Thermo Scientific 8102BNUWP, 8103BNUWP, 8257BNU, 8302BNUMD, 8207BNU Instruction Manual

Orion ROSS Ultra

pH Electrode

INSTRUCTION MANUAL

pH

Orion 8102BNU, 8102SCU,
8103BNU, 8103SCU,
8104BNU, 8104SCU,
8115BNU, 8115SCU,
8135BNU, 8135SCU,
8156BNU, 8156SCU,
800500U

®

ROSS and the COIL trade dress are trademarks of Thermo Electron Corporation

Analyze • Detect • Measure • Control

™

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AQUAfast, Cahn, EZ Flash, Ionalyzer, ionplus, KNIpHE, No Cal, ORION, perpHect,
PerpHecT, PerpHecTion, pHISA, pHix, pHuture, Pure Water, Sage, Sensing the
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and Wine Master are registered trademarks of Thermo Electron Corporation.

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PerpHecT meters are protected by U.S. patent 6,168,707.

PerpHecT ROSS are protected by U.S. patent 6,168,707.

ORION Series A meters and 900A printer are protected by U.S. patents
5,108,578, 5,198,093 and German patents D334,208 and D346,753.

Sure-Flow electrodes are protected by European Patent 278,979
and Canadian Patent 1,286,720.

ionplus electrodes and Optimum Results solutions are protected by
US Patent 5,830,338.

ROSS Ultra electrodes have patents pending.

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© Copyright 2004, Thermo Electron Corporation. All rights reserved. Question
everything, and Analyze.Detect.Measure.Control are trademarks of Thermo
Electron Corporation.

The specifications, descriptions, drawings, ordering information and part
numbers within this document are subject to change without notice.

This publication supersedes all previous publications on this subject.

TABLE OF CONTENTS

General Information 1

Introduction 1
Required Equipment 2
Required Solutions 2

Using the Electrode 3

Electrode Preparation 3
Sample Requirements 4
Measuring Hints 5

pH Calibration & Measurement 7

General Calibration Procedure 7
Single Buffer Calibration 7
Two-Buffer Calibration 8
pH Measurement 9
Electrode Storage 9
Electrode Maintenance 10
Cleaning Electrode 10

Troubleshooting 11

Troubleshooting Guide 11
Assistance 12

Electrode Characteristics 13

Temperature Effects 13
Interferences 13

Ordering Information 15

Electrode 15
Accessories 26

Specifications 17

1

GENERAL INFORMATION

Introduction

This manual contains instructions for the Orion ROSS Ultra®series
of pH electrodes. Operation and maintenance instructions for the
following electrodes are included.

Orion Description

800500U ROSS Ultra Reference Electrode, glass body, pin tip

8102BNU ROSS Ultra Combination pH Electrode, 0-14 pH,

glass body, BNC

8103BNU ROSS Ultra Combination Semi-micro pH Electrode,

0-14 pH, glass body, BNC

8104BNU ROSS Ultra Combination pH Electrode, 0-14 pH,

glass body with rugged bulb, BNC

8115BNU ROSS Ultra Combination Semi-micro pH Electrode,

0-14 pH, epoxy body, BNC

8135BNU ROSS Ultra Combination Flat Surface Electrode,

0-14 pH, epoxy body, BNC

8156BNU ROSS Ultra Combination pH Electrode, 0-14 pH,

epoxy body, BNC

8102SCU ROSS Ultra Combination pH Electrode, 0-14 pH,

glass body, SC*

8103SCU ROSS Ultra Combination Semi-micro pH Electrode,

0-14 pH, glass body, SC*

8104SCU ROSS Ultra Combination pH Electrode, 0-14 pH,

glass body with rugged bulb, SC*

8115SCU ROSS Ultra Combination Semi-micro pH Electrode,

0-14 pH, epoxy body, SC

8135SCU ROSS Ultra Combination Flat Surface Electrode,

0-14 pH, epoxy body, SC

8156SCU ROSS Ultra Combination pH Electrode, 0-14 pH,

epoxy body, SC

* Screw cap requires cable, Orion 91CBNC to connect to

BNC meters.

