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