【正文】 phenomenon. 將載軸向前、后、上、下、左、右等各個(gè)方向推動(dòng)時(shí)，轉(zhuǎn)軸不應(yīng)有松動(dòng)的現(xiàn)象。 Two measurements of resistance and that one is a big positive then the law, that the black pen then the table is positive, the red pen then the table is the negative. D 使用萬(wàn)用表電阻擋，采用給電解電容進(jìn)行正、反向充電的方法，根據(jù)指針向右擺動(dòng)幅度的大小，可估測(cè)出電解電容的容量。C for the positive and negative signs unknown electrolytic capacitors can be measured using the above method to determine leakage resistance. 即先任意測(cè)一下漏電阻，記住其大小，然后交換表筆再測(cè)出一個(gè)阻值。 In the test, if positive, no charge reverse phenomenon, namely,needle not move, then lost the capacity or the internal circuit。 At this point the resistance is positive electrolytic capacitor leakage resistance, this value is slightly larger than the reverse leakage resistance. 實(shí)際使用經(jīng)驗(yàn)表明，電解電容的漏電阻一般應(yīng)在幾百 k Ω以上，否則，將不能正常工作。 Based on experience, under normal circumstances, 1 ~ 47 μ F between the capacitance, R 1k block can be measured, greater than 47 μ F capacitor can be used R 100 block measurement. B 將萬(wàn)用表紅表筆接負(fù)極，黑表筆接正極，在剛接觸的瞬間，萬(wàn)用表指針即向右偏轉(zhuǎn)較大偏度 ( 對(duì)于同一電阻擋，容量越大，擺幅越大 ) ，接著逐漸向左回轉(zhuǎn)，直到停在某一位置。 It should be noted: In the test operations, especially in the measured capacitance of a smaller capacity, they must repeatedly exchange the measured capactance pin contacts A, B two points, in order to clearly see the multimeter pointer swing. C 對(duì)于 0  01 μ F 以上的固定電容，可用萬(wàn)用表的 R10k 擋直接測(cè)試電容器有無(wú)充電過(guò)程以及有無(wú)內(nèi)部短路或漏電，并可根據(jù)指針向右擺動(dòng)的幅度大小估計(jì)出電容器的容量。s red and black table pen and posite pipe, respectively e emitter and collector cphase. 由于復(fù)合三極管的放大作用，把被測(cè)電容的充放電過(guò)程予以放大，使萬(wàn)用表指針擺幅度加大，從而便于觀察。 Can choose 3DG6 silicon transistor models such as the position of posite pipe. 萬(wàn)用表的紅和黑表筆分別與復(fù)合管的發(fā)射極 e 和集電極 c 相接。 Multimeter selected R 1k block. 兩只三極管的β值均為 100 以上，且穿透電流要小。 Measurements, it can use multimeter R 10k block, using two tables T 2 respectively, the capacitance of arbitrary access pin, resistance should be infinite. 若測(cè)出阻值 ( 指針向右擺動(dòng) ) 為零，則說(shuō)明電容漏電損壞或內(nèi)部擊穿。 If the meter pointer is always parked in a certain location does not rock and sway with the pieces of paper, indicating the photosensitive photosensitive resistance materials have been damaged. 二、電容器的檢測(cè)方法與經(jīng)驗(yàn)Ⅱ. capacitors detection methods and experience 1  of the fixed capacitor A 檢測(cè) 10pF 以下的小電容Detect the small capacitance below ,因 10pF 以下的固定電容器容量太小，用萬(wàn)用表進(jìn)行測(cè)量，只能定性的檢查其是否有漏電，內(nèi)部短路或擊穿現(xiàn)象。 The smaller this value shows the better performance of lightsensitive resistors. 若此值很大甚至無(wú)窮大，表明光敏電阻內(nèi)部開(kāi)路損壞，也不能再繼續(xù)使用。 If this value is very small or close to zero, indicating photosensitive resistor has burn damage, can no longer continue to be used. B 將一光源對(duì)準(zhǔn)光敏電阻的透光窗口，此時(shí)萬(wàn)用表的指針應(yīng)有較大幅度的擺動(dòng)，阻值明顯減小。8. photosensitive resistance 用一黑紙片將光敏電阻的透光窗口遮住，此時(shí)萬(wàn)用表的指針基本保持不動(dòng)，阻值接近無(wú) black pieces of paper with a translucent window, the photosensitive resistor cover, this time multimeter pointer remained motionless close to infinite resistance. 此值越大說(shuō)明光敏電阻性能越好。With the multimeter measuring R 1k block varistors are between the two pins, reverse insulation resistance, are infinite, otherwise, indicating leakage current. 