YSI 3100 User Manual

CONDUCTIVITY INSTRUMENT

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

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

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

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.

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

1.2 Controls

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

22.4

°C

Displa

ENTER Ke

UP ARROW

DOWN ARROW

The following diagram shows the typical display.

Conductivity:

mS/cm

uS/cm

Temperature compensated conductivity:

mS/cm

uS/cm

Salinity:

ppt

10.00

24.8

°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.

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

•

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

°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

when using a 3400 series cell,

Conductivity

16.34

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

CAL

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

°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.

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

flashing on and off.

If the instrument is reading either a

µµµµ

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

°C

Salinity with °C

the large numbers on the

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.

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

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.

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.

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

°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

°C

Calibration solution value

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