I skimped out and bought a $20 multimeter - it's now one of my best toolkit investments

"If you make a living with your tools, you need them to handle day-to-day usage. The problem is, pro-grade, high-end tools are pricey and can be out of the reach of the amateur DIYer. As far as multimeters go, I like the meter. It's a compact pen-type multimeter that connects to a smartphone and does everything that I need from a multimeter."

"This is a compact multimeter that handles all the basics -- AC/DC voltages, resistance, diode test, non-contact voltage testing, and capacitance -- as well as a few advanced features such as ambient temperature, AC frequency, and live and phase sequence identification. The unit is a 6,000-count, so it offers a higher level of resolution than cheaper 3,000- or 4,000-count units, allowing it to show values to three decimal places at 6V, as opposed to two."

Compact, pen-type Neoteck TS20D provides essential and advanced multimeter functions, including AC/DC voltage, resistance, diode testing, non-contact voltage detection, capacitance, ambient temperature, AC frequency, and live and phase sequence identification. The unit uses a 6,000-count display for higher resolution than common 3,000- or 4,000-count meters, showing three decimal places at low voltages. Accuracy is ±1% for AC and ±0.8% for DC, suitable for most DIY needs. The meter lacks current (amperage) measurement; clamp meters are recommended for amperage to avoid blowing fuses. The unit carries a CAT II rating up to 600V for domestic mains use.

Read at ZDNET