Table of Contents
Advertisement
Advertisement
Table of Contents
Related Manuals for Thermo Scientific REDOX/ORP 9678BNWP
Summary of Contents for Thermo Scientific REDOX/ORP 9678BNWP
- Page 1 User Guide Redox/ORP Electrodes...
- Page 3 Introduction This user guide contains information on the preparation, operation and maintenance of the Thermo Scientific Orion ORP electrodes. These ORP electrodes combine a platinum redox sensing electrode and a silver/silver chloride reference electrode in one body. The redox/ORP electrodes can be used to make direct measurements of redox potentials or perform potentiometric titrations.
-
Page 4: Required Equipment
Required Equipment Thermo Scientific Orion pH/mV meter, such as the 3-Star pH meter, 4-Star pH/ISE meter, 4-Star pH/DO meter, 4-Star pH/conductivity meter or 5-Star pH/ISE/DO/conductivity meter. ORP electrodes can be used on any pH/mV meter with a BNC or U.S. standard connection. The electrodes can also be used on meters with a variety of inputs when an adapter cable is used. -
Page 5: Sample Requirements
Sample Requirements 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. The ORP electrodes contain a silver/silver chloride (Ag/AgCl) reference that may become clogged in solutions that contain silver complexing or binding agents such as TRIS, proteins and sulfides. -
Page 6: Electrode Preparation
Electrode Preparation Electrode Preparation for Refillable Electrodes Remove the protective shipping cap from the sensing element and save the cap for storage. Clean any salt deposits from the exterior of the electrode by rinsing with distilled water. Uncover the filling hole by removing the tape and then add electrode filling solution, Cat. - Page 7 filling hole filling hole Ag/AgCl internal reference Ag/AgCl internal reference sensing element sensing element Figure 1– Refillable ORP Electrode fill hole fill hole AgAgCl internal reference AgAgCl internal reference sensing element sensing element Figure 2– Sure-Flow Refillable ORP Electrode Redox/ORP Electrode User Guide filling solution chamber...
-
Page 8: Electrode Calibration
Electrode Calibration ORP readings can be reported using the absolute mV values or the E mV values. E mV values that would be obtained using a Standard Hydrogen Electrode (SHE), also known as the Normal Hydrogen Electrode (NHE). Orion ORP standard, Cat. No. 967901 or 967961, allows operators to correlate measurements to the E an Orion ORP electrode. - Page 9 Temperature (°C) (mV) Redox/ORP Electrode User Guide Value Absolute Value with Cat. No. 900011 Filling Solution (mV) Absolute Value with Cat. No. 900001 Filling Solution (mV)
-
Page 10: Measurement Techniques
Measurement Techniques • Always use fresh ORP standard for calibration. • If the electrode is refillable, remove the filling hole cover during measurements to ensure a uniform flow of filling solution. • Between measurements, thoroughly rinse the electrode with distilled water. Gently shake the electrode after rinsing to prevent solution carryover and then blot the electrode dry with a lint-free tissue. -
Page 11: Direct Measurements
Electrode Measurements Direct Measurements Direct oxidation-reduction potential (ORP) measurements can be used to determine the oxidizing or reducing capability of a solution and are commonly made in polluted streams, chlorinated waters, industrial wastewaters and other water samples. Prepare the electrode according to the Electrode Preparation section. - Page 12 Oxidation-Reduction Titrations Oxidation-reduction or redox titrations provide a simple, reliable method for determining many substances in solution. A redox titration consists of adding to an unknown sample small increments of a titrant that converts the unknown to a different oxidation state. After each addition of titrant, the platinum redox electrode develops a potential proportional to the logarithm of the ratio of the activities of the two oxidation states.
- Page 13 Calculate the normality of the sample, N liter. = (V where: = normality of titrant (Eq/1) = volume of titrant at end point (mL) = volume of sample (mL) Table 2 References: Furman (ed.), Scott’s Standard Methods of Chemical Analysis, 5th Ed., Van Nostrand, Princeton, N.J. 1938. Hillebrand, Lundell, Bright, and Hoffman, Applied Inorganic Analysis, 2nd Ed., Wiley, New York, 1953.
