YSI 3100 User manual

YSI Model 3100
Conductivity
Salinity
Temperature
Instrument
Operations
Manual
C
µS
CONDUCTIVITY INSTRUMENT

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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

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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

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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 oC), along with one of the following
parameters: conductivity (in µS/cm or mS/cm), temperature compensated conductivity, (in
µS/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] key.
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.
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

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1.2 Controls
Front Panel
The front panel of the instrument contains the display and keypad as shown below.
3100 CONDUCTIVITY INSTRUMENT
12.85uS
22.4°C
Power
ON/OFF
MODE Key
Dis
p
la
y
ENTER Ke
y
UP ARROW
DOWN ARROW

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The following diagram shows the typical display.
10.00µS
24.8°C
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.
@ 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.
Conductivity:
mS/cm
uS/cm
Temperature compensated conductivity:
mS/cm
uS/cm
Salinity:
ppt
Temperature: °C
Adapter mounting post
NOTE: Flashing °C symbol
indicates temperature
compensation is enabled.

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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, when using a 3400 series cell, temperature measurement,
temperature compensation or salinity measurement is not possible.
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 937-
767-7241, 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

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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 6 Troubleshooting. After the instrument completes this
diagnostic routine, the following screen should be displayed (with no cell connected).
0.00µS
udr°C
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, when using a 3400 series cell,
temperature measurement, temperature compensation or salinity measurement is not
possible.
Cell constant

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16.34µS
24.8 °C
3.3 Configure the 3100
Before operating the 3100, or whenever you change cells, you must configure the 3100 to match
the cell used. You must enter the manufacturer’s stated (or your manually calculated) cell
constant (K) as shown below (Cell Constant).
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).
Cell Constant
Follow these steps to change the cell constant.
1. With the instrument on, press and release the [DOWN ARROW] and [MODE] keys at the
same time. The CAL symbol will appear at the bottom left of the display and the large portion
of the display will show 1.91%(or a value set previously using Advanced Setup).
1.91%
22.7 °C
CAL
2. Press and release the [MODE] key. The large portion of the display will show 25.0C (or a
value set previously using Advanced Setup).
3. Press and release the [MODE] key again. The large portion of the display will show 1.00 (or a
value set previously using Advanced Setup).
Temperature: °C
Conductivity
Cal symbol