Why is Ag AgCl a good reference electrode?
Silver-Silver Chloride (Ag/AgCl) Electrodes are known for their low offset voltage, low noise and stability.
Are the Ag AgCl electrodes reusable?
Unlike plated or chlorided silver, the Ag/AgCl electrodes are homogeneous and solid throughout. Should the surface become damaged or contaminated, a new surface can be exposed to restore the electrode’s original performance.
What are the Electrical Specifications?
Following are typical values of key parameters between pairs of electrodes of the same size measured after prolonged soaking in 0.9% saline. These are median values from a large sample:
DC offset Voltage (biaspotential): 180 µV, Drift: 25 µV / h (at constant temperature) Noise: 1 µV P – P (0.1 – 1 (0.l – l kHz with 60 Hz filtered out) Polarization (counter EMF): 2 – 4µV at 0.1 µA
How do we make our Ag AgCl reference electrodes?
The BioMed Electrode is manufactured through a proprietary process using the highest purity chemicals that results in a fine grain homogeneous mixture, no fillers or binders are used- only pure silver-silver chloride. The electrodes are then compressed into a 1mm thick sensor and “sintered” (heat treated) for strength and stability. Standard lead wires are PVC insulated multi-strand copper with internal Tinsel for additional strength. The result is a versatile and durable, waterproof assembly that is reusable and re-surfacable.
They are easily reshaped by drilling, cutting or sanding.
Are Sintered Ag AgCl Electrodes superior in performance?
Sintered silver/silver chloride electrodes are recognized worldwide as a stable, low noise reference electrodes. They are reversible, which means they can pass an electric current without changing the chemical environment in the immediate vicinity of the electrode. This is not true of metal electrodes. This reversibility requires a soluble chloride containing electrolyte gel or paste.
Because the sintered silver/silver chloride electrodes exhibit low noise and theoretically zero electrode polarization impedance effects. They have much lower DC offset potentials than metal electrodes and provide excellent low frequency response.
Why is silver used as a reference electrode?
Silver is the best electrical conductor of all the metals because it has the lowest electrical resistance. The silver wire, coated in silver chloride, is relatively insensitive to changes in temperature.
Why are Ag AgCl electrodes used?
Silver/silver chloride is a common choice of biological electrodes due to its low half-cell potential of about +222 mV (SHE), low impedance, with a toxicity lower than that of the calomel electrode containing mercury.
Is AgCl conductive?
Wet AgCl is a solid ionic conductor. With DC current flow, the AgCl layer will increase in thickness if it is deposited on silver metal anode.
Is AgCl a precipitate?
A solution of silver nitrate is combined with a solution of sodium chloride. The resulting solution contains Na+, Ag+, Cl-, and NO3-, but AgCl is not soluble in water. Since Ag+ is now in solution with Cl- the two will combine to form AgCl, and the AgCl will precipitate from solution.