The ROSS Ultra series of electrodes provides 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.

2

Required Equipment

Meter — Any Orion pH or ion selective meter, or other pH/ISE meter

with appropriate connectors.

Electrode — ROSS Ultra

®

Combination electrodes or ROSS Ultra

reference electrode with ROSS 8101 ROSS pH Half-cell electrode.

ATC Probe — for temperature measurement. Select ATC probe
compatible with meter.

Beakers — Plastic or glass.

Magnetic Stirrer — Suggested for precision measurements.

Required Solutions

pH Buffers — Two are recommended for precise measurement. The

first, near the electrode isopotential point (pH 7) and the second
near the expected sample pH (e.g., pH 4 or 10).

ROSS

™

Internal Filling Solution - 3M KCl, Orion 810007. Do not use

any filling solution which contains silver. (Electrode damage
may result.)

Figure 1: Orion 8102BNU ROSS Ultra Combination Electrode

Fill Hole

ROSS Ultra

Internal Reference

pH Sensing Bulb

Filling Solution
Chamber

Ceramic
Reference Junction

USING THE ELECTRODE

Electrode Preparation

1. Remove the protective shipping cap from sensing element and
save for storage.

2. Clean any salt deposits from exterior by rinsing with
distilled water.

3. Uncover fill hole and add ROSS

™

Filling Solution,
Orion 810007, to electrode. See Figure 2. To maintain an
adequate flow rate, the level of filling solution must cover the
end of the coil and be at least one inch above the sample level
on immersion. The fill hole should be open whenever the
electrode is in use.

4. Place the electrode in the electrode holder and suspend in air
for 15 minutes to thoroughly wet the reference junction. Once
the junction is wet, do not allow the electrode to dry out.

5. Carefully shake down the electrode (as a clinical
thermometer) to remove air bubbles.

6. Soak electrode in pH Electrode Storage Solution,
Orion 910001, for one hour.

7. Connect electrode to meter.

Figure 2: Filling an Electrode

3

Sample Requirements

One of the benefits of the ROSS Ultra®pH Electrode is that the
reference electrode filling solution composition may be changed
depending on sample requirements.

The ROSS

™

pH Electrode Filling Solution, Orion 810007 is 3M KCl. For
solutions with components that precipitate in the presence of
chloride ion, the ROSS Ultra pH Electrode could be filled with 10%
KNO

3

, Orion 900003.

Samples should be aqueous if using epoxy body electrodes
(e.g., Orion 8115, 8135, 8156 ROSS Ultra electrodes).

In organic solutions, use an all glass ROSS Ultra Electrode (e.g.,
Orion 8102, 8103 and 8104 ROSS Ultra electrodes). For good results a
minimum of 20% water must be present in the sample. If there is a
great deal of drift when using the ROSS Ultra Electrode filled with
ROSS Filling Solution, Orion 810007, try filling the electrode with a
mixture of methanol and water saturated with KCl.

Figure 3: Measuring Hints

4

Fill hole should

be uncovered

Filling solution level
must be higher than
sample level

Fresh pH buffer

Stir all samples

and buffers

Reference junction
must be immersed in
sample or buffer

Place insulation
between stirrer
and beaker

Measuring Hints

See Figure 3

• Always use fresh buffers for calibration. Choose buffers that
are no more than 3 pH units apart.

• Check electrode slope daily by performing two buffer
calibration. Slope should be 92 to 102%.

• Only use ROSS

™

Internal Filling Solution, Orion 810007, for

ROSS Ultra

®

Combination pH Electrodes. Do not use any

filling solution which may contain silver.

• Remove fill hole cover during measurement to ensure uniform
flow of filling solution.

• Between measurements, rinse electrodes with distilled water
and then with the next solution to be measured.

• Stir all buffers and samples.

• Place a piece of insulating material (e.g., Styrofoam or
cardboard) between magnetic stirrer and beaker to prevent
error from transfer of heat to sample. Since ROSS Ultra
Electrodes respond faster than conventional electrodes,
changes in pH which result from temperature changes will be
noticed. See Electrode Characteristics.

• Avoid rubbing or wiping electrode bulb, to reduce chance of
error due to polarization.

