 Series Fill Cell
3254 1.0/cm 100/m glass 135 mm 19 mm 11 mm 83 mm
3200 Series Flow-Through Cell
3255 0.1/cm 10/m glass 146 mm 25 mm 21 mm 76 mm

cgs Cell
Constant

SI Cell
Constant

Material Overall

Length

146 mm 13 mm 10 mm 20 mm

plastic

O.D. Chamber

I.D.

Chamber
Depth

YSI also offers 3400 series cells which do not contain temperature sensors. Several dip and flow­through conductivity cells are available, each utilizing platinized platinum iridium electrodes,
except the YSI 3418, which has platinized nickel electrodes.

These cells require the 3232 cell
adapter for use with the YSI 3100 and will not provide temperature measurement,
temperature compensation or salinity.

Part
Number
3400 Series Dip Cells
3401 1.0/cm 100/m Pyrex

3402 0.1/cm 10/m Pyrex

3403 1.0/cm 100/m Pyrex

3417 1.0/cm 100/m ABS

3418 0.1/cm 10/m ABS

3440 10.0/cm 1000/m Pyrex

3400 Series Flow-Through Cells
3445 1.0/cm 100/m Pyrex

3446 0.1/cm 10/m Pyrex

cgs Cell
Constant

SI Cell
Constant

These cells have the following specifications:

Material Overall

Length

191 mm 25 mm 21 mm 76 mm

7740

159 mm 25 mm 21 mm 52 mm

7740

178 mm 13 mm 10 mm 51 mm

7740

146 mm 13 mm 10 mm 20 mm

Plastic

159 mm 13 mm 10 mm 30 mm

Plastic

203 mm 13 mm 2 mm 86 mm

7740

146 mm 19 mm 10 mm 76 mm

7740

146 mm 25 mm 21 mm 76 mm

7740

O.D. Chamber

I.D.

Chamber
Depth

The nominal volumes of the cells are 15 mL for the YSI 3445 and 30 mL for the YSI 3255 and 3446 and
5 mL for the YSI 3254.

34

9.2 Standard Calibrator Solutions

YSI manufactures NIST-traceable conductivity calibrator solutions for calibration purposes. The
following conductivity calibrator solutions are available from YSI.

Part Number Size
3161 1 quart 1,000
3163 1 quart 10,000
3165 1 quart 100,000
3167 8 pints 1,000
3168 8 pints 10,000
3169 8 pints 50,000

Conductivity at 25.00

µµµµ

mho/cm

µµµµ

mho/cm

µµµµ

mho/cm

µµµµ

mho/cm

µµµµ

mho/cm

µµµµ

mho/cm

°°°°

C Resistivity at 25.00

±±±±

0.50%

±±±±

0.25%

±±±±

0.25%

±±±±

1.0%

±±±±

1.0%

±±±±

1.0%

1,000
100
10
1,000
100
20

ΩΩΩΩ
ΩΩΩΩ
ΩΩΩΩ
ΩΩΩΩ
ΩΩΩΩ
ΩΩΩΩ

cm
cm
cm
cm
cm
cm

±±±±

0.50%

±±±±

0.25%

±±±±

0.25%

±±±±

1.0%

±±±±

1.0%

±±±±

1.0%

°°°°

C

35

10. Required Notice

This equipment generates and uses radio frequency energy and if not installed and used properly,
may cause interference to radio and television reception. There is no guarantee that interference
will not occur in a particular installation. If this equipment does cause interference to radio or
television reception, which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following measures:

Reorient the receiving antenna

•

Relocate the computer with respect to the receiver

•

Move the computer away from the receiver

•

Plug the computer into a different outlet so that the computer and receiver are on

•

different branch circuits.

If necessary, the user should consult the dealer or an experienced radio/television technician for
additional suggestions. The user may find the following booklet, prepared by the Federal
Communications Commission, helpful: "How to Identify and Resolve Radio-TV Interference
Problems." This booklet is available from the U.S. Government Printing Office, Washington, DC
20402, Stock No. 0004-000-00345-4.

