Experiment 10 intelligent use of low resistance tester.docx

Experiment 10 intelligent use of low resistance tester And the determination of resistivity 1 purpose of the experiment 1) Learning Intelligent use of low-resistance testing methods; 2) Learning linear conductive material resistivity measurement method. 2 Experimental apparatus Intelligent low resistance tester, tested resistance, resistance wire, micrometer, meter stick. 3 Principle Resistivity 3.1 Resistivity of the material is to describe the physical properties of conductive material. Material resistivity and temperature, the resistivity of the conductor with the increase of temperature. Resistivity of some materials also humidity, light intensity, the magnetic field is related to the practical application of these materials are often applied to make sensitive device. In exactly the same conditions, such as the same length, same shape, the same temperature, only material is not the same time, resistance to a large resistivity large. 3.2 The electrical resistance measurement method Usually tested the material into a uniform thickness of the sample linear material, such material and its resistance proportional to the length, size and material of the cross-sectional area is inversely proportional to the resistivity of the material is proportional to, namely: Where R is resistance, l is length, d is not thread diameter. Therefore, the resistivity can be drawn Determination: Experiment as long as the measured resistance of the material, length and diameter, they can determine the resistivity. In this study, low-resistance measuring instrument with a precision measurement of resistance, measured with a meter stick length, measured with a micrometer in diameter. 4 TH2512B Smart Low Resistance Tester See textbooks Add two points (1) short circuit is cleared clamp method (2) sorting capabilities Sorting (quality discrimination) Help 1. Sorting Function a. You can use the sorting feature of this instrument for quality control of manufactured products (QC), press the front panel of the sorting key, the Select ON lights after midnight, the instrument into the sorting state. At this point the user can select display shows the measured resistance value and percentage Deviation, where the percentage deviation = 100%, while the percentage deviation % less than the negative limit, the instrument indicates LOW light, when more than % is the limit, the instrument indicates HIGH light, or instrument indicating PASS Liang, PASS buzzer will sound when the instrument, users can switch the rear panel of inquiry cut off the hearing loud sound. b. Press the sorting buttons, then the comparator ON, this time scale can not be changed, and displayed as a percentage value, For Reading test Value, just press the display button, R can be chosen. To read or change the nominal value, the value of % upper and lower limits, set by set to enter the state. c. Comparison of results can be panel HIGH, PASS, LOW instructions. d. To exit the separation state, only then sorting key once. 2. This section describes how to set the nominal value of % upper and lower limit value (which is the user a prerequisite for sorting products), the method as follows: a. the user first selected according to the size range tested resistance, but also acquire a folder tested resistors in the test side, so that the instrument automatically selected To the desired range, and then lock range. b. Press the set key and the instrument will show-STD-about 0.5 seconds, then displays the nominal value to be set, available , , key operational adjustments, until the nominal value of the compliance requirements. then press the Set button, the display shows-LO-about 0.5 seconds, and then set the display to be a negative value of % limit, with the key operation to adjust, until required. again press the setting button, the display shows-HI-0.5 seconds, then displays to be set % is the limit value, with , , key operation to adjust, until required. and then press the Set button, the instrument will exit the setting mode, the end of the set, for testing. c. At this point, the user can set the value according to the sorting out. d. the user to set upper and lower limits of the nominal value and the value of % is still valid at the next boot, but it should be noted that the range corresponds to the nominal value. Note: This machine is seven test ranges, range from 20m to 20k range, jumping 10 times each file the standard set by the user Said in a different range of values corresponding to different times, so users should be selected for the test range, and then set the nominal value used for sorting. 5 experimental content and procedures 5.1 Resistance Measurement 1) be familiar with the instrument panel structure and method of use; 2) the resistance of a given repeated measurements. 5.2 Measurement of resistivity 1) with repeated measurements of low resistance tester resistance wire resistance; 2) repeated measurements with a micrometer the diameter of resistance wire; 3) Repeat with the meter stick measure the length of resistance wire. 6 Data processing requirements 1) The following are the resistivity：oCr21A14 1.23（m） Cr15Ni60 1.091.200.05（m） oCr21A16 1.420.07（m） oCr23A15 1.350.06（m）Table 1 oCr21A14 Fe-Cr alloy resistivity data measured (6.5 / md(cm)R（）L（cm）0.5023.46753.700.5023.46153.750.5023.46353.720.5003.46153.700.5013.46153.680.5013.46553.650.5020.5010.503 The above data were judged not bad valueTable 2 Cr15Ni60 nichrome resistivity data measured (5.65 / m)L（cm）d(cm)R（）48.200.5002.69948.25（坏值）0.5002.69648.180.5002.69748.200.4982.69648.200.4982.69148.210.4992.701The above data has been judged by Xiaowei Nie criteriaTable 3 oCr21A16 Fe-Cr alloy resistivity data measured (7.28 / m).d(cm)R（）L（cm）0.5073.58249.310.5033.58349.300.5083.58449.300.5073.57549.310.5073.57649.290.5093.58649.290.505The above data to determine criteria by Xiaowei Nie no bad valuesTable 4 oCr23A15 Fe-Cr alloy resistivity data measured (6.89 / m)d(cm)R（）L（cm）0.5142.90842.700.5172.90442.650.5132.90742.650.5172.91142.680.5152.90442.700.5202.91042.650.5102.9120.5202.907The above data to