OHAUS starter 3100 User manual

STARTER 3100
Bench pH Meter
Instruction Manual

Table of Contents
1Introduction..........................................................................1
1.1 Safety measures.............................................................................. 1
1.2 Display and controls....................................................................... 2
2Installation............................................................................4
2.1 Package contents............................................................................ 4
2.2 Installing the stand-alone electrode holder.................................. 5
2.3 Installing the power adapter .......................................................... 5
2.4 Connect the pH electrodes............................................................. 6
2.5 Meter stand for adjusting view angle............................................ 6
2.6 Attached quick guide...................................................................... 6
3STARTER 3100 operation....................................................7
3.1 Calibration........................................................................................ 7
3.1.1 Buffer group................................................................................... 7
3.1.2 Performing 1-point calibration ....................................................... 8
3.1.3 Performing 2-point calibration ....................................................... 8
3.2 Sample measurement..................................................................... 9
3.2.1 pH measurement........................................................................... 9
3.2.2 mV measurement.......................................................................... 9
3.3 Temperature measurement ............................................................ 9
3.4 Using the memory......................................................................... 10
3.4.1 Storing a reading......................................................................... 10
3.4.2 Recalling from memory ............................................................... 10
3.4.3 Clearing the memory................................................................... 10
3.5 Printing............................................................................................11
4Setup...................................................................................12
4.1 Set temperature unit ..................................................................... 12
4.2 Set manual temperature compensation...................................... 12
4.3 Selecting a predefined buffer group ........................................... 12
5Maintenance.......................................................................13
5.1 Error message ............................................................................... 13
5.2 Meter maintenance........................................................................ 13
5.3 Electrode maintenance................................................................. 13
5.4 Self-diagnosis................................................................................ 14
5.5 Recover factory settings .............................................................. 14
6Specifications ....................................................................15
7Buffer group.......................................................................16

1
1 Introduction
Thank you for choosing OHAUS product.
Please read the manual completely before using the STARTER 3100 bench pH meter to avoid
incorrect operation.
STARTER 3100 has an excellent performance/price ratio and is designed with many useful features
including a stand-alone electrode holder, a beeper for error alert. Other accessories such as many
pH electrodes for different applications, and buffer solutions are also available.
You will find much helpful functionality in these meters. A few of the many existing features are:
Large backlight LCD with Quick Guide attached help user operate easily
Auto/manual endpoint which could help users freeze the stable reading value
3 buffer groups (US, EU and JJG) meet different requirements
RS232 can connect printer to print，99 data memory with last calibration data
1.1 Safety measures
Measures for your protection
Never work in an environment subject to explosion hazards! The housing of
the instrument is not gas tight. (explosion hazard due to spark formation,
corrosion caused by the ingress of gases)
When using chemicals and solvents, comply with the instructions of the
producer and the general lab safety rules.
Measures for operational safety
Do not unscrew the two halves of the housing
Dry off any liquid spills immediately! The instrument is not watertight
Exclude the following environmental influences:
oPowerful vibrations
oDirect sunlight
oAtmospheric humidity greater than 80%
oCorrosive gases present
oTemperatures below 5 °C and above 40 °C
oPowerful electric or magnetic fields

2
1.2 Display and controls
Displays
1
Electrode condition
Slope: more than 95%
and offset: ±(0-15) mV
Electrode condition is good
Slope: 90-95%
or offset: ±(15-35) mV
Electrode condition is
acceptable
Slope: less than 90%
or offset: ±(35-60) mV
Electrode condition is not
good or needs cleaning
2
Endpoint stability icon ; Auto endpoint icon
3
Measurement icon - ; measurement or calibration is running
4
Calibration icon - ; calibration in progress
5
Setup icon - ; instrument is in the setup mode, can set temperature(MTC), buffer group
etc.
6
pH/mV reading or slope in calibration process
7
Calibration point / Buffer group /Memory number / Error index
8
Auto temperature compensation - ATC ; Manual temperature compensation - MTC
9
Temperature during measurement or offset (mV) in calibration process
2
3
4
1
5
6
7
8
9

3
Controls
Button
Press & release
Press & hold
for 3 seconds
- Start or finish measurement
- Confirm setting, store entered
value
- Turn auto endpoint on / off
,
- Start calibration
- Recall the latest calibration
data : slope and offset
- Meter turn on
- Exit and return to measurement
screen
- Meter turn off
- Store current reading to memory
- Increase value during setting
- Scroll up through the memory
- Recall stored data
- Print current memory data
- Switch between pH and mV
- Decrease value during setting
- Scroll down through the memory
- Enter setup mode
- Start self-diagnosis
Turn on/turn off the backlight
of the LCD

