Electrode holders

SXS measurements. (A) Single-crystal disk electrode, (B) Pt counter electrode, (C) Ag/AgCl reference electrode, (D) Mylar window, (E) electrolyte solution, (F) inlet for electrolyte solution, (G) outlet for electrolyte solution, (H) cell body, (1) micrometer, (J) electrode holder, (K) outer chamber, (b) Cell configuration for electrochemical measurement, (c) Cell configuration for SXRD measurement. (From Kondo et al., 2002, with permission from Elsevier.)... 

Fig. 1.3. Experimental setup for electrochemical thermal desorption mass spectroscopy (ECTDMS). C = electrochemical cell, W = working electrode, El = electrolyte inlet, EO = electrolyte outlet, EH = electrode holder, V = valve, TP = turbo pump, VC = vacuum chamber, L = light source, W = window, P = protective jacket, A = aperture to analysis chamber, GI = grid ion source, S = SEM detector.

In 1991 Mathiesen and Maahn published construction details of a modified form of the electrode holder used in ASTM G5 " (Fig. 16). The... 

In testing sheet, welded, and pipe material, the specimen is placed as a part of the bottom plate of the Avesta cell. Especially at higher temperatures there will be a difference between the temperature of the solution and the temperature of the specimen. This can be corrected for by calibration. When the modified ASTM G5 electrode holder is used, the specimen is totally immersed in the solution and no correction is needed. 

Figure 4.12 — (A) Flow-cell for the simultaneous determination of four analytes (1) ion-selective electrodes (2) reference electrode (3) Pt wire for grounding (4) Teflon gasket (5) carrier (6) inlet for reference solution (7) waste (8) screws (9) diecast box (10) rubber sheet for sealing. (B) Seven-electrode holder (the reference electrode is placed from the top into die central bore). ISEs for Na, K, Ca ", NOj", Cr, and HCO, (NH, electrode with internal buffer of 0.1 mmol/L NaHCOj) are placed horizontally around the reference electrode, the metal waste tubes being connected to the waste via filter-paper strips. (Reproduced from [124] and [108] with permission of Elsevier Science Publishers and VCH Publishers, respectively).

Once the paste is packed into the electrode body, the surface is polished on some mild abrasive such as an index card (historically an IBM computer card). Provided the face of the electrode holder is initially smooth, very reproducible electrode areas (less than 5% variation) and reactivities are attained. In fact, a major motivation for developing carbon paste electrodes was the ease of surface renewal and reproducibility. 

Place the electrode holder with the IEF electrodes on the electrophoresis apparatus and align electrodes over the center of the electrode strips. Connect the two electrodes to the base unit and place the lid on the apparatus. 

Figure 1. Schematic of experimental setup for measurements of the rotating ring-disk electrode (1) dual potentiogal-vanostat (2) ZnO disk electrode (3) Pt ring electrode (4) Teflon electrode holder (5) electrolytic cell (6) N2 gas inlet (7) Pt counter electrode (8) SCE (9) mirror ...

Fig. 5.11. Miniaturised complete LAPS device with integrated electronic unit. (1) LAPS-card with integrated LAPS sensor, (2) electronic unit, (3) light sources, (4) measurement chamber and (4) reference electrode holder.

Mount the tip of the micropipette in the electrode holder of the SECM translation stage. 

The cell consists typically of a 10-20 mL vessel and an electrode holder made of plastic or Teflon with holes for the working (W), reference (R) and counter (C) electrodes. In addition, there is an inlet for an inert gas, usually nitrogen or argon, by which the solution is purged before the measurements are made. Usually also, a gentle stream of the inert gas is maintained over the surface of the solution during the electroanalytical measurements. 

The number of rotations of the electrode holder is specified as follows ... 

Heliarc melding is used for stainless steels and most of the nonferrous materials. This process can be carried out manually, automatically, or semiauto-matically. A stream of helium or argon gas is passed from a nozzle in the electrode holder onto the weld, where the inert gas acts as a shielding blanket to protect the molten metal. As in the shielded-arc and submerged-arc processes, a filler rod is fed into the weld, but the arc in the heliarc process is formed between a tungsten electrode and the base metal. 

Electrode Assembly. This device consists of a specially machined Teflon electrode holder, two disc electrodes (only one is energized), and a clamp machined from acrylic plastic (Figure 3). The electrode discs are of low-temperature isotropic carbon alloyed with SiC (Carbo-metics, Austin, TX). They were originally developed for use in artificial heart valves (14), and are approximately 1.6 cm in diameter and 1.25 mm thick, and have the surface properties of glassy carbon. Treatment of the discs requires only polishing to a high lustre with diamond grinding compounds of 14,000 and 50,000 mesh. 

Procedure. A typical procedure such as that carried out on the Naval Ocean Systems Center s (NOSC) instrumented survey platform is as follows. The main sampling pump is started, and a continuous source of seawater is maintained aboard the craft. (This pumping system, which supplies large volumes of seawater for many different kinds of analytical measurements, is built into the survey platform and not discussed here.) The ASV operator then places fresh Hg solution in the Hg reservoir, selects a prepolished electrode, inserts it into the electrode holder, and turns the CO2 valve on. While O2 is being removed, the system automatically... 

QUARTZ ROD ELECTRODE HOLDER HINGE JOINT GEAR KNOB MOTOR... 

An appropriate amount of dendrimer dissolved in a suitable solvent can be mixed with a sufficient quantity of graphite powder. After evaporation of the solvent, the required quantity of the enzyme along with a small amount of paraffin oil are added and the mixture is blended into a paste. The modified carbon paste can be placed in an electrode holder and used [108],... 

Fig. 14.9 The sequential-parallel electroanalytical set-up showing the Faraday cage with the microtiter-plate compatible electrode system, relais board, personal computer, and potentiostat. The relais board and the electrode holder are magnified on the right.59 (Reproduced by permission of The Royal Society of Chemistry)...

---