These ultra-cheap multimeters have been around for a long time. I bought one in 2005 for 4.50euro while I was on holiday in Portugal. It seemed amazingly cheap at the time, but subsequently even Maplin in the UK started selling multimeters for a fiver!
My cheap meter looks like the same design as Joe's picture, but made of yellow plastic. I suspect the black cased ones are made from a proportion of recycled plastic, hence they are slightly cheaper.
Internally, it uses a single chip - the ICL7106 - to carry out the functions of converting analogue voltage to a digital value and driving the LCD. For the curious, the datasheet for the IC is available here: http://www.alldatasheet.com/datasheet-pd...06CPL.html
Presumably the ICL7106 chip used in these cheap meters is a Chinese copy of the original ones that were developed in the USA a long time ago. Perhaps the patent has expired?
Some people have warned that some of these very cheap multimeters may not be safe to use on high voltages, even though they have a 1000V input range. I'm not sure exactly what the issues are, but I reckon Mark Hennessy, our test equipment guru, could advise.
Nevertheless, these cheap meters are handy to keep in the car for low-voltage measurements and continuity tests.
My cheap meter looks like the same design as Joe's picture, but made of yellow plastic. I suspect the black cased ones are made from a proportion of recycled plastic, hence they are slightly cheaper.
Internally, it uses a single chip - the ICL7106 - to carry out the functions of converting analogue voltage to a digital value and driving the LCD. For the curious, the datasheet for the IC is available here: http://www.alldatasheet.com/datasheet-pd...06CPL.html
Presumably the ICL7106 chip used in these cheap meters is a Chinese copy of the original ones that were developed in the USA a long time ago. Perhaps the patent has expired?
Some people have warned that some of these very cheap multimeters may not be safe to use on high voltages, even though they have a 1000V input range. I'm not sure exactly what the issues are, but I reckon Mark Hennessy, our test equipment guru, could advise.
Nevertheless, these cheap meters are handy to keep in the car for low-voltage measurements and continuity tests.
