Thermo Scientific Orion ROSS Ultra User manual

ROSS Ultra, ROSS Ultra Triode
and ROSS pH Electrodes
263745-001 •Revision B •November 2014
Thermo Scientic Orion
User Manual

Contents
Introduction 4
ROSS Electrode Families 4
ROSS Ultra Electrodes 4
ROSS Ultra pH/ATC Triode Electrodes 4
ROSS Electrodes 5
ROSS Sure-Flow Electrodes 5
ROSS Semi-micro Electrodes 5
ROSS micro pH Electrodes 5
Required Equipment 5
Electrode Preparation 6
Preparation for Refillable ROSS Electrodes 6
Preparation for ROSS Sure-Flow Electrodes 7
Preparation for Gel-Filled ROSS Ultra Triode Electrodes 8
Sample Requirements 8
Measuring Hints 9
Electrode Calibration 10
General Calibration Procedure 10
One Buffer Calibration 10
Two Buffer Calibration 11
pH Measurements 12
Electrode Storage 12
Electrode Maintenance 12
Electrode Cleaning Procedures 12
General Cleaning 12
Cleaning Solutions 13
Electrode Characteristics 13
Temperature Effects 13
Sure-Flow Electrode Leak Rate 14
ROSS Micro pH Electrode 14
ROSS Ultra pH/ATC Triode Electrodes 15
ROSS Electrode Operation with Orion Versa star pH/
LogR Meters 15
Electrode Interferences 16
Troubleshooting 17
pH Meter 17
Electrode 17
Sample/Application 17
Technique 17
Assistance 18
Warranty 18
RoHS Statement 18
Ordering Information 19
Specifications 21

4|ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Introduction
This user manual contains information on the preparation, operation
and maintenance of the Thermo Scientific™Orion™ROSS Ultra™,
Thermo Scientific™Orion™ ROSS™, and Thermo Scientific™Orion™
ROSS™Triode™electrodes.
All ROSS pH electrodes have a pH range of 0 to 14, pH precision of
0.01 and temperature range of 0 to 100°C. ROSS electrodes can be
used in samples that contain TRIS, sulfides and proteins since they do
not contain silver or mercury.
ROSS electrodes incorporate the distinctive ROSS internal reference
system that provides superior measurement stability, faster response,
greater accuracy and more reproducible results than conventional
electrodes. ROSS electrodes have a double junction reference, so
the fill solution can be modified to more closely match the sample
composition in high pH, low pH or non-aqueous solutions.
ROSS electrodes provide readings stable to 0.01 pH in less
than 30 seconds, even in the extreme case of samples varying from
one another by 50°C or more. Results are three to five times more
precise than those obtained with conventional electrodes. Over the
lifetime of the electrode, ROSS reference potential drifts less than an
average 0.12mV per day, which corresponds to 0.002 pH units, so
recalibration is minimized.
• The majority of ROSS electrodes with a BNC waterproof or BNC
connector have a one meter (three foot) long cable, except where
noted.
• All electrodes with a screw cap connection require a separate cable.
• Electrodes with a waterproof BNC connector can be used on any pH
meter with a BNC connection.
• The 800500U ROSS Ultra reference half-cell and 800300 ROSS
reference half-cell can be used with the 8101BNWP and 8101SC
ROSS pH half-cell electrodes or 8411BN ROSS sodium half-cell
electrode.
ROSS Electrode Families
ROSS Ultra Electrodes
ROSS Ultra electrodes offer the ultimate measurement stability and the
least long-term drift, plus a two year warranty for refillable models and
an 18 month warranty for gel-filled models.
ROSS Ultra pH/ATC Triode Electrodes
ROSS Ultra pH/ATC Triodes have a built-in temperature probe,
so pH and temperature are measured with one electrode.
Gel-filled ROSS Ultra pH/ATC Triode electrodes have an 18 month
warranty and refillable ROSS Ultra pH/ATC Triode electrodes have a 24
month warranty.

