Cheap Cen-Tech Multimeters

The Harbor Freight Cen-Tech multimeter is about $4 or less.  It measures voltage to 1000V DC/750V AC, current to 10A DC, resistance to 2MOhms, diode voltage.  It also has a battery tester (360Ohm load) and transistor tester for measuring gain.  It has 3-1/2 digit LCD display.  It is reasonably accurate (generally within 0.1%) and well worth the money.  But keep in mind the input resistance for the voltage measurement is 1MOhms.  The shunt resistance for 10A is about 0.016 Ohms.

Maybe it is a sign that the price cannot sustain; the more recent model starts to skimp on the probes with smaller conductors, adding 0.5Ohms to each of the probe.  The probe wire feels warm when carrying a few amperes of current. The probe lead will fuse before the fuse does.

The battery tester load is convenient when you just need a small load for testing, such as checking an LED.   The current measurement settings can also let you test connect two nodes with different resistances 1K, 100, 10, 1 and 0.01Ohms.  You can use the 1MOhm input resistance of the voltage measurement settings for a weak pull-up or pull-down.  The resistance settings can source voltages, but they are load dependent.  You can use the 200-Ohm setting to turn on a logic input; it puts out 3V when the input resistance is at 50K or above and 2.5V at about 7K.  Other settings can only output about 0.6V max.  The diode setting outputs 1mA when measuring diode voltage; it outputs 3V max but at 0.5mA.