できる a マルチメータ be 使用済み to 検索 アウト the poor contact of the public neutral line?
Look, in fact, many people think that only when the neutral line is broken, the zero point drift will be caused. In fact, it is not the case. When it is not broken but the connector is weak, the zero point has already drifted. (When starting an electrical appliance with several hundred watts), who is broken? It will be measured, but when it is a virtual connection, some people will not know it. In fact, it is simple. In your power distribution room or distribution box, it is your superior power distribution place (there must be three-phase power), and use 220v voltage for measurement. File test, measure the voltage of each phase, under normal circumstances, each phase is the same (there can also be a small error), but when the neutral line is virtual connected, the performance of the three phases is different, you know? As the virtual connection worsens, the voltage gap becomes larger, but this method is performed when it is about to be disconnected.
別の メソッド is to see that when the neutral line is not connected 適切に, whenever you use a 高電力 電気 電化製品, if you turn on the light, you will see the lamp flickering. this is the early performance, but It is recommended that you check the line 頻繁に and try to avoid such problems, which will 間違いなく 原因 損失。
The 静電容量 値 測定 by the マルチメータ is 常時 変化する
どちらか the circuit is 不安定, または the multimeter is dying
The refresh rate display by the digital multimeter is about 3 times per second, so it is normal to change. but if it jumps wildly, it is wrong, and the possible reason is that the contact is not good. general, it is the test lead and the circuit under test, or the test lead and the multimeter それ自体, and it is also possible that the multimeter jack is not 井戸 溶接, the マルチメータ スイッチ IS IN コンタクト, the バッテリー IS 不十分, および SO ON。
The ステップ to test the quality of コンデンサ with a digital multimeter are as follow:
1. To 決定 the 極性, first adjust the multimeter to the 100 or 1K ohm range. Assume that one pole is positive, connect the black test lead to it, and connect the red test lead to the other pole. write down the 抵抗 value, and then 放電 the コンデンサ, that is, let the two poles contact, and then change the test lead to measure the resistance. the black テスト リード あり A 大きい 抵抗 値 IS 接続済み に ポジティブ 電極 の その コンデンサ。
2. 調整 the マルチメータ to the 適切 ギア of the ohm range. the principle of gear selection is: 1μF コンデンサ use 20K gears, {{{3}μF コンデンサ use 2K gears, and コンデンサ より大きい より大きい 100, μF use 200 gears.
3. その後 使用 赤 ペン の の マルチメータ to 接続 その 正 極 の の コンデンサ, および その 黒 ペン に その 負 極 の コンデンサの もし その 表示 増加 ゆっくり から {0, そして 最後に ディスプレイ the オーバーフロー シンボル 1, the コンデンサ is normal. if it always show 0, the コンデンサ is 短絡 内部的に. If 1 is 表示, the コンデンサ is 内部 途切れ途切れ。