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |5 Thermo Scientic Orion
ROSS Electrodes
ROSS electrodes provide precise pH measurements and measurement
stability regardless of temperature changes or sample composition.
ROSS Sure-Flow Electrodes
ROSS Sure-Flow electrodes incorporate a free-flowing junction that is
easy to clean and never clogs. These electrodes are ideal for dirty or
viscous samples that clog traditional electrodes.
ROSS Semi-micro Electrodes
ROSS semi-micro electrodes are designed for applications where
sample volume is limited and can take measurements in samples of 0.2
ml volume. They are available with chemically-resistant glass (6 mm
tip) or epoxy (8 mm tip) bodies, Sure-Flow junction and ROSS Ultra
long-life models.
ROSS micro pH Electrodes
ROSS micro pH electrodes have been designed to measure
extremely small samples. The measuring tip is 3 mm in diameter and
40 mm long. The minimum depth of immersion is 4.5 mm and the
minimum sample size is 15 μL in 384 well plates.
Required Equipment
1. Thermo Scientific™Orion™Versa star™, Thermo Scientific™Orion
Star™A300 series, Thermo Scientific™Orion Star™A200 series,
Thermo Scientific™Orion Star™A100 series or Thermo Scientific™
Orion™ Dual star™meter with pH measurement capability,
such as the Versa star benchtop meter with pH module, Star
A211 pH benchtop meter or Star A321 pH portable meter;
except 8107BNURCA, 8157BNURCA and 8302BNURCA Triode
electrodes which are designed for use with a meters which support
a thermister with a 30K NTC curve and have an RCA plug, such as
the Five and Seven Series METTLER TOLEDO™pH meters.
ROSS electrodes can be used on any pH meter with a BNC
connection. The electrodes can also be used on meters with
a variety of inputs when an adapter cable is used. Visit www.
thermoscientific.com/water for details.
2. Orion ROSS Ultra, and ROSS Triode electrodes.
• The 8302BNUMD, 8107BNUMD, 8107UWMMD, 8157BNUMD
and 8157UWMMD pH/ATC Triode electrodes have a
temperature connector that is compatible with Orion Star A
series, Versa star and Dual star pH meters.
• The 8107BNURCA, 8157BNURCA and 8302BNURCA pH/
ATC Triode electrodes have a temperature connector that is
compatible with meters which support a thermister with a 30K
NTC curve and have an RCA plug, such as the Five and Seven
Series METTLER TOLEDO pH meters.
3. ROSS fill solution, Cat. No. 810007.
Note: Do not use any fill solution that contains silver, as silver
will damage ROSS electrodes.

6|ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Note: The 8107BNUMD, 8107UWMMD and 8107BNURCA
electrodes are gel-filled and do not require any fill solution.
4. ROSS pH electrode storage solution, Cat. No. 810001, or standard
pH electrode storage solution, Cat. No. 910001. For enhanced
electrode performance, use ROSS pH electrode storage solution.
5. pH buffers – at least two pH buffers are recommended for precise
measurements. One buffer should be near pH 7 and buffers should
be one to four pH units apart.
6. Beakers, plastic or glass.
7. Magnetic stirrer or Orion stirrer probe, Cat. No. 096019. The stirrer
probe can be used with Orion Star A series, Versa star and Dual
star benchtop meters.
8. Distilled or deionized water.
Electrode Preparation
Preparation for Refillable ROSS Electrodes
1. Remove the shipping cap, sleeve or bottle from the sensing bulb
and save it for later storage of the electrode.
2. Clean any salt deposits from the exterior of the electrode by rinsing
it with distilled water. Handle the 8220BNWP ROSS micro pH
electrode with great care.
3. The electrode may arrive with the chamber partially filled with
electrolyte solution. Please fill the chamber with electrolyte solution
before use. Uncover the fill hole by removing the tape and add
ROSS fill solution, Cat. No. 810007, to the electrode up to the fill
hole. To maintain an adequate flow rate, the level of fill solution
must always be above the reference junction and at least one inch
above the sample level. The fill hole should remain open whenever
the electrode is in use.
4. Place the electrode in an electrode holder and suspend the
electrode in air for 5 minutes to thoroughly wet the reference
junction. Omit this step for electrodes which come shipped in a
storage bottle.
5. Shake the electrode downward (similar to a clinical thermometer)
to remove any air bubbles. The 8220BNWP electrode is extremely
fragile. Do not shake the 8220BNWP electrode unless there are
air bubbles in the fill solution and then shake gently and with great
care.
6. Soak electrode in ROSS pH electrode storage solution,
Cat. No. 810001, or standard pH electrode storage solution, Cat.
No. 910001, for 30 to 60 minutes. ROSS Ultra Triode electrodes
do not need to be soaked prior to use, since they are shipped in a
storage bottle with storage solution.
7. Connect the electrode to the meter.

