Nowadays we are using more and more SMDs instead of legacy components with wire leads. That has the advantage that circuits can be made very compact, but it has disadvantages for building hobby circuits or prototypes. Many SMDs have markings that are either very cryptic or so small that you can’t read them. As a result, it is often difficult to tell resistors, capacitors and inductors apart from their external appearance. Fortunately there are some test equipment manufacturers that sell testers for passive SMDs, which look like overgrown tweezers with a display and some smart electronics. When you grasp an SMD with these tweezers, the display shows the component type and its value. Perfect!

R, C and L

However, good SMD testers are not cheap. The one we have been using for several years now in the Elektor Labs cost well above 200 euros. That’s a considerable expenditure for hobby use. There are also many low-cost SMD testers available with prices of a few tens of euros, but their main drawback is that they can only distinguish and measure resistors and capacitors. That’s not handy with more and more inductors being used in modern circuits for noise filtering and other purpose. The ability to recognise inductors is therefore a hard requirement. The least expensive Chinese model that I have found with LCR detection costs around 100 euros, which is still a significant amount. But now the Chinese company Mastech has launched the MS8911 SMD tester, which is able to detect resistors (R), capacitors (C) and inductors (L) and is priced under 40 euros. That sounds too good to be true, so we wanted to put this instrument to the test.

Many features

The tweezer contacts have notches.
Despite the low price, the MS8911 made a good impression when we took it out of the box. The housing is made of non-slip plastic, and the contacts on the tweezer tips are nicely finished. A spare set of contacts is also included. The user guide says they are gold plated, and they have a notch in the middle (see photo). That turns out to be very handy if you want to measure leaded components with the tester – that also works perfectly. It takes a fair amount of force to grasp a device with the tweezers, but maybe that will become easier after repeated use.