Nasıl Yapılır Kullanılır a İşaretçi Multimetre?

(1) Önce test, birinci yer multimetre in a yatay durum ve kontrol eğer iğne is at sıfır (yönlendirme o sıfır nokta of the current ve voltaj ölçekler). If it is not, adjust the "mekanik sıfır ayarlama" alt metre kafa to make the pointer pointer point to zero.

(2) Seç doğru ölçüm öğeler ve aralık anahtarlar açık çokölçer tabanlı on ölçülen öğeler. Eğer sıra büyüklük varlık ölçülen bilinen, sonra seç tekabül eden aralık büyüklük. Eğer sıra büyüklük of ölçülen değer is bilinmeyen, the ölçüm olmalı başlangıç seçme seçici maksimum aralık. Ne zaman işaretçi sapma açı çok küçük to doğru oku 2c the aralık olmalı olmalı azaltılmış tekrar. The makul aralık genel tabanlı on a pointer sapma açı değil daha az 30 yüzde of the max scale.

The multimetre is kullanılan as a Ammetre:

① Ne zaman bağlanıyor a multimetre in seri in the circuit under test, attention should be paid to the direction of the current. Connect the red lead to the end where the current flows in and the black lead to the end where the current flows out. If you do not know the direction of current being measured, you can first connect a prob at one end of the circuit, ve nazikçe dokunma diğer prob at diğer son devrenin sonu eğer salıncaklar to the sağ, it gösterir o the kablolama is correct; If the pointer swings to the left (below zero), it gösterir yanlış kablolama. The positions of the two probes on the multimeter should be changed.

② Ne zaman işaretçi sapma açı daha büyük daha büyük veya eşit 30 yüzde of the maksimum ölçek, try to select a large number of range gears. Çünkü daha büyük the the measureing range, the smaller the shunt resistance and the smaller the eşdeğer internal resistance of the Ammeter, the smaller the error introduced by the circuit under test.

③ When measuring a large current (such as 500mA), do not move the range selection switch during the measurement process to avoid arcing and burning the contacts of the transfer switch.

The multimetre is kullanılan as a Voltmeter:

① Connect a multimeter in paralel to the circuit under test. When measureing DC voltage, pay attention to the polarity of the voltage at the measured point, that is, connect the red lead to the high voltage end and the black lead to the low voltage end. If you do not know the polarity of the voltage being measured, you can try the same probing method as before when when ölçme güncel. Eğer işaretleyici saptırılmış to sağda 2c siz can devam ile ölçüm; Eğer işaretleyici saptırılmış to sol, kırmızı ve siyah kalem konumlar olabilir ayarlanabilir to ölçüm.

② As with the above Ammeter, in order to reduce the error introduced by the internal resistance of the Voltmeter, when the pointer deflection angle is greater than or equal to 30 percent of the maximum scale, a large number of ranges shall be selected for measurement as far as mümkün. Çünkü the daha büyük the range, the greater the voltage divider resistance, the greater the equivalent internal resistance of the Voltmeter, and the smaller the error introduced to the circuit under test. If the internal resistance of the circuit to be measured is large, the internal resistance of the Voltmeter is required to be large, so that the measurement accuracy is high. At bu nokta, it gerekli için kullan a multimetre ile daha yüksek voltaj duyarlılık (daha büyük iç direnç) ölçüm.

③ Ne zaman ölçme AC gerilim, orada yok ihtiyaç düşün polarite sorunlar, as long as the multimeter is connected to both ends of the tested object in parallel. In addition, it is generally not required to select a large range or select a multimeter with high voltage sensitivity. Çünkü in general, the internal resistance of AC power is smaller than that of glue. O değer kayda değer bu ölçülen AC gerilim can sadece be a sinüs dalga, ve its frekans olmalı olmalı daha az veya eşit to the allowable working frekans of the multimeter, otherwise important errors will occur.

④ Do not move the range selection switch when measureing a higher voltage (such as 220V) to avoid generating an arc and burning the contact of the transfer switch.

⑤ When measuring the high voltage greater than or equal to 100v, it is necessary to pay attention to safety. It is better to fix one stylus in the common part of the circuit under test first, and then use another stylus to touch the other end of the Test point.

⑥ In circuit systems, the level is commonly used to represent the effective value of the voltage at that point. Therefore, the multimeter has a level scale on the AC voltage range, and zero level refers to the power generated at a 600 ohm impedance of 1mW, which corresponds to a voltage effective value of 0.75V. If the impedance of the broken circuit is not equal to 600 ohms, the calculation should be carried out according to the following formula: actual electronic value=multimeter dB reading plus 101g (600/z). In the formula, z is the resistance value of the tested circuit. It is worth noting that the measurement should be placed on the 10V level, because the level scale of the multimeter is designed and calculated on that level. If the range is not enough, it needs to be changed to another level for measurement. The multimeter is only suitable for measuring volume and frequency levels, such as DC voltage on the circuit, It is also necessary to connect a 0.1uF/450V capacitor in series to isolate the DC before measuring it

⑦ Ne zaman ölçme gerilim in an endüktif devre, multimetre zorunluluk be bağlantısız önce dönüş kapalı güç sonra ölçüm. Aksi takdirde, ne zaman kesme kes güç kaynak, vadeli to kendini endüktans indüktif indüktif bileşenler indüktif devre, yüksek voltaj olabilir olabilir üretilebilir ve multimetre olabilir olabilir yanmış dışarı.