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |7 Thermo Scientic Orion
Fill hole
ROSS
internal
reference
Fill
solution
chamber
Reference
junction
pH sensing
bulb
Fill hole
ROSS
internal
reference
Fill solution
chamber
Sure-Flow
reference
junction
pH sensing
bulb
ROSS Refillable Combination pH Electrode
Preparation for ROSS Sure-Flow Electrodes
1. Remove the shipping cap, sleeve or bottle from the sensing bulb
and save it for later storage of the electrode.
2. Clean any salt deposits from the exterior of the electrode by rinsing
it with distilled water.
3. Uncover the fill hole by removing the tape and add ROSS fill
solution, Cat. No. 810007, to the electrode up to the fill hole. To
maintain an adequate flow rate, the level of fill solution must always
be above the reference junction and at least one inch above the
sample level. The fill hole should remain open whenever the
electrode is in use.
4. Wet the junction by pressing down on the electrode cap to let a few
drops of the ROSS fill solution flow out of the electrode and then
replenish any lost fill solution.
5. Shake the electrode downward (similar to a clinical thermometer) to
remove any air bubbles.
6. Soak electrode in ROSS pH electrode storage solution, Cat.
No. 810001, or standard pH electrode storage solution, Cat.
No. 910001, for 30 to 60 minutes. For enhanced electrode
performance, use ROSS pH electrode storage solution.
7. Connect the electrode to the meter.
Fill hole
ROSS
internal
reference
Fill
solution
chamber
Reference
junction
pH sensing
bulb
Fill hole
ROSS
internal
reference
Fill solution
chamber
Sure-Flow
reference
junction
pH sensing
bulb

8|ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
pH sensing bulb
Reference junction
ROSS
internal
reference
Gel solution
chamber
ROSS Gel-filled Combination pH
Electrode
Sample Requirements
A benefit of the ROSS pH electrodes is that the fill solution composition
may be changed depending on the sample requirements. The ROSS
pH electrode fill solution, Cat. No. 810007, is 3 M KCl. For solutions
that precipitate in the presence of chloride ions, the electrode can be
filled with 10% KNO3, Cat. No. 900003.
Electrodes with an epoxy body should only be used in aqueous
solutions.
Electrodes with a glass body may be used in non-aqueous solutions
and solutions that contain organic solvents. A minimum of 20% water
must be present in the sample for the best measurement results. If
there is a great deal of drift when using the ROSS electrode filled with
ROSS fill solution, try filling the electrode with a mixture of methanol
Preparation for Gel-Filled ROSS Ultra Triode
Electrodes
1. Remove the electrode storage bottle from the sensing bulb and
save it for later storage of the electrode.
Note: Unscrew the cap on the electrode storage bottle before
removing the electrode.
2. Clean any salt deposits from the exterior of the electrode by rinsing
it with distilled water.
3. Connect the electrode to the meter.
4. If the electrode will not be used immediately, soak it in ROSS
pH electrode storage solution, Cat. No. 810001, or standard pH
electrode storage solution, Cat. No. 910001.

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |9 Thermo Scientic Orion
and water saturated with KCl. The ratio of methanol to water should be
similar to the sample composition. For tips on measuring pH in non-
aqueous samples, see Thermo Scientific Water Analysis Instruments
Application Note 007.
If using the 8220BNWP ROSS micro pH electrode, great care must
be taken to thoroughly rinse out the reference chamber and junction
before changing the reference solutions.
Measuring Hints
• Always use fresh buffers for calibration. Choose buffers that are one
to four pH units apart.
• Check the electrode slope daily by performing a two buffer
calibration. The slope should be 92 to 102%.
• Except as noted in the Sample Requirements section, only use
ROSS fill solution, Cat. No. 810007. Do not use any fill solution that
may contain silver.
• If a refillable electrode is used, always remove the fill hole cover
during measurements to ensure a uniform flow of fill solution.
• If a ROSS Ultra Triode is used, immerse the electrode at least 2
inches (5 cm) in solution for best temperature response.
• Between measurements, rinse the electrode with distilled water and
then with the next solution to be measured.
• Stir all buffers and samples at a uniform rate.
• Place a piece of insulating material, such as polystyrene foam or
cardboard, between the magnetic stir plate and beaker to prevent
measurement errors from the transfer of heat to the sample. Since
ROSS electrodes respond quickly to temperature changes, pH
changes due to temperature variations will be noticed.
• To reduce the chance of error due to polarization, avoid rubbing or
wiping the sensing bulb. Use a lint-free tissue and gently blot the
sensing bulb.
• If a refillable electrode is used in dirty or viscous samples or
the electrode response becomes sluggish, empty the electrode
completely and hold the junction under running water. Empty any
water from the electrode and refill it with fresh ROSS fill solution.
For a thorough cleaning method, refer to the Electrode Cleaning
Procedures section.
• If a Sure-Flow electrode is used in dirty or viscous samples or
the electrode response becomes sluggish, empty the electrode
completely and hold the junction open under running water. Empty
any water from the electrode and refill it with fresh ROSS fill
solution. Press down on the electrode cap to let a few drops of the
ROSS fill solution flow out of the electrode and then replenish any
lost solution. For a thorough cleaning method, refer to the Electrode
Cleaning Procedures section.
• Handle the 8220BNWP ROSS micro pH electrode with care. Do
not touch the pH bulb and stem against the bottom or walls of the
sample containers.

