In this article, we will describe the effectiveness of the Hill Hill Instruments Four-Probe Resistance Tester on samples that do not meet semi-unbounded conditions, such as thickness between 10 times the probe pitch (10 mm) and 01x probe spacing (01 mm) and samples with a diameter of less than 100 mm. The Smart FPP software can automatically correct the measurement results according to the geometric parameters of the sample, so that users can easily obtain the square resistance, resistivity, conductivity and other information of the sample without considering various usage conditions.
The resistivity of a non-semi-unbounded sample needs to be formulated in the formula
On the basis of the correction, the formula is obtained
Among them, f1 is the correction coefficient of the probe, which is used to correct the factory deviation of the probe, which is provided by the manufacturer and is a constant close to 1.
f2 is the thickness correction factor when the sample thickness is 0This correction factor is required between 4 mm and 4 mm. The f2 value can be obtained from Table 1. When the thickness of the sample is greater than 4 mm, the sample can be considered to be a semi-unbounded sample in the thickness direction, which can be determined by the formula
The resistivity of the sample is directly obtained. As can be seen from Table A, when the sample thickness is less than 0At 62 mm, the error caused by ignoring the thickness correction factor is less than 1%, which is acceptable in most scenarios.
Figure A shows the f2 as a function of thickness.
f3 is the correction factor for the sample diameter, which can be used when the sample diameter is between 10 mm and 200 mm. The f3 value can be obtained from Table 2. When the sample diameter is greater than 200 mm, the semi-unbounded condition is satisfied, and F3 is close to one and is negligible. Again, as can be seen from Table 2, when the sample diameter is greater than 28At 6 mm, ignoring F3 results in an error of less than 1%, which is acceptable in most scenarios. When the sample diameter is greater than 100 mm, ignoring f3 results in an error of less than 01%。
Figure B shows the F3 as a function of the sample diameter.
At this point, the principle of the four-probe resistance tester of the Qiushan instrument, as well as the calculation of the resistivity of samples with different geometric characteristics and the correction coefficients have been introduced. For general users, these principles do not need to be in-depth understanding, the product engineer of Qiushan Instrument four-probe resistance tester has taken these situations into account when designing products, general users only need to input sample thickness and diameter information on Qiushan Instrument Resistance Tester, and the Smart FPP software supporting Qiushan Instrument Four-Probe Resistance Tester will judge the applicable conditions and corresponding correction coefficients by itself, so that users can easily obtain accurate sample resistivity and other parameters. For more information, please visit the official website of Qiushan Instrument