A robust and simple to use Joulemeter with autoranging LCD display. The units in which the values are displayed change automatically (e.g. between joules and kilojoules) and the decimal point automatically shifts so that three significant figures are always displayed. ?This means it can be used to measure from 100 nanojoules up to 1.75 megajoules without the need to make any manual adjustments. Readings are also logged, for download to a PC (if desired).The function button allows selection of the desired quantities to be measured: energy (J) and time (s); power(W); average power (W); voltage (V); current (A).The meter is powered via a single micro-USB socket, either using the mains adapter (included), or by connecting to a USB socket.? Current range: ?7A (current can flow in either direction)? Voltage range: ?25V? Log memory: 2500 samples; Sample period 1, 2, or 4 seconds? Powered via 5V mains adaptor (included) or USBTo measure the energy or power in a circuit or apparatus, a battery or bench power supply should be connected to the 4mm ?source? terminals, and the apparatus or component being measured (e.g. a bulb or 12V immersion heater) connected to the 4mm ?load? terminals.?Also available are spare/replacement internal 7A fuses, sold as a pack of 10.