10 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
• Flat surface ROSS pH electrodes may be used on any
moist surface or in liquids.
Using a Flat Surface Electrode
Electrode Calibration
General Calibration Procedure
For detailed instructions on pH calibration, manual pH calibration and
temperature compensation, consult your meter user guide. When
using ROSS electrodes with a Versa star pH/LogR meter, refer to the
Versa star pH/LogR meter user guide for instructions on temperature
calibration and LogR temperature compensated pH measurements.
Note: If the meter is set to automatically recognize the pH buffer at the
measured temperature and an ATC probe is used, you do not need to
manually adjust the pH values of the buffers.
One Buffer Calibration
1. Choose a buffer near expected sample pH.
2. The buffer should be at same temperature as the sample. If the
buffer and samples are at varying temperatures, temperature
compensation is recommended.
3. Prepare the meter according to the meter user guide.
4. Rinse the electrode first with distilled water and then with the buffer
being used for calibration.
Filling hole should
be uncovered
Fresh pH buffer
Stir all samples
and buffers
Filling solution level
must be higher than
sample level
Reference junction
must be immersed
Place insulation
between stirrer
and beaker
Measuring Hints

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |11 Thermo Scientic Orion
5. Place the electrode into the buffer. When the reading is stable,
set the meter to the pH value of the buffer at the measured
temperature. Refer to the meter user guide for a detailed
procedure. Table 1 provides pH buffer values at various
temperatures.
6. Proceed to the pH Measurement section.
Two Buffer Calibration
This procedure is recommended for precise measurements.
1. Select two buffers that bracket the expected sample pH. The first
buffer should be near the electrode isopotential point (pH 7) and
the second should be near the expected sample pH (pH 4 or pH
10). Buffers should be one to four pH units apart.
2. The buffers should be at same temperature as the sample. If the
buffers and samples are at varying temperatures, temperature
compensation is recommended.
3. Rinse the electrode first with distilled water and then with the first
buffer.
4. Place the electrode into the first buffer. When the reading is
stable, set the meter to the pH value of the buffer at the measured
temperature. Refer to the meter user guide for a detailed
procedure. Table 1 provides pH values at various temperatures.
5. Rinse the electrode first with distilled water and then with the
second buffer.
6. Place the electrode into the second buffer. When the reading
is stable, set the meter to the pH value of the buffer at the
measured temperature. Refer to the meter user guide for a
detailed procedure. Table 1 provides pH buffer values at various
temperatures.
Nominal
Buffer
Value at
25 °C
Temperature
0°C 5°C
10°C 20°C 30°C 40°C 50°C 60°C 70°C 80°C 90°C
1.68 1.67 1.67 1.67 1.68 1.68 1.69 1.71 1.72 1.74 1.77 1.79
4.01 4.00 4.00 4.00 4.00 4.02 4.03 4.06 4.09 4.12 4.16 4.21
6.86 6.98 6.95 6.92 6.87 6.85 4.03 6.83 6.84 6.85 6.86 6.88
7.00 7.11 7.08 7.06 7.01 6.98 6.97 6.96 6.97 6.99 7.03 7.08
9.18 9.46 9.40 9.33 9.23 9.14 9.07 9.01 8.96 8.92 8.89 8.85
10.01 10.32 10.25 10.18 10.06 9.97 9.89 9.83 9.79 9.78 9.78 9.80
12.46 13.47 13.24 13.03 12.64 12.29 11.99 11.73 11.50 11.30 11.13 11.98
Table 1: pH Values of Buffers at Various Temperatures