4
2 Installation
Carefully unpack the box.
2.1 Package contents
The model ST3100-B (basic package) has the following items:
In addition to ST3100-B content, the ST3100-F package also includes the following:
Each pH buffer powder should be dissolved in 250ml pure water or deionized water in volumetric
flask. You also can order the bottle buffer solution from Ohaus.
Accessories:
Model
Description
Item NO
ST310
3-in-1 plastic refillable pH Electrode
83033965
ST210
2-in-1 plastic refillable pH Electrode
83033966
ST320
3-in-1 plastic gel pH Electrode(no need to fill)
83033967
ST230
2-in 1 glass muddy sample pH Electrode
83033968
STPURE
2-in-1 glass pure water sample pH Electrode
83033969
STTEMP30
Temperature Electrode
83033970
STORP1
Gel plastic ORP electrode
30038555
STORP2
Refillable glass ORP electrode
30038553
STREF01
Ag/AgCl reference electrode
30059253
Buffer powder set (4.01; 7.00; 10.0)
83033971
Buffer pH4.01 250ml
30065083
Buffer pH7.00 250ml
30065084
Buffer pH9.21 250ml
30065085
Buffer pH10.00 250ml
30065086
pH electrode Reference Electrolyte
30059255
pH electrode protection solution
30059256
pH sensor protect bottle(10 in bag)
30064800
Electrode holder stand alone (3100/3100C)
30058733
SF40A printer
30045641
In use cover
30058734
ST3100-B
Units
STARTER 3100
1
Stand-alone electrode holder
1 set
12V Power supply
1 set
pH Buffer Powder Set (4.01, 7.00, 10.01)
1 set
ST310 3-in-1 refillable pH electrode
1
In use cover
1

5
2.2 Installing the stand-alone electrode holder
Install the electrode arm on the base,
After adjust the tension knob to some extent, you can move up and down the upper arm
directly. When we put pH electrode on the arm and do calibration or measurement, we can
put the storage bottle of pH electrode into the base hole.
2.3 Installing the power adapter
Insert the right adapter clip into the power adapter slot. Ohaus balance power supply is also 12V
which could also be used for the pH meter.

6
2.4 Connect the pH electrodes
There are 3 sockets for electrode. “pH”socket (BNC); “TEMP.”Socket (Cinch) and “REF”Socket
(2mm banana).
For ST310 electrode, should connect the BNC and Cinch socket. For 2-in-1 pH electrode (ST210)
only need to connect the BNC.
REF socket is for separate reference electrode. (e.g.STREF01)
2.5 Meter stand for adjusting view angle
One unique design of the STARTER 3100 is the meter stand, which can be used to adjust the view
angle of the display in case of working on high table.
2.6 Attached quick guide
Another unique design of the STARTER 3100 is the attached quick guide, the quick guide is
attached into the bottom housing of the meter, you can use finger to pull it out.

7
3 STARTER 3100 operation
The procedure of pH measurement is the following; the key points are the pH electrode, rinse,
calibration, storage.
a) pH electrode preparation
b) buffer preparation and pH electrode calibration
c) sample preparation
d) pH measurement
e) Measurement result record or print
f) Rinse the pH electrode and storage
pH electrode preparation: pH electrode should be rinsed with pure water before and after using.
Check if the electrode is physically damaged. (Be careful with the glass bulb)
The pH electrode should be stored in the storage bottle; the solution in the bottle is 3M KCl
solution. After the pH electrode put into the sample or buffer solution, user should stir several
seconds then wait 30 to 60 seconds for the signal to be stable, and then press the button to
operate (Calibration or measurement).
3.1 Calibration
3.1.1 Buffer group
STARTER 3100 can perform 1-, 2- or 3- point calibrations.
There are 3 buffer groups in the meter, you can select the buffer group you prefer (see 4.3),
default buffer is b1 US standards; the buffer value will be automatically recognized during
calibration. The 3 predefined buffer groups are (at 25°C):
STARTER 3100 automatically corrects for the temperature dependence of the buffer pH values
given in the following table - buffer group b1.
b1
1.68
4.01
7.00
10.01
b2
2.00
4.01
7.00
9.21
11.00
b3
1.68
4.00
6.86
9.18
12.46
5°C
1.67
4.01
7.09
10.25
10 °C
1.67
4.00
7.06
10.18
15 °C
1.67
4.00
7.04
10.12
20 °C
1.68
4.00
7.02
10.06
25 °C
1.68
4.01
7.00
10.01
30 °C
1.68
4.01
6.99
9.97
35 °C
1.69
4.02
6.98
9.93
40 °C
1.69
4.03
6.97
9.89
45 °C
1.70
4.05
6.97
9.86
50 °C
1.71
4.06
6.96
9.83