36

11. Appendix A - Specifications

Modes

Conductivity

Salinity

Temperature

Conductivity
Temperature compensated conductivity
Salinity
Temperature

Range Accuracy Resolution Frequency

0 - 49.99 µS* ± 0.5% full scale 0.01 µS
0 - 499.9 µS ± 0.5% full scale 0.1 µS
0 - 4999 µS** ± 0.5% full scale 1 µS
0 - 49.99 mS***
0 - 499.9 mS****

Range Accuracy Resolution

0-80 ppt (NaCl)

Range Accuracy Resolution

-5 - 95°C

Temperature Compensation

± 0.5% full scale
± 0.5% full scale

±

2% or ±0.1 ppt

±

0.1°C +1LSD

Method Linear
Ref. temp., °C 15 - 25
Temp. Coefficient 0 - 4%/°C

70 Hz
70 Hz
240 Hz

0.01 mS 1562 Hz

0.1 mS 1562 Hz

0.1 ppt

0.1°C

Cell constant, cm

-1

Display

Cell connector

Power

Approvals

Environmental requirements

Size

Weight

* Requires a cell constant of K=0.01, K=0.1 or K=1.
** Requires a cell constant of K=0.1, K=1 or K=10.
*** Requires a cell constant of K=1 or K=10.
**** Requires a c ell constant of K=10.

0.01

0.08 - 0.12

0.8 - 1.2
8 - 12

LCD

7-pin Mini Din

AC, 115V, 220V

UL, CSA, CE

95% RH non-cond

9 x 9.5 x 4.4 inches 22.9 x 24.1 x 11.2 cm

2.6 pounds 1.1 kg

37

12. Appendix B - Temperature Correction Data For

Typical Solutions

A. Potassium Chloride** (KCl)

Concentration: 1 mole/liter Concentration: 1 x 10-1 mole/liter

C

°

0 65.10 1.67 0 7.13 1.78

5 73.89 1.70 5 8.22 1.80
10 82.97 1.72 10 9.34 1.83
15 92.33 1.75 15 10.48 1.85
20 101.97 1.77 20 11.65 1.88
25 111.90 1.80 25 12.86 1.90

C

°

0 0.773 1.81 0 0.080 1.84

5 0.892 1.84 5 0.092 1.88
10 1.015 1.87 10 0.105 1.92
15 1.143 1.90 15 0.119 1.96
20 1.275 1.93 20 0.133 1.99
25 1.412 1.96 25 0.147 2.02
30 1.553 1.99 30 0.162 2.05
35 1.697 2.02 35 0.178 2.07

37.5 1.771 2.03 37.5 0.186 2.08
40 1.845 2.05 40 0.194 2.09
45 1.997 2.07 45 0.210 2.11
50 2.151 2.09 50 0.226 2.13

mS/cm

Concentration: 1 x 10-2 mole/liter Concentration: 1 x 10-3 mole/liter

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

C

°

30 14.10 1.93
35 15.38 1.96

37.5 16.04 1.98
40 16.70 1.99
45 18.05 2.02
50 19.43 2.04

C

°

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

** Charts developed by interpolating data from

International Critical Tables

, Vol. 6, pp. 229-253, McGraw-Hill Book Co., NY.

38

B. Sodium Chloride

Saturated solutions at all temperatures Concentration: 0.5 mole/liter

C

°

0 134.50 1.86 0 25.90 1.78

5 155.55 1.91 5 29.64 1.82
10 177.90 1.95 10 33.61 1.86
15 201.40 1.99 15 37.79 1.90
20 225.92 2.02 20 42.14 1.93
25 251.30 2.05 25 46.65 1.96
30 277.40 2.08 30 51.28 1.99

Concentration: 1 x 10-1 mole/liter Concentration: 1 x 10-2 mole/liter

C

°

0 5.77 1.83 0 0.632 1.87

5 6.65 1.88 5 0.731 1.92
10 7.58 1.92 10 0.836 1.97
15 8.57 1.96 15 0.948 2.01
20 9.60 1.99 20 1.064 2.05
25 10.66 2.02 25 1.186 2.09
30 11.75 2.04 30 1.312 2.12
35 12.86 2.06 35 1.442 2.16

37.5 13.42 2.07 37.5 1.508 2.17
40 13.99 2.08 40 1.575 2.19
45 15.14 2.10 45 1.711 2.21
50 16.30 2.12 50 1.850 2.24

*

(NaCl)

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

C

°

35 56.01 2.01

37.5 58.40 2.02
40 60.81 2.02
45 65.65 2.04
50 70.50 2.05

C

°

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

Concentration: 1 x 10-3 mole/liter

C

°

0 0.066 1.88

5 0.076 1.93
10 0.087 1.98
15 0.099 2.02
20 0.111 2.07
25 0.124 2.11
30 0.137 2.15
35 0.151 2.19