12 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
To minimize the chance of breakage, the 8220BNWP ROSS micro pH
electrode should be attached to an electrode stand and suspended in
a beaker that contains storage solution. The electrode should not touch
the side or bottom of the beaker.
Long Term Storage (more than one week)
For refillable pH electrodes, fill the reference chamber and securely
cover the fill hole. Cover the sensing bulb and reference junction with
the protective cap, sleeve or storage bottle containing a few drops of
storage solution. Before returning the electrode to use, prepare it as a
new electrode.
Electrode Maintenance
1. Inspect the electrode for scratches, cracks, salt crystal
buildup or membrane/junction deposits.
2. Rinse off any salt buildup with distilled water. Remove any
membrane/junction deposits as directed in the General Cleaning
section.
3. If a refillable electrode is used, drain the reference chamber, flush
it with fresh ROSS fill solution and refill the chamber with fresh
ROSS fill solution.
Electrode Cleaning Procedures
General Cleaning
We offer a variety of Orion pH cleaning solutions for your convenience,
including solutions for general cleaning, protein removal, bacteria
removal, and oil and grease removal. See the list of Orion cleaning
solutions below the General Cleaning section of this manual. If you
would like to prepare your own cleaning solutions, the general cleaning
procedures contain several recommendations.
pH Measurements
1. Calibrate the electrode as described in the Electrode Calibration
section.
2. Rinse the electrode with distilled water and then with the sample.
3. Place the electrode into the sample.
4. When the reading is stable, record the pH and temperature of the
sample.
Electrode Storage
To ensure a quick response and free flowing junction, the sensing bulb
and reference junction must not dry out.
Short Term Storage (up to one week)
Soak the electrode in ROSS pH electrode storage solution, Cat. No.
810001, or standard pH electrode storage solution, Cat. No. 910001.
For enhanced electrode performance, use ROSS pH electrode storage
solution.

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |13 Thermo Scientic Orion
1. a. For general cleaning, prepare a 0.1 M hydrochloric acid (HCl)
or 0.1 M nitric acid (HNO3) solution.
b. For cleaning oil or grease, prepare a 0.1 to 0.5 % liquid
detergent solution mixed with hot water.
c. For cleaning bacterial contaminants, prepare a 1:10 dilution of
household laundry bleach.
2. a. Soak the electrode in the 0.1 M HCl or HNO3for half an hour
and stir the solution at a moderate rate.
b. Soak the electrode in the 1:10 dilution of household laundry
bleach or the 0.1 to 0.5% liquid detergent solution mixed with
hot water for 15 minutes and stir the solution at a moderate
rate.
3. If a refillable electrode is used, drain the reference chamber and
refill the electrode with fresh ROSS fill solution.
4. Soak the electrode in ROSS pH electrode storage solution, Cat.
No. 810001, or standard pH electrode storage solution, Cat. No.
910001, for at least one hour.
Cleaning Solutions
Cat. No. 900021-WA: pH cleaning solution A for removing protein
contaminants.
Cat. No. 900022-WA: pH cleaning solution B for removing bacterial
contaminants.
Cat. No. 900023: pH cleaning solution C for general cleaning.
Cat. No. 900024: pH cleaning solution D for removing oil and grease
contaminants.
Cat. No. 900020: pH cleaning solution kit, includes cleaning solutions
A, B, C and D.
Electrode Characteristics
Temperature Effects
The most common cause of error in pH measurements is temperature.
There are at least five ways that temperature variations can affect
pH: electrode slope, buffers, samples, reference element drift, and
temperature sensor errors.
Electrode Slope Changes
The electrode slope will change with variations in temperature.
Slope changes may be compensated manually, automatically with
an automatic temperature compensation (ATC) probe or with LogR
technology using a LogR enabled meter and any Orion electrode.
Thermo Scientific Orion pH meters calculate the slope based on the
measured temperature and automatically adjust the pH value based on
the temperature.

14 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Buffer and Sample pH Changes
Buffer and sample pH values change with temperature because of
their temperature dependent chemical equilibria. The pH electrode
should be calibrated with buffers that have known pH values at different
temperatures. Buffer values at different temperatures are given in
Table 1.
Orion pH meters automatically calibrate with the correct pH buffer
values based on the measured temperature. All pH meters are unable
to correct sample pH values back to a reference temperature because
every sample has a unique pH value versus temperature relationship.
Therefore, calibration and measurements should be performed at the
same temperature and pH values should be reported with temperature.
Reference Element Drift
Drift can occur when the internal reference elements inside the pH and
reference portions of the electrode are reaching thermal equilibrium
after a temperature change. Long-term drift or slow response can last
until the sample and electrode are at the same temperature.
ROSS electrodes use a unique internal reference to minimize the
equilibration time.
Temperature Sensor Errors
When a pH and ATC probe are placed into a sample that varies
significantly in temperature, the readings can drift for two reasons. First,
the temperature response of the electrode and temperature probe may
not be similar, which prolongs equilibration and drift. Second, a sample
may not have a uniform temperature. Therefore, the pH electrode and
temperature probe are responding to different environments. Stirring
the sample will minimize this effect.
Using LogR technology, Orion Versa star and Orion Dual star
meters calculate the temperature by measuring the resistance value
of the ROSS pH electrode’s sensing bulb. The pH and temperature
response is identical and both measurements occur at the sensing
bulb. Drift is minimized and errors due to environmental differences are
eliminated.
Sure-Flow Electrode Leak Rate
The junction of the ROSS Sure-Flow electrodes has been designed
to leak at a rate of approximately 1 mL per 24 hours. To keep the
junction from clogging, the leak rate is slightly higher than conventional
electrodes. During the average pH measurement time the loss of
fill solution is minimal and the fill solution does not contaminate the
sample.
ROSS Micro pH Electrode
The 8220BNWP ROSS micro pH electrode has been designed to
measure extremely small samples. The measuring tip is 3 mm in
diameter and 40 mm long. The minimum depth of immersion is 4.5 mm
and the minimum sample size is 15 µL in 384 well plates.