• Orion 8135BNU may be used on any moist surface or in liquids.
See Figure 4.

Figure 4:
Use of Orion 8135BNU

567

pH CALIBRATION & MEASUREMENT

General Calibration Procedure

For detailed calibration and temperature compensation procedures,
consult your meter instruction manual.

Single Buffer Calibration

1. Choose a buffer near expected sample pH.

2. Buffer should be at same temperature as sample. If buffer and
samples are at varying temperatures, temperature
compensation is recommended.

3. Set up meter according to meter instruction manual.

4. Rinse electrode first with distilled water and then with the
buffer being used for calibration.

5. Place the electrode in the buffer. Wait for a stable display. Set
the meter to the pH value of the buffer at its measured
temperature. See Table 1. (A table of pH values at various
temperatures is supplied on the buffer bottle.) Proceed to pH

Measurement section.

Table 1
pH Values of Buffers at Various Temperatures

Nominal value at 25 ˚C Temperature

Buffer 0 ˚C 5 ˚C 10 ˚C 20 ˚C 30 ˚C

1.68 1.67 1.67 1.67 1.67 1.68

3.78 3.86 3.84 3.82 3.79 3.77

4.01 4.00 4.00 4.00 4.00 4.02

5.00 5.12 5.04 4.97

6.86 6.98 6.95 6.92 6.87 6.85

7.00 7.11 7.08 7.06 7.01 6.98

7.41 7.53 7.50 7.47 7.43 7.40

9.18 9.46 9.40 9.33 9.23 9.14

10.01 10.32 10.25 10.18 10.06 9.97

40 ˚C 50 ˚C 60 ˚C 70 ˚C 80 ˚C 90 ˚C

1.69 1.71 1.72 1.74 1.77 1.79

3.75 3.75

4.04 4.06 4.09 4.13 4.16 4.21

4.93 4.92 4.88

6.84 6.83 6.84 6.85 6.86 6.88

6.97 6.97 6.97 6.99 7.03 7.08

7.38 7.37

9.07 9.01 8.96 8.92 8.89 8.85

9.89 9.83

8

Two Buffer Calibration

This procedure is recommended for precise measurement.

1. Ensure that all buffers are at the same temperature. If samples
are at varying temperatures, temperature compensation is
recommended. (See Meter Instruction manual).

2. Select two buffers which bracket the expected sample pH. The
first should be near the electrode isopotential point (pH 7) and
the second near the expected sample pH (e.g., pH 4 or pH 10).

3. Rinse electrode first with distilled water and then with first
(pH 7) buffer.

4. Place the electrode in first (pH 7) buffer. Wait for a stable
display. Set the meter to the pH value of the buffer at its
measured temperature. (A table of pH values at various
temperatures is supplied on the buffer bottle). See Table 1.

5. Rinse electrode first with distilled water and then with the
second buffer.

6. Place the electrode in the second buffer. When display is
stable, set meter to the pH value of the buffer at its measured
temperature as described in the meter instruction manual.

7. If all steps are performed correctly, proceed to the pH
Measurement section. If any of the above procedures does not
work, refer to Troubleshooting.

9

pH Measurement

1. Calibrate the electrode as described in previous section.

2. Rinse the electrode with distilled water and then with sample.

3. Place the electrode in the sample.

4. When the display is stable, record sample pH.

Electrode Storage

To ensure a quick response and free-flowing liquid junction, the
sensing bulb and reference junction must not be allowed to dry out.

NOTE: The reference chamber should remain filled at
all times.

Short-term Storage (up to one week): Soak electrode in pH
Electrode Storage Solution, Orion 910001.

Long-term Storage: The reference chamber should be filled and the
filling hole securely covered. Cover the sensing element and
reference junction with its protective cap 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
build-up, or membrane/junction deposits.

2. Rinse off any salt build-up with distilled water, and remove
any membrane/junction deposits as directed in the cleaning
procedures below.

3. Drain the reference chamber, flush it with fresh ROSS

™

Filling

Solution, Orion 810007, and refill the chamber.