37.5 0.158 2.20
40 0.165 2.22
45 0.180 2.25
50 0.195 2.29

* Charts developed by interpolating data from the
Cleveland.

mS/cm

%/°C (to 25°C)

CRC Handbook of Chemistry and Physics

, 42nd ed., p. 2606, The Chemical Rubber Company,

39

C. Lithium Chloride

C

°

0 39.85 1.82 0 5.07 1.87

5 46.01 1.85 5 5.98 1.85
10 52.42 1.89 10 6.87 1.85
15 59.07 1.92 15 7.75 1.85
20 65.97 1.95 20 8.62 1.85
25 73.10 1.98 25 9.50 1.86
30 80.47 2.02 30 10.40 1.88
35 88.08 2.05 35 11.31 1.91

37.5 91.97 2.07 37.5 11.78 1.92
40 95.92 2.08 40 12.26 1.94
45 103.99 2.11 45 13.26 1.98
50 112.30 2.15 50 14.30 2.02

Concentration: 1 x 10-2 mole/liter Concentration: 1 x 10-3 mole/liter

C

°

0 0.567 1.88 0 0.059 1.93

5 0.659 1.92 5 0.068 2.03
10 0.755 1.96 10 0.078 2.12
15 0.856 2.00 15 0.089 2.19
20 0.961 2.04 20 0.101 2.25
25 1.070 2.08 25 0.114 2.28
30 1.183 2.12 30 0.127 2.31
35 1.301 2.16 35 0.140 2.32

37.5 1.362 2.18 37.5 0.147 2.32
40 1.423 2.20 40 0.154 2.31
45 1.549 2.24 45 0.166 2.29
50 1.680 2.28 50 0.178 2.25

*

(LiCl)

Concentration: 1 mole/liter Concentration: 1 x 10-1 mole/liter

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

C

°

C

°

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

D. Potassium Nitrate** (KNO3)

Concentration: 1 x 10-1 mole/liter Concentration: 1 x 10-2 mole/liter

C

°

0 6.68 1.78 0 0.756 1.77

5 7.71 1.79 5 0.868 1.80
10 8.75 1.81 10 0.984 1.83
15 9.81 1.83 15 1.105 1.86
20 10.90 1.85 20 1.229 1.88
25 12.01 1.87 25 1.357 1.90
30 13.15 1.90 30 1.488 1.93
35 14.32 1.92 35 1.622 1.95

37.5 14.92 1.94 37.5 1.690 1.96
40 15.52 1.95 40 1.759 1.97
45 16.75 1.97 45 1.898 1.99
50 18.00 2.00 50 2.040 2.01

* Charts developed by interpolating data from the
Cleveland.
** Charts developed by interpolating data from

mS/cm

International Critical Tables

%/°C (to 25°C)

CRC Handbook of Chemistry and Physics

C

°

, Vol. 6, pp. 229-253, McGraw-Hill Book Co., NY.

mS/cm

, 42nd ed., p. 2606, The Chemical Rubber Company,

%/°C (to 25°C)

40

E. Ammonium Chloride

Concentration: 1 mole/liter Concentration: 1 x 10-1 mole/liter

C

°

0 64.10 1.60 0 6.96 1.82

5 74.36 1.53 5 7.98 1.88
10 83.77 1.45 10 9.09 1.93
15 92.35 1.37 15 10.27 1.97
20 100.10 1.29 20 11.50 2.00
25 107.00 1.21 25 12.78 2.03

C

°

0 0.764 1.84 0 0.078 1.88

5 0.889 1.86 5 0.092 1.90
10 1.015 1.88 10 0.105 1.91
15 1.144 1.91 15 0.119 1.93
20 1.277 1.94 20 0.133 1.95
25 1.414 1.97 25 0.148 1.98
30 1.557 2.02 30 0.162 2.01
35 1.706 2.06 35 0.178 2.04

37.5 1.782 2.08 37.5 0.186 2.06
40 1.860 2.10 40 0.194 2.07
45 2.020 2.14 45 0.210 2.11
50 2.186 2.18 50 0.227 2.15

mS/cm

Concentration: 1 x 10-2 mole/liter Concentration: 1 x 10-3 mole/liter

mS/cm

*

(NH4Cl)

%/°C (to 25°C)

%/°C (to 25°C)

C

°

30 14.09 2.06
35 15.43 2.07

37.5 16.10 2.08
40 16.78 2.08
45 18.12 2.09
50 19.45 2.09

C

°

mS/cm

mS/cm

%/°C (to 25°C)

%/°C (to 25°C)

* Charts developed by interpolating data from the
Cleveland.