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |15 Thermo Scientic Orion
ROSS Ultra pH/ATC Triode Electrodes
The ROSS Ultra Triode electrode operating temperature range is 0
to 100°C and the temperature accuracy is ±1°C at 2 minutes when
immersed at least 2 inches in solution. The temperature equilibration
due to the rate of heat transfer can take up to 2 minutes in a stirred,
aqueous solution.
ROSS Electrode Operation with
Orion Versa star pH/LogR Meters
When ROSS electrodes are used with Orion Versa star pH/LogR
Meters, enhanced temperature compensation is achieved without
the need of a separate ATC probe. Using LogR technology, the
temperature of the solution is measured through the resistance value of
the pH electrode’s sensing bulb.
Each ROSS pH electrode must be calibrated for temperature before
a pH measurement is performed using LogR technology. Refer to the
Orion Versa star pH/LogR meter user guide for details. For maximum
precision, a three point temperature calibration is recommended. Do
not perform a one point temperature calibration if measured solutions
will be below 20°C. The following tables illustrate the expected
pH compensation error for one, two and three point temperature
calibrations. The accuracy values are valid only when the temperature
calibration is performed within the stated temperature range. The
higher temperature range data will apply to measurements made above
that temperature range, provided that calibration points are within 20°C
of each other. When highly accurate pH results are desired, a separate
ATC probe is recommended.
One Point Temperature Calibration
Electrode
Average
Temp. Error
20-30°C
Average
Temp. Error
30-50°C
Average
pH Error
20-30°C
Average
pH Error
30-50°C
8202BN 0.13 0.07 0.002 0.001
8203BN 0.24 0.17 0.003 0.002
8235BN 0.91 0.95 0.011 0.011
8256BN 0.09 0.10 0.001 0.001
Two Point Temperature Calibration
Electrode
Average
temp. error
0-25°C
Average
temp. error
20-40°C
Average
pH error
0-25°C
Average
pH error
20-40°C
8202BN 0.13 0.07 0.002 0.001
8203BN 0.24 0.17 0.003 0.002
8235BN 0.91 0.95 0.011 0.011
8256BN 0.09 0.10 0.001 0.001

16 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Three Point Temperature Calibration
Electrode
Average
temp. error
0-25°C
Average
temp. error
20-40°C
Average
pH error
0-25°C
Average
pH error
20-40°C
8202BN 0.04 0.03 0.000 0.000
8203BN 0.04 0.01 0.000 0.000
8235BN 0.07 0.06 0.001 0.001
8256BN 0.04 0.06 0.000 0.001
Electrode Interferences
Sodium ions are the principal interference of the pH electrode and
cause increasing error at higher pH (lower hydrogen ion activities) and
at higher temperatures. Because the pH membrane is composed of
special low sodium error glass, error due to sodium is negligible when
measuring at pH values less than 12. When measuring at pH values
greater than 12, add the correction value from the nomograph below to
the observed pH reading.
Typical Sodium Error
Example:
pH reading: 12.10
Sodium concentration: 0.5 M
Temperature: 50°C
Correction: 0.01
Corrected pH reading: 12.11
10
11
12
13
80
70
60
50
40
30
°C 20 0.1 M
25 0.5 M
1 M
2 M
5 M
5 M
0.5 M
0.1 M
1 M
2 M
20°C
25
30
40
50
60
70
80
0.70
0.60
0.50
0.40
0.30
0.25
0.20
0.15
0.10
0.08
0.06
0.05
0.04
0.03
0.02
0.01
0.005
pH correction
to be added
Sample
pH reading
sample
sodium
concentration