Cleaning Electrode

Thermo Electron offers Orion pH electrode cleaning kits in the
following configurations:

pH Cleaning Solution Sample Kit (Orion 900020) — Includes one

bottle each of cleaning solution A, B, C and D, 15 mL Beaker
and Pipette.

pH Cleaning Solution A (Orion 900021) — Protein removal.

pH Cleaning Solution B (Orion 900022) — Removal of bacterial

contaminant's.

pH Cleaning Solution C (Orion 900023) — General cleaning.

pH Cleaning Solution D (Orion 900024) — Removal of oil and grease

contaminant's.

10

11

TROUBLESHOOTING

Troubleshooting Guide

Follow a systematic procedure to isolate the problem. The pH
measuring system can be divided into four components for ease in
troubleshooting: pH meter, electrodes, sample/application,
and technique.

pH meter

The meter is the component which is easiest to eliminate as a
possible cause of error. Thermo Electron pH meters are provided
with an instrument checkout procedure and shorting cap for
convenience in troubleshooting. Consult your pH meter instruction
manual for directions.

Electrodes

To test electrode operation:

1. Connect electrode to a working meter.

2. Set function switch to absolute mV mode.

3. Immerse electrode in fresh pH 7 buffer.

4. Displayed value should be 0 ± 30 mV.

5. Rinse electrode and immerse in fresh pH 4 buffer.

6. Displayed value should be approximately 160 mV to 180 mV
greater than in step 4. (Actual mV values may change as
electrode ages, but mV differences will remain 160 to 180 mV).

If electrode fails this procedure, clean thoroughly as directed
in Maintenance.

If electrode response is slow or drifting, drain and refill with fresh
ROSS

™

Filling Solution, Thermo Electron Orion 810007. See
Measuring Hints. If cleaning and maintenance fail to rejuvenate the
electrode, replace the entire electrode.

Sample/Application

The electrode and meter may operate with buffers but not with your
sample. In this case, check sample composition for interferences,
incompatibilities, or temperature effects. Some samples, by their
nature, drift or change in pH.

Technique

If trouble persists, review operating procedures. Reread calibration
and measurement sections, to be sure proper technique has
been followed.

12

Assistance

For the most current warranty information, visit www.thermo.com.

After troubleshooting all components of your measurement system,
contact The Technical Edge

SM

for Orion products. Within the United

States call 1.800.225.1480, outside the United States call

978.232.6000 or fax [phone]. In Europe, the Middle East and
Africa, contact your local authorized dealer. For the most current
contact information, visit www.thermo.com.

13

ELECTRODE CHARACTERISTICS

Temperature Effects

The most common cause of error in pH measurement is
temperature. Ordinary electrodes drift with temperature changes.
The ROSS Ultra™pH Electrode eliminates the stability problems
associated with the use of conventional electrodes in samples of
varying temperature.

There are, however, two effects of temperature change that should
be kept in mind.

1. Electrode slope will change with varying temperature. This

slope change may be compensated for either manually, or
automatically with an automatic temperature compensator
(ATC) probe and properly designed pH meter. Consult your pH
meter instruction manual for details.

2. Buffer and sample pH values vary with temperature because

of the temperature dependent chemical equilibrium. The
problem of varying pH values is easily solved by calibrating
the electrode with characterized standard buffers whose true
pH values at different temperatures are known. Buffer values
at different temperatures are given in Table 1. The problem of
the sample equilibrium varying with temperature in an
uncharacterizable manner will always remain. Therefore, pH
values should be reported along with the temperature at
which the measurement was made.

Interferences

Sodium ion is the principle interference of the pH electrode, causing
increasing error at higher pH (lower hydrogen ion activities) and at
higher temperatures. Because the ROSS Ultra® 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 nomography in Figure 6 to the observed pH reading.