若所測(cè)電阻很小，說(shuō)明壓敏電阻已損壞，不能使用。 Test, do not pinch fingers thermistor body, in order to prevent the body temperature of the test impact. (2) 、估測(cè)溫度系數(shù)α t(2), estimate the temperature coefficient αt 先在室溫 t1 下測(cè)得電阻值 Rt1 ，再用電烙鐵作熱源，靠近熱敏電阻 Rt ，測(cè)出電阻值 RT2 ，同時(shí)用溫度計(jì)測(cè)出此時(shí)熱敏電阻 RT 表面的平均溫度 t2 再進(jìn)行計(jì)算。 measuring power shall not exceed the specified value in order to avoid current heating effect caused by measurement error. C 注意正確操作。NTC thermistor with the multimeter measuring methods and measured the same way as ordinary fixed resistor that, according to the nominal resistance of NTC thermistor select the appropriate power block can be directly measured the actual value of Rt. 但因 NTC 熱敏電阻對(duì)溫度很敏感，故測(cè)試時(shí)應(yīng)注意以下幾點(diǎn)： A  Rt 是生產(chǎn)廠家在環(huán)境溫度為 25 ℃時(shí)所測(cè)得的，所以用萬(wàn)用表測(cè)量 Rt 時(shí)，亦應(yīng)在環(huán)境溫度接近 25 ℃時(shí)進(jìn)行，以保證測(cè)試的可信度。 at room temperature, on the basis of the tests are normal, you can carry out the second step tests heat detection, will be a heat source (for example, iron) near the PTC thermistor to its heating, while monitoring its resistance with the multimeter whether it increases with increasing temperature which, in the case shows that the thermistor to normal, if no change in resistance, indicating inferior performance changes are not in use. 注意不要使熱源與 PTC 熱敏電阻靠得過(guò)近或直接接觸熱敏電阻，以防止將其燙壞。 Resistance if it is the actual difference between the nominal resistance value is too large, its performance is illustrated in bad or damaged. B 加溫檢測(cè)；在常溫測(cè)試正常的基礎(chǔ)上，即可進(jìn)行第二步測(cè)試 加溫檢測(cè)，將一熱源 ( 例如電烙鐵 ) 靠近 PTC 熱敏電阻對(duì)其加熱，同時(shí)用萬(wàn)用表監(jiān)測(cè)其電阻值是否隨溫度的升高而增大，如是，說(shuō)明熱敏電阻正常，若阻值無(wú)變化，說(shuō)明其性能變劣，不能繼續(xù)使用。 the two tables sum of the two contact pins PTC thermistor measured the actual resistance, and with the pared to the nominal resistance, both of difference shall be within 177。 2 Ω內(nèi)即為正常。 When the shaft rotating handle to its extreme position 3, the resistance should be close to the nominal value potentiometer. 如萬(wàn)用表的指針在電位器的軸柄轉(zhuǎn)動(dòng)過(guò)程中有跳動(dòng)現(xiàn)象，說(shuō)明活動(dòng)觸點(diǎn)有接觸不良的故障。s file with the multimeter test 1, 2 (or 2, 3) at both ends of the potentiometer counterclockwise rotation of the shaft according to nearly off position, then the smaller the resistance value better. 再順時(shí)針慢慢旋轉(zhuǎn)軸柄，電阻值應(yīng)逐漸增大，表頭中的指針應(yīng)平穩(wěn)移動(dòng)。 detect the activities of potentiometer arm and the contact resistance is a good film. 用萬(wàn)用表的歐姆檔測(cè) 1 、 2( 或 2 、 3) 兩端，將電位器的轉(zhuǎn)軸按逆時(shí)針?lè)较蛐两咏? 關(guān) 的位置，這時(shí)電阻值越小越好。Check potentiometer, the first rotating rotary handle, turn handle to see if rotation is smooth, the switch is flexible, switch pass, off time Cameroon clatter sound is crisp, and listen to a potentiometer, and resistors within the contact points of friction sound, if imperfections sound, indicating poor quality. 用萬(wàn)用表測(cè)試時(shí)，先根據(jù)被測(cè)電位器阻值的大小，選擇好萬(wàn)用表的合適電阻擋位，然后可按下述方法進(jìn)行檢測(cè)。 For the surface without any trace of the fuse resistor to judge good and bad, can draw support from multimeter to measure the R 1 block, in order to ensure measurement accuracy, should fuse resist