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |17 Thermo Scientic Orion
Troubleshooting
Follow a systematic procedure to isolate the problem. The pH
measuring system can be divided into four components: pH meter,
electrode, sample/application and technique.
pH Meter
The meter is the easiest component to eliminate as a possible cause of
error. Orion pH meters include an instrument checkout procedure and
shorting cap for convenience in troubleshooting. Refer to the pH meter
user guide for directions.
Electrode
To test electrode operation:
1. Connect the electrode to a working meter that has a mV measuring
mode. Set the meter to the mV mode.
2. Rinse the electrode with distilled water and then insert the
electrode into fresh pH 7 buffer. When the reading is stable, record
the mV value of the pH 7 buffer. The mV value should be in the
range of -30 to +30 mV.
3. Rinse the electrode with distilled water and then insert the
electrode into fresh pH 4 buffer. When the reading is stable, record
the mV value of the pH 4 buffer. The mV value should be in the
range of +150 to +210 mV.
4. Calculate the absolute mV difference between the two buffers. The
mV difference should be 160 to 180 mV. The actual mV values will
change as the electrode ages, but the mV difference between the
two buffers should always be 160 to 180 mV.
5. If the electrode fails this procedure, clean the electrode thoroughly
as directed in the Electrode Maintenance section and repeat the
procedure.
If the electrode response is slow or drifting and the electrode is
refillable, drain and refill the electrode with fresh ROSS fill solution, Cat.
No. 810007.
Replace the electrode if cleaning and maintenance fail to rejuvenate it.
Sample/Application
The electrode and meter may operate with buffers, but not with the
sample. In this case, check the sample composition for interferences,
incompatibilities or temperature effects. Refer to the Interferences
section.
Technique
If trouble persists, review operating procedures. Review the calibration
and measurement sections to be sure proper technique has been
followed.

18 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Assistance
After troubleshooting all components of your measurement system,
contact Technical Support. Within the United States and Canada, call
1.800.225.1480 or 978.232.6000 or email
[e-mail]. For countries outside of North
America, contact your local authorized dealer.
Warranty
For the most current warranty information, visit
www.thermoscientific.com/WaterWarranty
RoHS Statement
部件名称
Part Name
有毒或有害物质和元素
Toxic or Hazardous Substances and Elements
铅 Lead (Pb) 汞 Mercury (Hg) 镉 Cadmium (Cd)
传感器体带电
缆装配
Sensor body with
cable assembly
X 0 0
塑料硬件
Plastic hardware 0 0 0
部件名称
Part Name
有毒或有害物质和元素
Toxic or Hazardous Substances and Elements
六价铬
Hexavalent
Chromium
(Cr(VI))
多溴联苯
Polybrominated
biphenyls (PBB)
多溴二苯醚
Polybrominated
diphenyl ethers
(PBDE)
传感器体带电
缆装配
Sensor body with
cable assembly
0 0 0
塑料硬件
Plastic hardware 0 0 0
0: 表明本部件的所有均相材料内该有毒或有害物质的含量低于根
据 EIP-A, EIP-B, EIP-C 在SJ/T11363-2006 里的限制规定.
Indicates that this toxic or hazardous substance contained in all homogeneous
materials for this part, according to EIP-A, EIP-B, EIP-C is below the limit
requirement in SJ/T11363-2006.
X: 表明本部件有至少一样均相材料内该有毒或有害物质的含量
高于根据 EIP-A, EIP-B, EIP-C 在SJ/T11363-2006 里的限制规定.
Indicates that this toxic or hazardous substance contained in at least one of
the homogeneous materials used for this part, according to EIP-A, EIP-B,
EIP-C is above the limit requirement in SJ/T11363-2006

