How to Use an Analog Multimeter How to Use an Analog Multimeter
An analog multimeter is more delicate than a standard multimeter, and will likely break if dropped. An analog meter moves the needle across the scale and are less expensive than the other multimeter types. These meters are harder to read for beginners that are just starting out as the meter movement is very sensitive. A digital meter is generally better as it can handle larger currents such as 1M to 10M ohm, instead of the much lower 200K ohm on analog. The analog meter does make it easier to read slow alternating currents as the needle will reflect these electrical changes accurately where digital meters can not. This type of meter is quick to becoming absolute however, being replaced by digital meters that handle higher voltages. The concept and function of the multimeter is the same for functionality, they read voltages, resistances and current.
Step 1 - Measuring Voltages
For measuring voltages with your analog multimeter, you will want to connect it to the circuit in the appropriate place to get an accurate reading. As an example a circuit board set up in sequence with 4, 10K ohm resisters. Now you will use the multimeter as a voltmeter by checking the voltage readings on each of the resister poles in sequence, and then cross check your readings. These resisters connected in line create what is called a potential divider, and you should notice that each one is carrying the same voltages.
Step 2 - Measuring Resistances
You can get a good example of the readings on resistance using your analog multimeter, as a resistance ammeter. build or use a circuit with a light sensor along your circuit. The readings are taken from the poles of your resister itself. When you turn light on or off, you will notice a difference in the readings as the light sensor is going to change dramatically. In the dark your resistance should climb to 1M ohm, while in bright light the meter will read as low as 100 ohm. The reason for this is the light on the sensor floods the circuit with residual charge causing the reading to change as it gains power from another source.
Step 3 - Measuring Current
To measure actual current on an analog multimeter, build another circuit that is passing through 4, 10M ohm resisters, that close the circuit on your power source. Place your meter connections on the positive end of the circuit between the last resister and the power source. This will give you a reading of the current moving through the circuit flowing from negative to positive. To compare, check each resister from pole to pole and record your readings. You will notice, as you move from one circuit to another, the actual current increases the higher up the circuit you travel. As resistance increases, so does the movement of the current. One resister reading is going to be less current, than reading the poles from a second consecutive resister. These applications can be applied to any circuit board to test for failed components.