L-type Lujin capillary L sand core salt bridge extended salt bridge

Regarding dimensions:

Old Lujin capillary tube - equipped with a reference electrode with a diameter of 6-7mm - outer diameter of 10.5mm

Straight ceramic core salt bridge - equipped with 6-7mm diameter reference electrode - lower end diameter 6mm, upper end diameter 10.5mm

L-type ceramic core salt bridge - equipped with 6-7mm diameter reference electrode - outer diameter 1.05mm

L-type ceramic core salt bridge - equipped with a reference electrode with a diameter of 3.8-4.0mm - outer diameter of 6mm

Advantages of ceramic sand core:

The bottom end adopts ceramic sand core for liquid infiltration, with stable potential and good testing effect

2. Easy to operate, simply fill the reference electrode solution directly

3. Easy to clean and reuse

Ceramic core salt bridge: directly fill the reference electrode solution to one-third of the height.

Luggin Capillary

Property: When there is current passing through the measuring battery, the solution between the two electrodes exists

When the Ohmic potential drops, for solutions with higher resistivity and higher current, more

To be significant. In order to minimize its impact on potential measurement, the reference electrode is used

Pull the glass tube at the extreme solution end into a capillary tube, namely a Lujin capillary tube, and make it

Try to get as close to the working electrode as possible, so that there is almost no measurement circuit in the reference electrode

The current passes through, so that a high resistance voltmeter can be used to measure the more accurate potential number

According to.

Function: The function of Lujin capillary is to eliminate resistance overpotential; Three electrodes

(Test electrode, auxiliary electrode, reference electrode), auxiliary electrode and test electrode

Electrode, change the resistance in the circuit, control the current density of the tested electrode, and obtain

To different overpotentials; The reference electrode and the electrode to be tested are measured using the counter elimination method

Measure the potential of the electrode.

Usage: The Lujin capillary tip should be placed as close as possible to the surface of the research electrode, as much as possible

Can reduce the Ohmic potential drop. But it cannot be too close, otherwise it will affect the electricity

The polar surface produces a significant shielding effect, affecting the distribution of current. In order to both reduce

The low ohmic voltage drop of the solution without producing a significant shielding effect can make it sharp

The distance between the mouth and the surface of the research electrode shall not be less than the outer diameter of the Lujin capillary.

2 Preparation, use, and maintenance

[1] 1. Add 3 grams of agar and 97ml of distilled water to the beaker, and then add them to the water bath

Heat until * dissolves. Then add 30 grams of KCl and stir thoroughly until KCl * dissolves

After dissolving, use a dropper or siphon to add this solution to the pre bent glass while it is still hot

In the tube, let it stand and wait for the agar to solidify before use.

2. Agar saturated KCl salt bridge cannot be used for Cl - ions containing Ag+, Hg2+, etc

A solution containing ions or substances such as ClO4- that interact with K+.

3. Testing above 80 ℃ will cause damage to the salt bridge, control the test

The temperature is below 70 ℃.

4. After the experiment is completed, the salt bridge needs to be rinsed with deionized water to avoid contaminating the electricity

Extreme, then soak in a saturated KCl solution. Pay attention to regularly supplementing with deionized water

Water is used to prevent the salt bridge from cracking and being damaged.

5. After the experiment is completed, the saturated calomel electrode should be immersed in a saturated KCl solution

To prevent the deterioration of the composite electrode replenishment solution. In the future, it should be used

First, check if the supplementary solution inside the electrode is saturated (usually there may be some issues inside)

Saturated KCl crystals).

6. Attention: It is strictly prohibited to store the beaker containing saturated calomel electrode and salt bridge

The dropper placed in it must not be used for other purposes.