8
3.1.2 Performing 1-point calibration
Calibration: pH electrode need to be calibrated with pH standard buffer solution before a proper
pH measurement. Calibration is to display the right pH value when meter receive the mV value
signal from the pH electrode.
Slope: the linear coefficient between mV and pH according to theoretical value (e.g. -
59.16mV/pH @ 25°C which means 100% slope);
Offset: the mV value when pH value is 7.00. (Theoretical value is 0 mV);
When STARTER 3100 is in pH measurement mode (see 3.2); place the pH electrode in a
calibration buffer, then:
Press button-Cal, “Cal 1”displays on the bottom left of the screen and “Cal ”is blinking.
and appear on the top of the screen, is blinking during calibration.
The meter reaches endpoint according to the endpoint mode, the calibration point pH value
(e.g. 7.00) with the temperature display on the screen.
The 1-point calibration is finished; now we have 3 choices to do next:
Press button-Cal to do the 2-point calibration.
Press button-Read to store the 1-point calibration and exit, the offset and the slope are
shown on the display for 3 seconds then return to the measurement screen.
Press button-Exit to reject the calibration, return to the measurement screen.
Endpoint Mode: We have two endpoint modes - auto endpoint and manual endpoint. By
pressing and holding button-Read, you can switch between the 2 endpoint modes.
oTo manually endpoint a measurement or calibration, you need to press button-
Read: the sample reading freezes, the endpoint stability icon blinks 3 times
and freezes on the display.
oWhen in auto endpoint mode, the meter judges if the reading is stable then
endpoint automatically, the reading freezes and blinks 3 times then disappears;
auto endpoint icons blink 3 times and freeze on the display.
oStability criterion: the signal of the sensor input may not change by more than
0.1mV in 6 seconds.
Note: With the 1-point calibration only the offset is adjusted. If the sensor was previously
calibrated with multi-point calibration the previously stored slope will remain. Otherwise theoretical
100% slope (-59.16 mV / pH) will be used.
3.1.3 Performing 2-point calibration
Perform 1-point calibration as described above.
Rinse the pH electrode with pure water and wipe off with tissue.
Place the electrode in the next calibration buffer and press button-Cal,“Cal 2”displays on the
bottom left of the screen and “Cal ”is blinking. on the top of the screen and appear,
is blinking during calibration.

9
The meter reaches endpoint according to the endpoint mode, the calibration point pH value
(e.g. 4.01) with the temperature display on the screen.
The 2-point calibration is finished, now we have 3 choices to do next:
Press button-Cal to do the 3-point calibration.
Press button-Read to store the 2-point calibration and exit, the offset and slope are shown
on the display for 3 seconds then return to the measurement screen.
Press button-Exit to reject the calibration, return to the measurement screen.
Note: The use of a temperature electrode or an electrode with a built-in temperature sensor (3-in-
1 pH electrode) is recommended. If you use the MTC mode, you should enter the correct
temperature value and keep all buffer and sample solutions at the set temperature. (See 4.2)
3.2 Sample measurement
3.2.1 pH measurement
Place the pH electrode in the sample.
Press button-Read to start the pH measurement, appears on the display. is blinking
during measurement.
When meter reaches endpoint, the pH value with the temperature display on the screen.
3.2.2 mV measurement
Press button-Mode to switch between pH measurement mode and mV measurement
mode.
Follow the same procedure as for pH measurement to perform mV measurement.
3.3 Temperature measurement
For better accuracy, we recommend to use either a built-in or a separate temperature electrode.
If a temperature electrode is used, ATC and the sample temperature are displayed.
If the meter does not detect a temperature electrode, it automatically switches to the manual
temperature compensation mode and MTC appears. MTC temperature should be set.
Note: STARTER 3100 accepts NTC 30 kΩ temperature sensor. ATC (Auto Temperature
Compensation) or MTC (Manual Temperature Compensation) , the Temperature Compensation
only corrects for the change in the output of the electrode, not for the change in the actual solution.
That means the meter corrects the signal(mV) from the pH electrodes to get a more accuracy pH
value according to the real temperature.