- Page 14 Table 2– Typical Redox Titration Methods Unknown antimony (Sb arsenic (As hydrogen peroxide hypochlorite ion (ClO or chlorine (Cl iodine (I iodine (I iron (as Fe , Fe or in steel) iron (as Fe , Fe or in steel) manganese (as permanganate Mn0 manganese (as Mn stannous tin (Sn...
- Page 15 Suitable Titrants potassium permanganate (KMnO sodium bromate (NaBrO potassium permanganate (KMnO sodium iodide (NaI) sodium iodate ( NaIO sodium thiosulfate ceric sulfate [Ce(SO (not recommended for samples containing Cl¯) potassium dichromate ), recommended for samples containing Cl¯ ferrous sulfate (FeSO potassium permanganate (KMnO ceric sulfate [Ce(SO...
-
Page 16: Electrode Maintenance
Electrode Maintenance Inspect the electrode for scratches, cracks, salt crystal buildup, or membrane/junction deposits. Rinse off any salt buildup with distilled water. Remove any membrane/junction deposits as directed in the General Cleaning section. If the electrode is refillable, drain the reference chamber, flush it with fresh filling solution and refill the chamber with fresh filling solution. -
Page 17: Electrode Cleaning Procedures
Electrode Cleaning Procedures General Cleaning Soak the electrode in 0.1 M HCl or HNO The electrode can also be soaked for 15 minutes in a 1:10 dilution of household laundry bleach or a 0.1 to 0.5% liquid detergent solution mixed with hot water. The solution should be stirred at a moderate to fast rate. - Page 18 Sure-Flow Electrode Cleaning Cat. No. BNWP and 00 If the area between the electrode sleeve and inner cone becomes clogged with sample or precipitate, flush the area with filling solution or distilled water. Hold the electrode body with one hand and use your thumb to push down on the electrode cap to drain the chamber.
-
Page 19: Electrode Storage
Reassembling the Sure-Flow Electrode Moisten the O-ring on the electrode body with a drop of filling solution. Insert the screw-thread end of the electrode body into the tapered, ground end of the sleeve. Push the body into the sleeve using a gentle twisting motion until the bottom surface of the inner cone is flush with the tapered end of the sleeve. -
Page 20: Troubleshooting
Troubleshooting Follow a systematic procedure to isolate the problem. The measuring system can be divided into four components for ease in troubleshooting: meter, electrode, sample/application and technique. Meter The meter is the easiest component to eliminate as a possible cause of error. Thermo Scientific Orion meters include an instrument checkout procedure and shorting cap for convenience in troubleshooting. -
Page 21: Warranty
Checking Electrode Operation Checking the electrode is necessary only when there is evidence of malfunction that cannot be traced to other causes. Fill the electrode with Cat. No. 900011 filling solution for this testing procedure. Prepare solution A (0.1 M potassium ferrocyanide and 0.05 M potassium ferricyanide): weigh out 4.22 g reagent-grade Fe(CN) •3H... -
Page 22: Ordering Information
Ordering Information Cat. No. Description 9179BNMD Low maintenance gel ORP/ATC Triode with epoxy body and waterproof BNC and 8 pin MiniDIN connectors Low maintenance gel ORP/ATC Triode with 9179BN epoxy body and BNC and 8 pin DIN connectors Refillable ORP/ATC Triode with epoxy body and 9180BNMD waterproof BNC and 8 pin MiniDIN connectors 9180BN... - Page 23 Thermo Fisher Scientific Environmental Instruments Water Analysis Instruments 166 Cummings Center Beverly, MA 01915 USA Tel: 978-232-6000 Toll Free: 800-225-1480 Dom. Fax: 978-232-6015 Int’l. Fax: 978-232-6031 www.thermo.com/water 254794-001 Rev.A...
Need help?
Do you have a question about the REDOX/ORP 9678BNWP and is the answer not in the manual?
Questions and answers