【正文】 erature coefficient thermistor (PTC) detection. 檢測時，用萬用表 R1 擋，具體可分兩步操作： A 常溫檢測 ( 室內(nèi)溫度接近 25 ℃ ) ；將兩表筆接觸 PTC 熱敏電阻的兩引腳測出其實際阻值，并與標稱阻值相對比，二者相差在177。 Detection with a multimeter R 1 block, concrete can be a twostep operation:temperature detection (indoor temperature close to 25 ℃)。 2 Ω in the normal. 實際阻值若與標稱阻值相差過大，則說明其性能不良或已損壞。heat detection。 Be careful not to make the heat source and the PTC thermistor by too close or direct contact thermal resistance, in order to prevent their Tanghuai. 6 負溫度系數(shù)熱敏電阻 (NTC) 的檢測6. negative temperature coefficient thermistor (NTC) detection. (1) 、測量標稱電阻值 R(1), measured nominal resistance value Rt 用萬用表測量 NTC 熱敏電阻的方法與測量普通固定電阻的方法相同，即根據(jù) NTC 熱敏電阻的標稱阻值選擇合適的電阻擋可直接測出 Rt 的實際值。 But NTC thermistor is sensitive to temperature, so testing should note the following: Rt is a manufacturer of environmental temperature measured at 25 ℃, so the measure with the multimeter Rt should also be at ambient temperature when close to 25 ℃ in order to ensure the credibility test. B 測量功率不得超過規(guī)定值，以免電流熱效應(yīng)引起測量誤差。 attention to proper operation. 測試時，不要用手捏住熱敏電阻體，以防止人體溫度對測試產(chǎn)生影響。First measured at room temperature under t1 resistance Rt1, electric iron to heat and then, near the thermistor Rt, measure the resistance RT2, the same time, measured with the thermometer at this time the surface of the thermistor RT and then calculated the average temperature t2. 7  testing. 用萬用表的 R1k 擋測量壓敏電阻兩引腳之間的正、反向絕緣電阻，均為無窮大，否則，說明漏電流大。If the measured resistance is very small, shows varistors have been damaged and can not be used. 8 光敏電阻的檢測。 This value shows the bigger the better performance of lightsensitive resistors. 若此值很小或接近為零，說明光敏電阻已燒穿損壞，不能再繼續(xù)使用。 will be a light source aligned photosensitive resistance translucent window, this time multimeter pointer should be more substantial swing, resistance significantly reduced. 此值越小說明光敏電阻性能越好。 If this value is great or even infinite, indicating that the internal resistance of open photosensitive damage, can no longer continue to 將光敏電阻透光窗口對準入射光線，用小黑紙片在光敏電阻的遮光窗上部晃動，使其間斷受光，此時萬用表指針應(yīng)隨黑紙片的晃動而the photosensitive resistance translucent window aligned incident light line, with the black pieces of paper in the upper window shading photosensitive resistor shaking to break by the light, this time with the black pieces of paper multimeter pointer should be about the rock and swing. 如果萬用表指針始終停在某一位置不隨紙片晃動而擺動，說明光敏電阻的光敏材料已經(jīng)損壞。10pF capacitors due to the following fixedsize too small to measure with the multimeter, only a qualitative check whether there is leakage, the internal short circuit or breakdown phenomenon. 測量時，可選用萬用表 R10k 擋，用兩表筆分別任意接電容的兩個引腳，阻值應(yīng)為無窮大。 If the measured resistance (pointer to the right swing) is zero, then capacitor leakage damage or internal breakdown. B 檢測 10PF ～ 0  01 μ F 固定電容器是否有充電現(xiàn)象，進而判斷其好Detection 10PF ~ μ F capacitor whether there is a fixed charge phenomenon, and then judge its good or bad. 萬用表選用 R1k 擋。 2 transistor β values are above 100, and the current penetration is smaller. 可選用 3DG6 等型號硅三極管組成復合管。 Multimeter39。 As the posite transistor amplification, the process of charging and discharging capacitor under test to be larger, so that the pointer of swing meter increase, and thus easy to observe. 應(yīng)注意的是：在測試操作時，特別是在測較小容量的電容時，要反復調(diào)換被測電容引腳接觸 A 、 B 兩點，才能明顯地看到萬用表指針的擺動。 For μ F or above a fixed capacitor can be used multimeter R 10k block directly test whether the process of charging capacitor, as well as whether the internal short circuit or leakage, and can swing under the pointer to the right size to estimate the magnitude of the capacity of capacitors . 2 電解電容器的檢測2. electrolytic capacitor testing A 因為電解電容的容量較一般固定電容大得多，所以，測量時，應(yīng)針對不同容量選用合適的量程Because the capacity of electrolytic capacitors is much greater than the average fixed capacitor, therefore, measurements should be the appropriate choice of different capacities range. 根據(jù)經(jīng)驗，一般情況下， 1 ～ 47 μ F 間的電容，可用 R1k 擋測量，大于 47 μ F 的電容可用 R100 擋測量。The multimeter red pen then negative, then positive black table pen, in the new to the moment, multimeter pointer that the right side deflection of a larger degree (for the same power to block the capacity the greater the greater the swing), and then gradually to the left turn, until the stop at a certain location. 此時的阻值便是電解電容的正向漏電阻，此值略大于反向漏電阻。 Actual experience has shown that the leakage resistance of electrolytic capacitors in general should be more than a few hundred k Ω, otherwise, it will not work properly. 在測試中，若正向、反向均無充電的現(xiàn)象，即表針不動，則說明容量消失或內(nèi)部斷路；如果所測阻值很小或為零，說明電容漏電大或已擊穿損壞，不能再使用。if the measured resistance of very small or zero, indicating large capacitor leakage or breakdown damaged, can not be used again. C 對于正、負極標志不明的電解電容器，可利用上述測量漏電阻的方法加以判別。 Which is to look at any measure leakage resistance, remember its size, and then swap the table T and then measured by a resistance. 兩次測量中阻值大的那一次便是正向接法，即黑表筆接的是正極，紅表筆接的是負極。 power to block the use of multimeter, using electrolytic capacitors to be positive, the reverse charge method, according to the size of a pointer to the right swings can estimate a capacity of electrolytic capacitors. 3 可變電容3. variable capacitor testing A 用手輕輕旋動轉(zhuǎn)軸，應(yīng)感覺十分平滑，不應(yīng)感覺有時松時緊甚至有卡滯現(xiàn)象。 Will contain the axial front, back, up, down, left and right in various directions and promotion, the shaft should not be loose phenomenon. B 用一只手旋動轉(zhuǎn)軸，另一只手輕摸動片組的外緣，不應(yīng)感覺有任何松脫現(xiàn)象。 Poor contact between the shaft and the moving film of the variable capacitor, can not continue to use. C 將萬用表置于 R10k 擋，一只手將兩個表筆分別接可變電容器的動片和定片的引出端，另一只手將轉(zhuǎn)軸緩緩旋動幾個來回，萬用表指針都應(yīng)Will be placed in R 10k block multimeter, a pen in hand the two tables were then fixed variable capacitor chips and fixed film leads to side, the other hand to slowly rotating shaft a few back and forth, multimeter pointer are infinite position should be fixed. 在旋動轉(zhuǎn)軸的過程中，如果指針有時指向零，說明動片和定片之間存在短路點；如果碰到某一角度，萬用表讀數(shù)不為無窮大而是出現(xiàn)一定阻值，說明可變電容器動片與定片之間存在漏電現(xiàn)象。 If you hit a certain point of view, multimeter reading is not infinite, but many will certainly resistance, indicating a variable capacitor move exi