10
3.4 Using the memory
3.4.1 Storing a reading
The STARTER 3100 can store up to 30 endpoint results.
Press button-Store when the measurement reaches endpoint. M01 indicates that one result
has been stored.
If you press button-Store when M99 is displayed, FUL displays to indicate the memory is full. To
store further data you will have to clear the memory. (See 3.4.3)
3.4.2 Recalling from memory
Press and hold button-Recall to recall the stored values from memory when the current
measurement reaches endpoint.
Press button-up or button-down to scroll through the stored results. R01 to R99 indicates
which result is being displayed.
Press button-Exit to exit.
3.4.3 Clearing the memory
Pressing button-up or button-down to scroll through the stored results until “MRCL”appears.
Press button-Read, CLr blinks;
Now we can two choices:
Press button-Read to confirm the deletion of all the stored data.
Press button-Exit to return to the measurement mode without deleting the memory.

11
3.5 Printing
If the printer is connected to the STARTER 3100(e.g. SF-F40A, green light means connection
success), a print-out is automatically generated after each end pointed measurement or
calibration.
The format for the print-out following a pH measurement is:
End Point, Value, Temp., ATC/MTC
Auto EP, 4.01pH, 25.0ºC , MTC
The details for the second line are:
Auto EP, 4.01pH, 25.0ºC , MTC
| | | |---- Manual Temperature Compensation
| | |---------------- Temperature value and unit ºC
| |------------------------- pH value
|---------------------------------------- Auto End Point
The format for the print-out following a mV measurement is:
End Point, Value, Temp., ATC/MTC
Manual EP, 182mV, 23.2ºC , ATC
The print-out in case of an error message is:
End Point, Value, Temp., ATC/MTC
Error3
The print-out for a 2-point calibration is:
Buffer1: 4.01pH
mV1: 178mV
Temp.1: 25.0ºC
Buffer2: 7.00pH
mV2: 3mV
Temp.2: 25.0ºC
Slope: 99%
Offset: 5mV
ATC/MTC: MTC
The print-out for a 3-point calibration is:
Buffer1: 4.01pH
mV1: 178mV
Temp.1: 25.0ºC
Buffer2: 7.00pH
mV2: 0mV
Temp.2: 25.0ºC
Buffer3: 9.21pH
mV3: -130mV
Temp.3: 25.0ºC
Slope: 100%
Offset: 0mV
ATC/MTC: ATC
Printing from memory When scrolling through the memory you can print the entry that is currently
viewed by pressing and holding(3 seconds) the button-Store. The printout format is followings:
Recall 01:
End Point, Value, Temp., ATC/MTC
Manual EP, 4.01pH, 35.6ºC , ATC

12
4 Setup
4.1 Set temperature unit
To set the temperature, you need go into the setup screen. When
Press and hold button-Mode/Setup until the setup icon appears on the display and the
current temperature unit blinks.
Press button-up or button-down to switch between ºC and ºF .
Press button-Read to confirm your selection.
Then
Continue with MTC temperature setting or
Press button-Exit to return to the measurement screen.
4.2 Set manual temperature compensation
After confirming the temperature unit, the MTC (Manual Temperature Compensation)
temperature value appears on the display. Then use button-up or button-down to increase or
decrease the value to the temperature of your sample. Press button-Read to confirm the setting or
press button-Exit to return to the measurement screen.
The default MTC temperature value setting is 25 °C (77 ºF).
Note: ºC = 5/9 (ºF -32)
4.3 Selecting a predefined buffer group
After confirming the MTC compensation temperature value, it goes to the buffer group selection.
Use button-up or button-down to select a buffer group among 4 buffer groups (3.1.1). Press
button-Read to confirm the setting or press button-Exit to leave to return to the measurement
screen.
The default buffer group is b1.
b1
1.68
4.01
7.00
10.01

