The two most common measurements made with a multimeter are: checking the mains AC in a socket, and checking the voltage across a Battery (to see if its charged or drained, and therefore needs recharging). The frequency of timers – which exist in numerous products – can be measured using a multimeter, speeding up fault finding and the search for a solution. In Audio products, Radios and Televisions the RF and Audio frequencies can be checked to enable detection and correction of problems. Also, both DC and AC voltages and currents can be checked at different stages to map the signal flow through a product.
With the increase in electronics in Cars, Vans, Lorries and Motor Bikes different types of leads are used – ones that allow stand-alone measurements in the engine control, battery control, lighting control, inside and outside environment control modules. In each of these the characteristics of the digital signals can be checked with pulse height ± voltage, width and frequency all displayed at the same time. DC voltage and current can also be checked using a multimeter, making it easier to check and fault-find in modules.
Appliances like Washing Machines, Cookers, Microwaves and Fridge/Freezers can all be checked using a multimeter – this replaces a complete setup of different test equipment and means no more returning products to a Workshop or Factory for repair. Different types of sensors can be checked using a multimeter: sensors checking temperature of the water for washing, cooking meat, fish or other food and for preserving such foods for different periods of cold storage.
A multimeter can be used to check all types of manufacturing systems. This means a hand held device can be deployed instead of one on a trolley; this has helped reduce response and repair times. The multimeter does have some restrictions: a lack of channels and being unable to display the entire signal(s) under observation, but for the first level of checks it does the task well.
Contactless measurements stop the signal from being attenuated by a digital multimeter and this can be used to prevent system failure. Radios, TVs, Microwaves and similar industrial systems can be checked while in operating mode. This is always the best way to observe how something is working and decide on what might be wrong and needs replacing. element 14 supplies these instruments through its Business Partner molex for clients in the Singapore region.
This article is contributed by Michael Kordas, Electronic Engineer.