PERMIT ion migration analyzer - a specialized equipment for on-site testing of the resistance of surface concrete to chloride ion diffusion
PERMIT can be used for non-destructive testing of the ability of surface concrete and various other building materials (including natural stone) to resist various ion diffusion.
This instrument can directly detect and evaluate concrete on site, avoiding the trouble of taking cores from structures and conducting testing in the laboratory.
PERMIT can be used both on-site and in the laboratory.
It can quickly detect and evaluate the ability of reinforced concrete structures to resist ion diffusion, which can be used to predict the service life of the structure.
Especially used to evaluate the corrosion damage of steel bars induced by chloride ions.
The product is lightweight, easy to use, and does not cause damage to the structure.
Even for testing concrete with extremely low permeability visible in current structures, the test can be completed on-site within one day.
The effectiveness of mineral admixtures such as fly ash and silica fume in improving the resistance of concrete to chloride ion diffusion can be evaluated.
Developed from years of research achievements with international standards.

Background Introduction
The invasion of chloride ions is the main cause of deterioration in reinforced concrete and prestressed reinforced concrete. Chloride ions usually penetrate the surface concrete in a water-soluble form. Under normal circumstances. The diffusion mechanism is the main kinetic transport mechanism for chloride ions (which are actually used for most ions) to penetrate the surface concrete. Although the ability of concrete to resist ion invasion can be evaluated through on-site coring and subsequent testing. However, it can cause damage to concrete structures and is extremely inconvenient to address this issue. Queen's University Belfast has developed the PERMIT ion migration instrument based on years of internationally advanced research achievements. This device can detect and evaluate the ability of concrete to resist ion invasion on site.

Application scope
􀁺 Evaluate the ability of concrete to resist chloride ion invasion
Measure the diffusion coefficient of chloride ions to predict the structural lifespan.
􀁺 Predict the corrosion of steel bars in concrete caused by salts.
Evaluate the ability of joint materials, ground rust coatings, and surface water treatment to resist chloride ion invasion.
Evaluate the impact of curing methods on the performance of concrete.
􀁺 Determine the impact of special templates, such as permeability control templates, on the performance of concrete.
􀁺 Determine the effect of shrinkage and settlement cracking on the resistance of concrete to chloride ion penetration.
􀁺 Can be used to test the diffusion coefficient of chloride ions

Range
PERMIT can be used to test various common building materials with ion diffusion coefficients ranging from 1 × 10m/s to 1 × 10m/s. The measurement time required for a single experiment using the PERMIT ion mobility analyzer fluctuates depending on the mass of the material being tested, typically ranging from 1.5 to 10 hours (the better the mass, the longer the required time).
The diffusion of chloride ions is related to the corrosion of steel bars induced by chloride ions, and can therefore be used in structural life models to predict their service life
02 Other ions PERMIT ion migration analyzer can also be used to evaluate damage caused by other ions (such as sulfates)

Working principle
The PERMIT ion migration analyzer is a uniquely designed testing instrument for evaluating the resistance of concrete and other building materials to ion invasion in laboratories and on site. The PERMIT host part consists of an inner chamber and an outer chamber, with the inner chamber injected with an ionic solution (such as: NaCl）， Distilled water is injected into the outer chamber, and by applying a voltage between the inner and outer chambers, ions can migrate from the inner chamber to the outer chamber. The rate at which ions reach the outer chamber (i.e. neutral solution) is determined by measuring the conductivity of the outer chamber.
Once the steady flow state is reached, samples can be taken from the outer chamber to determine the ion concentration. The ion diffusion rate (or ion diffusion coefficient) can be obtained by a computer using steady flow rate and Nernst Planck equation.

Instrument composition
The PERMIT ion migration analyzer is stored in a portable suitcase. The instrument consists of two parts: PERMIT host and electronic control and data collector
Figure 2a PERMIT ion migration analyzer Figure 2b Bolt fixation method Figure 2c Clamp fixation method
(Figure 2a), the PERMIT host can be fixed to the tested area with bolts or clamps (as shown in Figures 2b and 2c). This experiment can be conducted both horizontally and vertically.

The PERMIT host includes the following components: an electronic control system used to accurately provide operating voltage, stir outdoor solutions, and test the temperature and electrical conductivity of the outdoor solution.
Two working containers (or studios), one for injecting sufficient ionic solution and the other for injecting neutral solution (such as deionized water). A fastening ring used to secure the instrument to the testing surface, which can be fixed by bolts or similar inserts. Other necessary equipment for connecting electronic control systems. The electronic control system includes all specially designed electronic control components and data recording systems. Its surface is a LCD display screen and a test selection button. There are two sockets at the back of the controller, one for connecting to the PERMIT host and the other for connecting to a microcomputer. The controller is equipped with a built-in battery, which allows PERMIT to be used on site without an external power source. It also provides a DC power supply system along with PERMIT, which can be used with an external power source and can charge the built-in battery. Once the experiment is completed, the experimental data can be imported into a microcomputer for processing.

Technical Parameter
◇ Working voltage: 60 V DC
◇ Working temperature range: 0 ℃ -50 ℃
◇ Heat up time: 30 seconds