Thermo Scientic ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes |19 Thermo Scientic Orion
Ordering Information
Cat. No. Description
8102BNUWP ROSS Ultra combination pH electrode with glass body,
waterproof BNC connector
8302BNUMD ROSS Ultra rellable pH/ATC Triode with glass body,
waterproof BNC and 8 pin miniDIN connectors
8302BNURCA
ROSS Ultra rellable pH/ATC Triode with glass body,
waterproof BNC and RCA connectors (for use with Five and
Seven Series METTLER TOLEDO pH meters)
8103BNUWP ROSS Ultra combination pH electrode with glass body and
semi-micro tip, waterproof BNC connector
8104BNUWP ROSS Ultra combination pH electrode with glass body and
rugged bulb, waterproof BNC connector
8107BNUMD ROSS Ultra gel-lled pH/ATC Triode with epoxy body,
waterproof BNC and 8 pin miniDIN connectors
8107BNURCA
ROSS Ultra gel-lled pH/ATC Triode with epoxy body,
waterproof BNC and RCA connectors (for use with Five and
Seven Series METTLER TOLEDO pH meters)
8107UWMMD
ROSS Ultra gel-lled pH/ATC Triode with epoxy body,
waterproof BNC and 8 pin miniDIN connectors and 3 meter
cable
8115BNUWP ROSS Ultra combination pH electrode with epoxy body and
semi-micro tip, waterproof BNC connector
8135BNUWP ROSS Ultra combination pH electrode with epoxy body and
at surface tip, waterproof BNC connector
8156BNUWP ROSS Ultra combination pH electrode with epoxy body,
waterproof BNC connector
8157BNUMD ROSS Ultra rellable pH/ATC Triode with epoxy body,
waterproof BNC and 8 pin miniDIN connectors
8157BNURCA
ROSS Ultra rellable pH/ATC Triode with epoxy body,
waterproof BNC and RCA connectors (for use with Five and
Seven Series METTLER TOLEDO pH meters)
8157UWMMD
ROSS Ultra rellable pH/ATC Triode with epoxy body,
waterproof BNC and 8 pin miniDIN connectors and 3 meter
cable
800500U ROSS Ultra reference half-cell electrode with glass body, pin
tip connector
800300 ROSS Sure-Flow reference half-cell electrode with glass
body, pin tip connector
8101BNWP ROSS pH half-cell electrode with glass body, waterproof
BNC connector
8101SC ROSS pH half-cell electrode with glass body, screw cap
connector
8102BN ROSS combination pH electrode with glass body, BNC
connector
8102SC ROSS combination pH electrode with glass body, screw cap
connector
8103BN ROSS combination pH electrode with glass body and
semi-micro tip, BNC connector
8103SC ROSS combination pH electrode with glass body and
semi-micro tip, screw cap connector

20 |ROSS Ultra, ROSS Ultra Triode and ROSS pH Electrodes Thermo Scientic Orion
Cat. No. Description
8104BN ROSS combination pH electrode with glass body and rugged
bulb, BNC connector
8104SC ROSS combination pH electrode with glass body and rugged
bulb, screw cap connector
8115BN ROSS combination pH electrode with epoxy body and
semi-micro tip, BNC connector
8115SC ROSS combination pH electrode with epoxy body and
semi-micro tip, screw cap connector
8135BN ROSS combination pH electrode with epoxy body and at
surface tip, BNC connector
8135SC ROSS combination pH electrode with epoxy body and at
surface tip, screw cap connector
815600 ROSS combination pH electrode with epoxy body, BNC
connector
8155SC ROSS combination pH electrode with epoxy body, screw cap
connector
8162SC ROSS combination pH electrode with glass body and 14/15
standard taper, screw cap connector
8163BNWP ROSS combination pH electrode with glass body and spear
tip, waterproof BNC connector
8163SC ROSS combination pH electrode with glass body and spear
tip, screw cap connector
8165BNWP ROSS Sure-Flow combination pH electrode with epoxy body,
waterproof BNC connector
8165DN ROSS Sure-Flow combination pH electrode with epoxy body,
E DIN waterproof connector
8172BNWP ROSS Sure-Flow combination pH electrode with glass body,
waterproof BNC connector
8175BNWP ROSS Sure-Flow combination pH electrode with epoxy body,
semi-micro tip and waterproof BNC connector
8220BNWP ROSS combination pH electrode with glass body, micro tip
and waterproof BNC connector
810007 ROSS pH electrode ll solution, 5 x 60 mL bottles
810001 ROSS pH electrode storage solution, 475 mL bottle
910001 pH electrode storage solution, 475 mL bottle
810199
All-in-One ROSS pH buffer kit, includes 475 mL bottle each
of pH 4.01, 7.00 and 10.01 buffers, 475 mL bottle of ROSS
pH electrode storage solution, 30 mL bottle of pH electrode
cleaning solution C and 12 mm electrode storage bottle
910168 pH 1.68 buffer, 475 mL bottle
910104 pH 4.01 buffer, 475 mL bottle
910105 pH 5.00 buffer, 475 mL bottle
910686 pH 6.86 buffer, 475 mL bottle
910107 pH 7.00 buffer, 475 mL bottle
910918 pH 9.18 buffer, 475 mL bottle
910110 pH 10.01 buffer, 475 mL bottle
910112 pH 12.46 buffer, 475 mL bottle
900020
pH electrode cleaning solution kit, includes 1 x 30 mL bottle
each of cleaning solution A and C, 1 x 60 mL bottle each of
cleaning solution B and D, pipette and beaker