CRC Handbook of Chemistry and Physics

, 42nd ed., p. 2606, The Chemical Rubber Company,

41

13. Appendix C - Conversion Factors

TO CONVERT FROM TO EQUATION

mhos Siemens Multiply by 1
mhos ohms 1/mho
ohms mhos 1/ohm
Feet Meters Multiply by 0.3048
Meters Feet Multiply by 3.2808399
Degrees Celsius Degrees Fahrenheit
Degrees Fahrenheit Degrees Celsius

Units of Measure

Measurement Units Symbols

Resistance Ohm
Conductance Siemens S Mho
Conductance 1 / Resistance
Conductivity Siemens / Meter S / m or Mho / Centimeter
Cell Constant 1 / cm or 1 / m

ΩΩΩΩ

1 /

ΩΩΩΩ

9/5×(
5/9×(

o

C)+32

o

F-32)

Calculate conductivity by multiplying the measured conductance in mhos or siemens by the
appropriate cell constant (K), observing the dimensions of the constant.

42

14. Appendix D - Glossary of Terms

ampere
amplitude

cycle.

ASTM
calibrate

measurements.

calibrator solution
capacitance

property of being able to collect a charge of electricity. C = Q/V.

capacitor
cell constant

current flow. K=d/A.

cgs

SI units.

conductance

ends; the ability of a conductor to transmit current; the reciprocal of resistance. The SI unit is
siemens (S), also measured in mhos.

(A) - SI unit of electric current; one coulomb per second.

- The maximum deviation of an alternating current from its average value during its

- American Society for Testing and Materials

- To determine, check, or rectify the graduation of any instrument giving quantitative

- A solution of known value used to calibrate.

(C) - The ratio of the total charge on an isolated conductor to its potential; the

- An electrical component able to accumulate and hold an electric charge.
(K) - The ratio of the distance between two electrodes to the area normal to the

- Abbreviation for the centimeter-gram-second system of metric units. Mostly superseded by

(k) - The ratio of the current in a conductor to the potential difference between its

conductivity

current to flow; the inverse of resistivity; the conductance between opposite faces of a cube of the
measured material of 1 cm (cgs units) or 1 m (SI units) edge. Measured in mho/cm (cgs units) or
S/m (SI units)

conductivity cell
coulomb -

current of one ampere.

current
electrode

- Any atom or molecule that has an electric charge due to the loss or gain of valence

ion

electrons.

- Abbreviation for the meter-kilogram-second system of metric units.

mks

- A unit of conductance; the reciprocal of an ohm.

mho

(µ) - The metric prefix indicating 10-6.

micro

(m) - The metric prefix indicating 10-3.

milli

(ℵ) - The ratio of the current density in a conductor to the electric field causing the

- Any cell with electrodes used to measure the conductivity of liquid.

The quantity of electric charge which flowing by any point in one second produces a

(I) - The rate of flow of an electric charge, usually expressed in amperes.

- A conductor whereby an electric current enters or leaves a liquid, gas, or vacuum.

43

- National Institute of Standards and Technology. The US government agency that defines

NIST

measurement standards in the United States.

(Ω) - SI unit of resistance

ohm
OIML

- Organisation Internationale de Métrologie Légale is a treaty organization for the

harmonization of practical applications of measurement standards.

platinum black

- Platinum precipitated from a solution of the (IV) chloride by reducing agents.

A velvety-black powder.

polarization

- The separation of the positive and negative charges of a molecule by an external

agent.

- A trademark name for heat-resistant and chemical-resistant glass.

Pyrex
reference voltage
replatinize
resistance

- To deposit a new layer of platinum black on an electrode.

(R) - Opposition to the passage of current that causes electrical energy to be

- A closely controlled d.c. or a.c. voltage used as a reference.

transformed into heat.

resistivity

- An intrinsic property of a conductor, which gives the resistance in terms of its
dimensions; the resistance between opposite faces of a one-centimeter cube of a given material;
the inverse of conductivity.

- Système International is the international system of units.

SI
siemens
temperature correction

(S) - SI unit of electrical conductance; the reciprocal of an ohm; equivalent to a mho.

- An adjustment made to a measurement to compensate for the

difference between the measured and nominal temperatures.

temperature coefficient

temperature.

voltage

- Electromotive force or potential expressed in volts.

- The change in any particular physical quantity per degree change in

44

45

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