周末暖场活动-夏日养生图文.ppt

The use of Ammeters and Voltmeters 电流表、电压表的使用
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Analogue Display
Analogue displays have a pointer which moves over a graduated scale. They can be difficult to read because of the need to work out the value of the smallest scale division. For example the scale in 10 small divisions between 0 and 1 so each small division represents .
The maximum reading of an analogue meter is called full-scale deflection or FSD.
模拟显示器
模拟显示器有一个指针,该指针可以在刻度盘上转动。因此需要计算出最小的刻度分割值,所以读数困难。如图所示,刻度在0和1之间有10个分割,.
模拟表的最大读数称为满刻度偏转
或FSD.
Take accurate reading
To take an accurate reading from an analogue scale you must have your eye in line with the pointer. Avoid looking at an angle from the left or right because you will see a reading which is a litter too high or too low. Many analogue meters have a small strip of mirror along the scale to help you . When your eye is in the correct position the reflection of the pointer is hidden behind the pointer itself. If you can see the reflection you are looking at an angle.
获得精确的读数
为了从模拟表盘上得到精确的读数,你应该保持你的眼睛和指针一条线。避免左偏或右偏,因为那样你将得到一个或高或低的读数。为了有助于你读数,许多模拟仪表的刻度有一个小条或镜子,当你的眼睛位置正确时,你就看不到指针的偏差。如果你看到偏差,你的视线就存在一个偏角。
Connecting meters
It is important to connect meters the correct way round:
The positive terminal of the meter ,marked + or coloured red should be connected nearest to + on the battery or power supply.
The negative terminal of the meter - or coloured black should be connected nearest to - on the battery or power supply.
仪表的连接
按正确的方式连接很重要:
表的正极,标+或涂成红色,应该接在电池或电源的+极。
表的负极,标—或涂成黑色,应该接在电池或电源的—极。
Voltmeters电压表
symbol of voltmeter
Voltmeters measure voltage.
电压表测量电压
Voltage is measured in volts, V
电压的单位是伏特,v
Voltmeters are connected in parallel ponents.
电压表并联在元件的两端
Voltmeters have a very high resistance.
电压表有一个很高的内阻。
Ammeter
Ammeters measure current.
Current is measured is amps ,A.
Ammeters are connected in series.
To connect in series you must break the circuit and put the ammeter across the gap, as shown in the