Tools & Measurement
There are many electrical tools and measuring instruments available on the market, of different brands and serving different purposes. Panel meters display an input signal. They take a sample of the input voltage or current and make a visual representation in digital or analogue form. Digital meters with numerical displays that emit precise readings represent the latest technology, but analog meters, simpler and with a needle display, are more suited for certain applications. Digital panel meters are best suited when the signal varies only slightly, over a large range, and when the signal is noisy. Analogue panel meters are better when the voltage is pulsing, as the needle makes it easier to track the pulse range. Another common measuring instrument is the multimeter, which measures electric current, voltage and resistance over several value ranges. Multimeters are available in digital and analogue versions, and also in handheld and desktop variants. Current clamp multimeters allow the device to be placed around a conductor. An oscilloscope measure changes in voltage of an electrical signal, displaying it in a waveform graph, with voltage sweeps on the Y-axis and time on the X-axis. This device, which is made in handheld and bench variants, is used to test the functionality of equipment that generates electrical signals.