Figure 6: Typical Sodium Error Observed at pH > 12

Example:

pH reading 12.10
Sodium concentration 0.5 N
Temperature 50 ˚C
Correction 0.01
Corrected pH reading 12.11

14

Sample
pH reading

13

12

11

10

°C 20 0.1 M

25

0.5 M

30

40

50

60

70

80

0.1 M

0.5 M

1 M

1 M

2 M

2 M

sample
sodium

concentration

5 M

20°C
25

30

40

50

60

70

80

5 M

pH correction
to be added

0.005

0.01

0.02

0.03

0.04

0.05

0.06

0.08

0.10

0.15

0.20

0.25

0.30

0.40

0.50

0.60

0.70

15

ORDERING INFORMATION

Electrodes

Type of

Orion Description Connector

800500U ROSS Ultra

®

Combination pH Electrode, Pin Tip

glass body

8102BNU ROSS Ultra

®

Combination pH Electrode, BNC

glass body

8103BNU ROSS Ultra

®

Combination Semi-micro BNC

pH Electrode, glass body

8104BNU ROSS Ultra Combination pH Electrode, BNC

glass body with rugged bulb

8115BNU ROSS Ultra Combination Semi-micro BNC

pH Electrode, epoxy body

8135BNU ROSS Ultra Combination Flat Surface BNC

pH Electrode, epoxy body

8156BNU ROSS Ultra Combination pH Electrode, BNC

epoxy body

8102SCU ROSS Ultra Combination pH Electrode, Screw Cap

glass body Connector

8103SCU ROSS Ultra Combination Semi-micro Screw Cap

pH Electrode, glass body Connector

8104SCU ROSS Ultra Combination pH Electrode, Screw Cap

glass body with rugged bulb Connector

8115SCU ROSS Ultra Combination Semi-micro Screw Cap

pH Electrode, epoxy body Connector

8135SCU ROSS Ultra Combination Flat Surface Screw Cap

pH Electrode, epoxy body Connector

8156SCU ROSS Ultra Combination pH Electrode, Screw Cap

epoxy body Connector

16

Accessories

Orion Description

810007 ROSS

®

Internal Filling Solution, 3 M KCl,

five 50 mL bottles

910001 pH Electrode Storage Solution, 475 mL

910104 pH 4.01 Buffer, 475 mL

910107 pH 7.00 Buffer, 475 mL

910110 pH 10.01 Buffer, 475 mL

910410 perpHect

®

Buffer pH 4, 10 pk

910425 perpHect Buffer pH 4, 25 pk

910710 perpHect Buffer pH 7, 10 pk

910725 perpHect Buffer pH 7, 25 pk

910110 perpHect Buffer pH 10, 10 pk

910125 perpHect Buffer pH 10, 25 pk

911110 perpHect Electrode Rinse, 10 pk

911125 perpHect Electrode Rinse, 25 pk

900020 pH Cleaning Solution Sample Kit

900021 pH Cleaning Solution A – Protein Removal

900022 pH Cleaning Solution B – Bacterial Removal

900023 pH Cleaning Solution C – General Cleaning

900024 pH Cleaning Solution D – Removal of Oil and Grease

91CBNC Detachable Cable for Screw Cap Electrode,

with BNC Connector

91USCB Detachable Cable for Screw Cap Electrode,

with US Standard Connector

91CDIC Detachable Cable for Screw Cap Electrode,

with E DIN Connector

91CBRA Detachable Cable for Screw Cap Electrode,

with Radiometer No.7 Connector

17

SPECIFICATIONS

Length Electrodes

Electrodes* (excluding cap) Diameter

800500U 120 mm 12 mm

8102BNU 120 mm 12 mm
8102SCU 120 mm 12 mm

8103BNU 165 mm 6 mm**
8103SCU 165 mm 6 mm**

8104BNU 120 mm 12 mm
8104SCU 120 mm 12 mm

8115BNU 185 mm 8 mm***
8115SCU 185 mm 8 mm***

8135BNU 120 mm 12 mm
8135SCU 120 mm 12 mm

8156BNU 120 mm 12 mm
8156SCU 120 mm 12 mm

* ROSS Ultra

®

Electrodes operate in a 0-100 °C temperature
range,
0-14 pH range

** 6 mm section is 100 mm long

*** 8 mm section is 100 mm long

Isopotential points are at pH 7

Standard cap diameters are 16 mm and cap lengths are 30 mm

NOTES

18

Analyze • Detect • Measure • Control

244398-001 rev.A

™