13
5 Maintenance
5.1 Error message
Error 0
Memory access error
Reset to factory settings
Error 1
Self-diagnosis failed
Repeat the self-diagnosis procedure and make
sure that you finish pressing all five keys within
two minutes.
Error 2
Measured values out of range
Check if the electrode is properly connected and
placed in the sample solution.
Error 3
Measured buffer temperature
out of range (<5 or >40 °C)
Keep the pH buffer temperature within the range
for calibration
Error 4
Offset out of range
offset > 60mV or < - 60 mV
Make sure the pH buffer is correct and fresh;
Clean or replace the pH electrode.
Error 5
Slope out of range
Make sure the buffer is correct and fresh; Clean
or replace the pH electrode.
Error 6
Meter cannot recognize the
buffer
Make sure the buffer is correct and fresh; check if
the buffer has not been used more than once.
Error 9
The current data set has
already been stored once
An endpoint reading can only be stored once.
Perform a new measurement to store.
Error 10
The sample temperature out
of range
Check the sample temperature, the temperature
sensor.
If error happens, the meter will also beep 3 times to alert.
Any more problems, you can contact Ohaus sales rep or email [email protected].
5.2 Meter maintenance
Never unscrew the two halves of the housing!
The STARTER 3100 series instruments do not require any maintenance other than occasional wipe
with a damp cloth and the replacement of depleted batteries.
The housing is made of acrylonitrile butadiene styrene (ABS). This material is attacked by some
organic solvents, such as toluene, xylene and methyl ethyl ketone (MEK). Any spillage should be
immediately wiped off.
5.3 Electrode maintenance
Make sure the electrode is filled with electrolyte solution. Always store the electrode according to
the electrode instruction manuals and do not allow it to dry out.
If the electrode response becomes sluggish or the slope is not good enough, try:
oSoak the electrode in 0.1M HCl for more than 8 hours.
oFor fat or oil contaminant, degrease the membrane with cotton wool soaked in either

14
acetone or a soap solution.
After electrode treatment, a new calibration should be performed. If the electrode slope is still not
good, the electrode might need to be replaced.
5.4 Self-diagnosis
When meter is on, press and hold button-Read and button-Cal simultaneously until the meter
displays the full screen. Each icon blinks one after the other.
This way you may check whether all icons are correctly shown. The next step is to check that the
keys are functioning correctly. This requires user interaction.
When bblinks, five icons are displayed.
Press the five keys in any order. Each time you press a key an icon disappears from the
screen, continue to press the other keys until all the icons have disappeared.
When the self-diagnosis has been completed successfully, PAS appears. If self-diagnosis fails,
error message Err 1 appears.
Note: You have to finish pressing all five keys within 2 minutes, otherwise Err 1 appears and you
will have to repeat the procedure.
5.5 Recover factory settings
When the meter is off, press and hold button-Read & button-Cal & button-Exit together for 3
seconds, the screen displays and blinks, means “Reset”. Then we have 2 choice:
Press button-Read to reset factory settings (MTC, slope and offset, etc.), display
then restart the meter.
Or press button-Exit to quit the setting, display then turn off the meter.

15
6 Specifications
STARTER 3100
Measuring range
-2.00…16.00 pH
–1999…1999 mV
-5 °C…110 °C
Resolution
0.01 pH
1 mV
0.1 °C
Error limits
±0.01 pH
±1 mV
±0.5 °C
Calibration
3 points
3 predefined buffer group
Memory
99 measurements
The last calibration data
Power supply
110-240V/50Hz, DC 12V
Size/weight
Approximately 220 W x 175 D x 78 H mm / 0.75 kg
Display
Liquid crystal with backlight
Input
BNC, impedance > 10e+12 Ω
Cinch, NTC 30 kΩ
Reference input
2mm banana socket
Temperature-compensation
ATC & MTC
Housing
ABS

16
7 Buffer group
STARTER 3100 automatically correct for the temperature dependence of the buffer group pH value
given in the following tables (b2, b3), you can find b1. (see 3.1.1)
Buffer group b2 Europe standard
Temp℃pH2.00 pH4.01 pH7.00 pH9.21 pH11.00
5 2.02 4.01 7.09 9.45 11.72
10 2.01 4.00 7.06 9.38 11.54
15 2.00 4.00 7.04 9.32 11.36
20 2.00 4.00 7.02 9.26 11.18
25 2.00 4.01 7.00 9.21 11.00
30 1.99 4.01 6.99 9.16 10.82
35 1.99 4.02 6.98 9.11 10.64
40 1.98 4.03 6.97 9.06 10.46
45 1.98 4.04 6.97 9.03 10.28
50 1.98 4.06 6.97 8.99 10.10
Buffer group b3 JJG119
Temp℃pH1.68 pH4.00 pH6.86 pH9.18 pH12.46
5 1.67 4.00 6.95 9.39 13.21
10 1.67 4.00 6.92 9.33 13.01
15 1.67 4.00 6.90 9.28 12.82
20 1.68 4.00 6.88 9.23 12.64
25 1.68 4.00 6.86 9.18 12.46
30 1.68 4.01 6.85 9.14 12.29
35 1.69 4.02 6.84 9.11 12.13
40 1.69 4.03 6.84 9.07 11.98
45 1.70 4.04 6.83 9.04 11.83
50 1.71 4.06 6.83 9.02 11.70